RU2766333C1 - New n4-modified 5-methyl-2'-deoxycytidines exhibiting antimicotic activity - Google Patents

Abstract

FIELD: organic chemistry.

SUBSTANCE: invention relates to the field of organic chemistry and microbiology and is intended to suppress the growth of fungi that are biodestructors of cultural heritage objects. New N⁴-derivatives of 5-methyl-2’-deoxycytidine are proposed, represented by the general formula where: R₁ and R₂ independently mean: R₁= -C_nH_2n+1, -OC_nH_2n+1 (n=8-12); R₂= -OH, -N₃, -NH₂, -NHC(O)CH₃, -N(CH₃)₂, -NHC₂H₅, -N(C₂H₅)₂, -O(CH₂CH₂O)₃H, which are capable of suppressing the growth of mycelial fungi.

EFFECT: effective inhibition of the growth of fungi biodestructing cultural heritage objects.

2 cl, 6 dwg, 1 tbl, 23 ex

Description

The field of technology to which the invention belongs

The invention relates to molecular biology and microbiology, and in particular to the use of new derivatives of N ⁴ -derivatives of 5-methyl-2'-deoxycytidine to suppress the growth of filamentous fungi.

State of the art

Communities of microorganisms play one of the key roles in the biodamage of cultural heritage objects due to their ability to enzymatically decompose leather, oil, casein, glue, stones and other materials used in works of historical art [Sterflinger K. Fungi: Their role in degradation of cultural heritage. Fungal Biol Rev. 2010, 24, 47-55. doi:10.1016/J.FBR.2010.03.003]. Mushrooms from different systematic groups can damage many art objects: from oil painting on canvas, tempera painting, parchment, stone monuments to exhibits of entire museums, libraries, monasteries, rock paintings, frescoes in grottoes, etc. [López-Miras M. del M., Martin-Sánchez I., Yebra-Rodriguez A., Romero-Noguera J., Bolivar-Galiano F., Ettenauer J., et al. PLOS One. 2013, 8, e80198 doi:10.1371/journal.pone.0080198; 52. Sterflinger K., Pinzari F. Environ Microbiol. 2012, 14, 559-566. doi:10.1111/j. 1462-2920.2011.02584.x; Garg KL, Jain KK, Mishra AK Sci Total Environ. 1995, 167, 255-271. doi:10.1016/0048-9697(95)04587-Q; Li Q., Zhang B., He Z., Yang X. PLoS One. 2016, 11, e0163287. doi:10.1371/journal.pone.0163287; Gorbushina AA, Heyrman J., Dornieden T., Gonzalez-Delvalle M., Krumbein WE, Laiz L. Int Biodeterior Biodegrad. 2004, doi:10.1016/j.ibiod.2003.07.003]. Traditional antiseptics used for antifungal treatment in the restoration and conservation of tempera paintings are used with a number of limitations; only a small number of antimycotic agents have been tested for their compatibility with historical materials, and a small number of studies have been conducted on the long-term effects of biocides, such as possible color changes or the formation of degradation products [Zhgun, A.A.; Avdanina, D.A.; Shagdarova, V.T.; Troyan, E.V.; Nuraeva, GK; Potapov, MP; Il'ina, Shitov, M.V.; Varlamov, VP Search for Efficient Chitosan-Based Fungicides to Protect the 15 ^th -16 ^th Centuries Tempera Painting in Exhibits from the State Tretyakov Gallery. Microbiology 2020, 89, 750-755, doi:10.1134/S0026261720060193]. It is known that microorganisms are able to grow effectively on a wide variety of substrates used in tempera painting (temperas, plasticizers, varnishes, adhesives), and the best medium for fungal growth was the variants of the tempera paints themselves [Zhgun AA, Avdanina DA, Simonenko NP, Volkov IA , Ivanov VV. Detection of biodeterioration on materials used in tempera painting. Znan misel J. 2018; 1:7-15; Zhgun A. et al. PLoS ONE 2020, 15(4):e0230591]. As a result, biodegradation is the most important factor in damage to cultural heritage sites. Not surprisingly, a significant variety of compounds with fungicidal properties have already been developed to prevent it. However, most of them have some disadvantages.

Many fungicides used today to protect cultural heritage sites are organometallic compounds. For example, German researchers have shown that in terms of activity and duration of action, phenylmercuric acetate is superior to other compounds proposed for processing wall paintings: pentachlorophenol (PCP), benzimidazole derivatives, organotin compounds [Hirte WF, Glathe I., Thürmer L. Untersuchungen zum Schuts von Gemälden vor Befall mit Pilzen. Zbl. Microbiol., 1987, Bl. 142, N5. S. 377]. The disadvantage of mercury phenylacetate is its high toxicity and corrosivity towards non-ferrous metals. Another example of organometallic fungicides is TBTO (tributyltin oxide), which is used together with biocides from the class of organic compounds, in particular, together with quaternary ammonium compounds (QAC). TBTO and HOUR in 70% isopropyl alcohol were used to process ceiling paintings in Switzerland in a baroque church [Raschle P. Experience of combating molds during restoration of ceiling paintings in a Swiss baroque monastery church. Biodeterioration 5: ed., T.A. Oxley, S. Barry (International Biodeterioration Symposium 1981, 5th Aberdeen) 1983, Chichester N.Y., p.433]. However, the use of this combination is a temporary protection: until microclimatic conditions are created that exclude the possibility of biodamage to the painting. The disadvantage of TBTO and other organotin compounds is their high toxicity. This drawback is inherent in principle to most organometallic fungicides.

In Russia, biocides based on polyhexamethylene guanidine (polyhexamethylene guanidine chloride-methacid, polysept or polyhexamethylene guanidine phosphate-fogucid) have become widespread among restorers working with wall paintings belonging to art monuments. The disadvantage of these compounds is their good solubility in water. In conditions of moisture condensation or leaks, they cannot provide a long antimicrobial effect.

In US patent 5882731 B (B05D 3/00, A01N 25/02, A01N 29/00, A01N 31/02) an invention is presented for protecting external and internal surfaces from damage by microscopic fungi, mold. The invention is a film composition, which in various concentrations includes fillers from wax, fatty amines, amino silicones, surfactants and an aqueous solvent, and the active substance is a fungicide. The following substances can act as a fungicide: 2-(thiocyanomethylthio)benzothiazole; 3-iodine-2-propynyl-butylcarbamate; 2,4,5,6-tetrachloroisophthalonitrile; 2-(4-thiazolyl)benzimidazole; 2-N-octyl-4-isothiazolinone-3; n-tolyldiiodomethylsulfone, as well as a mixture of these substances in various proportions. Surfaces are recommended to be treated with this composition preventively by applying a thin film. The chemicals proposed in the patent are effective, but their disadvantage is their high toxicity.

In the invention SU 992241 A1 (IPC B44D 7/00, C07D 263/56), it is proposed to use the antiseptic drug 1-(2-benzoxazolyl)-3,3,3-trifluoroacetone in an aqueous-alcoholic or aqueous-acetone solution to protect works of fine art in fish glue. Treatment of tempera paints with 1% water-acetone solution or oil paints with 1% water-alcohol solution protects the paint coating from cracking, peeling and discoloration even after 30 days of exposure to sunlight at room temperature, t .e. the drug is neutral with respect to fine art materials. The invention notes that the proposed compound has a much greater bactericidal activity in comparison with the available traditional antiseptics, such as catamine AB, catapine and sodium pentachlorophenolate [Voronina L.I. Disinfection of easel oil and tempera painting with quaternary ammonium salts. Collection. Restoration, research, storage of easel paintings. Issue. 1, M., 1979]. However, the proposed drug was tested exclusively against bacteria of the genus Bacillus isolated from fish glue protected by a standard antiseptic used in restoration practice. Testing of 1-(2-benzoxazolyl)-3,3,3-trifluoroacetone has not been carried out on a wide range of prokaryotic cultures and, moreover, has not been tested on mold filamentous fungi that create the microbe of a particular museum.

Among the promising classes of biologically active compounds, attention should be paid to nucleosides and their derivatives. The antimycotic activity of nucleosides in relation to objects of cultural heritage has not been studied until recently. Recently, there have been reports of several groups of modified nucleosides that have demonstrated significant antimycotic activity against pathogens of fungal infections in humans [Serpi M, Ferrari V, Pertusati F. Nucleoside Derived Antibiotics to Fight Microbial Drug Resistance: New Utilities for an Established Class of Drugs? J Med Chem. 2016;59: 10343-10382; Niu G, Zheng J, Tan H. Biosynthesis and combinatorial biosynthesis of antifungal nucleoside antibiotics. Sci China Life Sci. 2017; 60: 939-947]. The antimycotic activity of nucleosides, especially N ⁴ -modified nucleosides, leading to inhibition of the growth of fungi biodestructors of cultural heritage objects, has not yet been identified.

Disclosure of the essence of the invention

The purpose of this invention is to obtain new N ⁴ -modified 5-methyl-2'-deoxycytidines containing in its composition an extended (with a carbon chain length of C ₁₀ -C ₁₂ ) alkyl substituent that inhibits the growth of filamentous fungi. The introduction of extended alkyl substituents into the nucleoside molecule leads to an increase in hydrophobicity and, as a consequence, reduces the water solubility of the target compounds.

To achieve this goal, methods such as:

- the introduction of protective groups (blocking of the hydroxyl groups of the nucleoside is carried out in order to prevent unwanted reactions during the synthesis, as well as to improve the mobility of intermediate compounds during chromatographic separation, which facilitates their purification);

- method of Divakar and Rice (introduction of alkyl substituents at the N ⁴ position of the nucleoside);

- reductive amination (reduction of the azido group to the amino group with simultaneous condensation with aldehyde;

- deblocking of protective groups (if necessary).

The next point in the implementation of the invention is to check the antimycotic activity of the obtained compounds, for this the tested derivative is added to a solid nutrient medium, on which strains of filamentous fungi are then sown, isolated from the exhibits and surfaces of the halls of Ancient Russia Painting of the Tretyakov Gallery.

Hereinafter the invention will be described in more detail with reference to the figures and examples, which are provided solely for the purpose of illustrating and explaining the essence of the claimed invention, but which are not intended to limit the scope of the claims.

Brief description of figures and tables

Fig. 1. Synthesis of N ⁴ -modified 5-methyl-2'-deoxycytidines (1-1 - 1-7). Reaction conditions: i) acetic anhydride, pyridine, +37°C, 20 h; ii) 1,2,4-triazole, 2-chlorophenyl dichlorophosphate, pyridine, +20°С, 20 h; iii) R-NH ₂ or RO-NH ₂ , dioxane, +20°C, 20 h; iv) 25% NH ₃ /H ₂ O, dioxane, +20°C, 20 h.

Fig. 2. Synthesis of 3'-substituted N ⁴ -alkyl-5-methyl-2',3'-dideoxycytidines (1-8 - 1-20). Reaction conditions: i) TBDMSCl, pyridine, +37°С, 20 h; ii) 1,2,4-triazole, 2-chlorophenyl dichlorophosphate, pyridine, +20°С, 20 h; iii) R-NH ₂ , dioxane, +20°C, 20 h; iv) Bu ₄ NF⋅3H ₂ O, dioxane, 20 h; v) 1: Ph ₃ P, dioxane, +20°C, 20 h; 2: 25% NH ₃ /H ₂ O, dioxane, +20°C, 20 h; vi) Ac ₂ O, pyridine, +20°C, 20 h; vii) 1: CH ₃ CHO, EtOH, 5° C., 2 h; 2: NaBH ₄ , +20°С, 20 h; viii) 1: CH ₃ CHO, EtOH, 5° C., 2 h; 2: NaBH ₃ (CN), +20°С, 20 h; ix) 1: CH ₂ O, MeOH, +20°C, 2 h; 2: NaBH ₃ (CN), +20°С, 20 h.

Fig. 3. Synthesis of 3'-triethylene glycol derivatives of N ⁴ -alkyl-5-methyl-2',3'-dideoxycytidines (1-21, 1-22). Reaction conditions: i) acetic anhydride, pyridine, +37°C, 20 h; ii) CDI, DMF, +37°C, 48 h; iii) triethylene glycol, dioxane, +37°С, 48 h; iv) TBDMS-Cl, pyridine, +20°С, 20 h; v) 1,2,4-triazole, 2-chlorophenyl dichlorophosphate, pyridine, +20°C, 20 h; vi) R-NH ₂ , dioxane, +20°C, 20 h; vii) Bu ₄ NF⋅3H ₂ O, dioxane, 20 h.

Fig. Fig. 4. Growth of various strains of filamentous fungi on Czapek-Dox agar medium with the addition of N ⁴ -modified 5-methyl-2'-deoxycytidines at a concentration of 0.7 mM, and also without addition (control) 30 days after inoculation.

Fig. Fig. 5. Dynamics of growth inhibition of strains of filamentous fungi isolated from the halls and works of art of the State Tretyakov Gallery by compounds 1-1-1-3, 1-21, and 5FC on an analytical medium added at concentrations of 0.5 mM and 3 mM. Data are given for 6, 12, 24, 30, 42 and 48 days after inoculation.

Fig. 6. The degree of sensitivity of strains of filamentous fungi to N ⁴ -modified 5-methyl-2'-deoxycytidines (1-1 - 1-3, 1-5, 1-6, 1-11 - 1-13, 1-15 - 1 -21) at a concentration of 0.7 mM and to 5FC.

Table 1. N ⁴ -modified 5-methyl-2'-deoxyribocytidines.

Implementation of the invention

Synthesis of compounds was carried out on the basis of commercially available thymidine and 3'-azido-3'-deoxythymidine. This made it possible to obtain a number of modified 5-methyl-2'-deoxyribocytidines containing an extended alkyl substituent in the N ⁴ position. To somewhat improve their extremely low solubility, in some cases, the 3' position was modified, namely, the replacement of the hydroxyl with amino, monoalkylamino, and dialkylamino groups, as well as the condensation of triethylene glycol through a carbonate linker. The list of synthesized compounds is given in Table 1 (see at the end of the description).

To obtain N ⁴ -alkyl derivatives of 5-methyl-2'-deoxyribocytidine, thymidine (2) was used, in which, first of all, two hydroxyl groups were protected with an acetyl group, for which thymidine was treated with acetic anhydride. Then, according to the method of [Divakar, KJ; Reese, S.V. J. Chem. Soc., Perkin Trans. 1982, 1, 1171] or its modifications [Lee, B.-Y.; Park, S. R.; Jeon, HB; Kim, RS; Tetrahedron Lett., 2006, 47, 5105], to the resulting compound 3 by successive treatments with 2-chlorophenyl dichlorophosphate with 1,2,4-triazole and then with the corresponding amine or O-alkylhydroxylamine in the presence of N,N-diisopropylethylamine (Fig. 1 ) introduced an extended n-alkyl substituent. After deprotection of the protective groups in compound 4 with an aqueous dioxane solution of ammonia, the target compounds (1-1 - 1-7) were isolated by column chromatography on silica gel, eluting with chloroform or ethyl acetate with an increasing concentration of ethanol.

5'-O-TBDMS-3'-azido-N ⁴ -alkyl-5-methyl-2',3'-dideoxycytidines (6-8) were obtained by a method analogous to the synthesis of compounds 1-1-1-7, starting from azidothymidine 5, and tert-butyldimethylsilyl group was used as a protective group (Fig. 2). Deprotection of the 5'-OTBDMS group with tetrabutylammonium fluoride trihydrate gave 3'-azido-N ⁴ -alkyl-5-methyl-2',3'-dideoxycytidines (1-8-1-10). The reduction of 5'-O-TBDMS-3'-azido-N ⁴ -alkyl-5-methyl-2',3'-dideoxycytidines (6-8) with triphenylphosphine made it possible to obtain key 5'-O-TBDMS-3'-amino- N ⁴ -alkyl-5-methyl-2',3'-dideoxycytidines (9-10), and subsequent deprotection of the protective group by the action of tetrabutylammonium fluoride trihydrate led to the target 3'-amino-N ⁴ -alkyl-5-methyl-2',3'-dideoxycytidinam (1-11 and 1-12). Reaction of 9-10 with either acetic anhydride or acetaldehyde and NaBH ₄ , followed by deprotection of the 5'-O-TBDMS group with tetrabutylammonium fluoride trihydrate, resulted in 3'-acetamido-(1-13 and 1-14) and 3' -ethylamino-N ⁴ -alkyl-5-methyl-2',3'-dideoxycytidine (1-15 and 1-16), respectively. Formaldehyde and acetaldehyde were used to obtain 3'-dialkylamino-N ⁴ -alkyl-5-methyl-2',3'-dideoxycytidines (1-17-1-20), and sodium cyanoborohydride (NaBH ₃ (CN) ).

The starting compound in the synthesis of triethylene glycol derivatives of N ⁴ -modified 5-methyl-2'-deoxycytidines was thymidine 2 (Fig. 3). At the first stage of the synthesis, selective protection of the hydroxyl group in the 5'-position of the carbohydrate residue was carried out by condensation of 2 with tert-butyldimethylsilyl chloride in pyridine upon cooling to +4°C. The 3'-O-Carbonyltriethylene glycol derivative of 5'-O-TBDMS-thymidine (11) was obtained by successive treatment of the protected thymidine with carbonyldiimidazole (CDI) in DMF and then, without isolation of the intermediate, with triethylene glycol in dioxane. Then, after extraction with water from chloroform-hexane, the organic layer was evaporated and treated with TBDMSC1 in pyridine to give the key compound (12). Treatment of (12) with 2-chlorophenyl dichlorophosphate and 1,2,4-triazole, followed by condensation with the corresponding amine (similar to the method described above) and deprotection of O-TBDMS protective groups by the action of tetrabutylammonium fluoride trihydrate, made it possible to obtain 3'-O-carbonyltriethylene glycol derivatives (1 -21 and 1-22), which were isolated by silica gel column chromatography, eluting with chloroform or ethyl acetate with increasing concentration of ethanol.

Antifungal activity of N ⁴ -modified 5-methyl-2'-deoxycytidines or 5-fluorocytosine (5FC), as a positive control, was evaluated against 11 strains of filamentous fungi, including five members of the Aspergillus family, two members of the Cladosporium family, and one member each of families Ulocladium, Simplicilium, Microascus and Penicillium. Compound efficacy was quantified by the percent inhibition of colony growth on Czapek-Dox agar medium (CDA) supplemented with N4-modified 5-methyl-2'-deoxycytidines or ^5FC compared to growth on control medium (no additives). The tested strains of filamentous fungi were isolated from the exhibits and surfaces of the halls of the Paintings of Ancient Russia (halls 56, 57 and 61) of the main historical building of the Tretyakov Gallery (Lavrushinsky per., 10, Moscow), namely: strain Aspergillus versicolor STG-25G (SRX7729174; MK260015. 1), Ulocladium sp.AAZ-2020a STG-36 (SRX7729176; MW590700) - from the icon "Militant Church" (1550s), Cladosporium halotolerans STG-52B (SRX7729178; MK258720.1) - from a bust fragment of the statue "Holy Great Martyr George the Victorious" (1464, Lime stone, tempera), Aspergillus creber STG-57 (SRX7729180; MK266993.1) - from the icon "The Holy Great Martyr Demetrius of Thessalonica" (16th century), Aspergillus versicolor STG-86 (SRX7729182; MK262781.1) , Aspergillus creber STG-93W (SRX7729186; MW575292), Cladosporium parahalotolerans STG-93B (SRX7729188; MK262909.1), Simplicillium lamellicola (STG-96 (SRX7729190; MK262921.1) - from the surfaces of room 61, Microgascus paisii ( SRX7729192; MW591474) - in room 57, Aspergillus protube rus STG-106 (SRX7729194; MK268342.1) and Penicillium chrysogenum STG-117 (MW556011.1) - in room 56.

The results obtained clearly demonstrate the antimycotic activity for most of the obtained compounds added at a concentration of 0.7 mm (Fig. 4). Compounds 1-12, 1-16 and 1-20 showed complete inhibition of growth of all fungal strains tested after 60 days of cultivation on analytical grade at 26°C. The addition of compounds 1-11, 1-15 and 1-19 resulted in complete suppression of the growth of most microorganisms, except for S. lamellicola (STG-96) and P. chrysogenum (STG-117), which are characterized by fast-growing colonies resistant to a wide range of antiseptics. Compounds 1-17 and 1-18 showed incomplete growth inhibition of strains STG-96 and STG-117. These compounds also failed to completely suppress the growth of some Aspergillus. Thus, strains STG-25G and STG-57 showed moderate sensitivity against 1-17, and strain STG-106 showed moderate sensitivity against both 1-17 and 1-18. An interesting resistance spectrum was found for compound 1-3. It completely suppresses the fast growing strains STG-96 and STG-117, but has only a partial effect on Aspergillus (strains STG-25G, STG-57, STG-86, STG-93W and STG-106). It is possible that the replacement of the amino group (or its alkyl derivatives) with a hydroxyl group in the 3'-position of the carbohydrate residue somewhat changes the mechanism of fungicidal action, which is reflected in the sensitivity of various systematic groups of fungi to these compounds.

It is also possible to trace several characteristic dependences in the series of synthesized compounds. The sensitivity of the studied strains of fungi to compounds with a hydroxyl group in the 3'-position of the carbohydrate residue increases in the order 1-1 - 1-2 - 1-3. In other words, increasing the length of the alkyl substituent from eight to twelve carbon atoms leads to an improvement in inhibitory activity. This effect is especially pronounced in the case of compounds containing an amino group in the 3'-position of the carbohydrate residue: in all cases, the presence of dodecyl in position N ⁴ led to a markedly greater inhibitory activity compared to decyl. The introduction of an azide or acetamide group into the 3'-position of the carbohydrate residue leads to almost complete loss of the fungicidal effect of the nucleoside at the tested concentrations.

Replacing the decyl substituent in position N ⁴ (compound 1-2) with decyloxy (compound 1-5) leads to a decrease in the activity of the compound (the level of antimycotic activity drops to the level of compound 1-1, with the octyl radical in the corresponding position). An increase in the length of the alkyloxy substituent in the same position by one methylene group (compound 1-6) slightly increases the activity compared to 1-5 (in this case, the undecyloxy radical in position N ⁴ leads to approximately the same activity as the decyl radical in that same position (Fig. 6)).

Thus, for the studied strains of fungi, the most effective were compounds containing a dodecyl radical in position N ⁴ and an amino group in the 3'-position of the carbohydrate residue (against all strains). Replacing the amino group with a hydroxyl group results in the loss of inhibitory activity against aspergillus.

Commercial reagents were purchased from Acros, Aldrich and Fluka. All solvents were purified according to well known methods. Column chromatography was performed on silica gel 40–63 μm in diameter (Acros), thin layer chromatography was performed on silica gel 60 F ₂₅₄ plates (Merck, Germany). NMR spectra were recorded on an AMX III-400 spectrometer (Bruker BioSpin, GmbH, Germany) with an operating frequency of 400 MHz for ¹ H NMR (Me ₄ Si as an internal standard for organic solvents) and 101 MHz for ¹³ C NMR (with suppression of C-H correlation) or on an AM-300 spectrometer (Bruker BioSpin, GmbH, Germany) with an operating frequency of 300 MHz for ¹ H NMR (Me ₄ Si as an internal standard for organic solvents) and 75 MHz for ¹³ C NMR (with suppression of CH correlation ). UV spectra were recorded using Perkin Elmer lambda 25 (Perkin Elmer, USA) in methanol. High resolution mass spectra were recorded on a Bruker Daltonics micrOTOF-Q II mass spectrometer (Bruker-MS, GmbH, Germany) with electrospray ionization. The measurements were carried out in the positive ion mode in accordance with the previously used conditions.

The following are examples illustrating the present invention. Variants and modifications of the invention, which can be reproduced without departing from the general concept of the present invention and without involving one's own inventive activity, will also be included in the scope of the present invention.

Example 1 Synthesis of N ⁴ -octyl-5-methyl-2'-deoxycytidine (1-1)

Acetic anhydride (118 μl, 1.25 mmol) was added to a solution of thymidine 2 (121 mg, 0.5 mmol) in absolute pyridine and left at +37°С for 20 h. The reaction mixture was evaporated, the solid residue was dissolved in a minimum volume of ethanol and left at + 4°C for 48 h. The resulting crystals were filtered off, washed with ethanol cooled to -20°C, then left in a desiccator over paraffin at low pressure for 48 h. To compound 3 thus obtained, dissolved in absolute pyridine and cooled to 0° C, 1,2,4-triazole (200 mg, 3 mmol) and 2-chlorophenyl dichlorophosphate (188 mg, 0.77 mmol) were added. The mixture was left for 20 h at room temperature, then evaporated, the residue was partitioned between chloroform and 0.5 M sodium bicarbonate, the organic layer was washed with water, dried over Na ₂ SO ₄ , evaporated, dissolved in anhydrous dioxane, cooled to 0°C, and 1- octylamine (165 µl, 1 mmol) and N,N-diisopropylethylamine (175 µl, 1 mmol). The mixture was left for 20 h at room temperature, then 3 ml of 25% aqueous ammonia was added and left for 40 h at room temperature. The reaction mixture was evaporated. The resulting solid mixture of substances was separated on a column (2×15 cm) with silica gel, eluting with a chloroform:ethanol system in a ratio of 9:1 (v/v). Target product 1-1 was obtained in the amount of 138 mg (78%) in the form of solid white crystals. UV: λ _max 273 nm. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 0.84 (3H, t, J=6.8 Hz, -CH ₂ - C H ₃ ), 1.21-1.30 (10H, m, -NH-(CH ₂ ) ₂ - ( CH ₂ ) ₅ -), 1.46-1.55 (2Н, m, -NH-CH ₂ - CH ₂ - ), 1.84 (3Н, s, 5-CH ₃ ), 1.95 (1Н, ddd, J=13.3, 7.7 , 6.0 Hz, 2'-Ha), 2.06 (1Н, ddd, J=13.1, 6.0, 3.2 Hz, 2'-Hb), 3.25-3.31 (2Н, m, -NH- CH ₂ -), 3.54 (1H , ddd, J=12.0, 5.3, 3.9 Hz, 5'-Ha), 3.59 (1H, ddd, J=11.8, 5.5, 3.8 Hz, 5'-Hb), 3.75 (1Н, td, J=3.9, 3.3 Hz, 4'-H), 4.21 (1H, ddt, J=6.0, 4.3, 3.3 Hz, 3'-H), 4.96 (1H t, J=5.3 Hz, 5'-OH), 5.15 (1H, d , J=4.3 Hz, 3'-OH), 6.17 (1Н, dd, J=7.6, 6.0 Hz, 1'-H), 7.10 (1Н, t, J=5.7 Hz, N ⁴ -H), 7.56 ( 1H, s, 6-H). ¹³ C NMR (101 MHz, DMSO-d ₆ ) δ 13.05 (5- CH ₃ ), 13.84 (-CH ₂ -CH ₃ ), 22.01, 26.43, 28.54, 28.61, 28.76, 31.19 (-NH-CH ₂ -( CH ₂ ) ₆ -). 40.05 (2'-C), 40.17 (-NH- CH ₂ -), 61.39 (5'-C), 70.42 (3'-C), 84.56 (l'-C), 87.03 (4'-C), 101.63 (5-C), 137.09 (6-C), 155.09 (2-C), 162.61 (4-C). HRMS (ESI) calculated for C ₁₈ H ₃₁ N ₃ O ₄ , m/z: 354.2387 [M+H]+, found 354.2383.

Example 2 Synthesis of N ⁴ -decyl-5-methyl-2'-deoxycytidine (1-2)

Obtained according to the method described in Example 1, from 2 (121 mg, 0.5 mmol) and 1-decylamine (200 μl, 1 mmol). Yield 147 mg (77%) as solid white crystals. UV: λ _max 273 nm. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 0.84 (3H, t, J=6.8 Hz, -CH ₂ -CH ₃ ), 1.21-1.28 (14H, m, -NH-(CH ₂ ) ₂ -( CH ₂ ) ₇ -), 1.45-1.55 (2Н, m, -NH-CH ₂ - CH ₂ -), 1.84 (3Н, d, J=1.0 Hz, 5-CH ₃ ), 1.95 (1H, ddd, J =13.3, 7.8, 6.1 Hz, 2'-Ha), 2.06 (1H, ddd, J=13.1, 6.0, 3.2 Hz, 2'-Hb), 3.25-3.31 (2H, m, -NH- CH ₂ -) , 3.54 (1H, ddd, J=11.7, 5.3, 4.0 Hz, 5'-Ha), 3.59 (1Н, ddd, J=11.7, 5.3, 3.8 Hz, 5'-Hb), 3.75 (1Н, ddd, J =4.2, 3.7, 3.1 Hz, 4'-H), 4.21 (1H, ddt, J=6.0, 4.2, 3.2 Hz, 3'-H), 4.96 (1H, t, J=5.3 Hz, 5'-OH ), 5.16 (1H, d, J=4.2 Hz, 3'-OH), 6.17 (1H, dd, J=7.6, 5.9 Hz, 1'-H), 7.09 (1H, t, J=5.7 Hz, N ⁴ -H), 7.56 (1H, d, J=1.2 Hz, 6-H). ¹³ C NMR (101 MHz, DMSO-d ₆ ) δ 13.08 (5- CH ₃ ), 13.87 (-CH ₂ -CH ₃ ) , 22.05, 26.45, 28.57, 28.67, 28.83, 28.94, 28.99, 31.26 CH ₂ - (CH ₂ ) ₈ -), 40.14 (2'-C), 40.20 (-NH- CH ₂ -), 61.42 (5'-C), 70.45 (3'-C), 84.59 (1'- C), 87.05 (4'-C), 101.66 (5-C), 137.11 (6-C), 155.12 (2-C), 162.64 (4-C). HRMS (ESI) calculated for C ₂₀ H ₃₅ N ₃ O ₄ , m/z: 382.2700 [M+H]+, found 382.2703.

Example 3 Synthesis of N ⁴ -dodecyl-5-methyl-2'-deoxycytidine (1-3)

Obtained according to the method described in Example 1, from 2 (121 mg, 0.5 mmol) mg and 1-dodecylamine (185 mg, 1 mmol). Yield 147 mg (77%) as solid white crystals. UV: λ _max 273 nm. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 0.86 (3H, t, J=6.8 Hz, -CH ₂ - CH ₃ ), 1.23 -1.28 (18H, m, -NH-(CH ₂ ) ₂ -( CH ₂ ) ₉ -), 1.47-1.56 (2H, m, -NH-CH ₂ - CH ₂ - ), 1.84 (3H, d, J=. 1.0 Hz, 5-CH ₃ ), 1.95 (1H, ddd, J=13.2, 7.8, 6.0 Hz, 2'-Ha), 2.06 (1H, ddd, J=13.1, 6.0, 3.2 Hz, 2'-Hb), 3.19-3.32 (2H, m, -NH-CH ₂ - ), 3.53 (1H, ddd, J=11.8, 5.3, 4.2 Hz, 5'-Hb), 3.59 (1H, ddd, J=11.7, 5.3, 3.9 Hz, 5'-Ha), 3.75 (1H, ddd, J=4.1, 3.6, 3.0 Hz, 4'-H), 4.21 (1H, dddd, J=6.0, 4.2, 3.2, 2.8 Hz, 3'-H), 4.97 (1H, t, J=5.3 Hz, 5 '-OH), 5.16 (1H, d, J=4.2 Hz, 3'-OH), 6.18 (1H, dd, J=7.6, 6.0 Hz, 1'-H), 7.10 (1H, t, J=5.7 Hz, N ⁴ -H), 7.56 (1H, d, J=1.2 Hz, 6-H). ¹³ C NMR (75 MHz, DMSO-d ₆ ) δ 13.11 (5-CH ₃ ), 13.90 (-C ₁₁ H ₂₂ - CH ₃ ), 22.06, 26.45, 28.57, 28.68, 28.84, 29.00, 29.03, 31.27 (- NH-CH ₂ - (CH ₂ ) ₁₀ -). 40.11 (2'-C), 40.24 (-NH-CH ₂ -), 61.40 (5'-C), 70.43 (3'-C), 84.58 (1'-C), 87.07 (4'-C), 101.65 (5-C), 137.18 (6-C), 154.93 (2-C), 162.50 (4-C). HRMS (ESI) calculated for C ₂₂ H ₃₉ N ₃ O ₄ , m/z: 410.3019 [M+H]+, found 410.3022.

Example 4 Synthesis of N ⁴ -octyloxy-5-methyl-2'-deoxycytidine (1-4)

Obtained according to the method described in Example 1, from 2 (121 mg, 0.5 mmol) and O-octylhydroxylamine (145 mg, 1 mmol). Yield 138 mg (78%) as solid white crystals. UV: λ _max 276 nm. ¹ H NMR (DMCO-d ₆ ): δ 0.84 (3H, t, J=6.8 Hz, -(CH ₂ ) ₅ CH ₃ ), 1.25-1.48 (10H, m, -CH ₂ CH ₂ ( CH ₂ ) ₅ CH ₃ ), 1.50 (2Н, m, -CH ₂ CH ₂ (CH ₂ ) ₅ CH ₃ ), 1.84 (3Н, s, 5-CH ₃ ), 1.93-1.99 (1Н, m, 2'-Нa), 2.03-2.08 (1H, m, 2'-Hb), 3.27 (2H, m, -CH ₂ CH ₂ (CH ₂ ) ₅ CH ₃ ), 3.54-3.56 (2H, m, 5'-H), 3.76 ( 1H, m, 4'-H), 3.85 (2H, m, O-CH ₂ ), 4.19-4.21 (1H, m, 3'-CH), 4.96 (1H, t, J=5.3 Hz, 5'- OH), 5.15 (1H, d, J=4.2 Hz, 3'-OH), 6.18 (1H, t, J=7 Hz, 1'-H), 7.56 (1H, s, 6-CH), 9.48 ( 1H, s, NH). ¹³ C NMR (DMSO-d ₆ ): δ 13.05 (5-CH ₃ ), 13.83 (-(CH ₂ ) ₇ CH ₃ ), 22.0-31.19 (-C ₇ H ₁₄ ), 40.17 (2'-C), 61.38 (5'-C), 70.31 (3'-C), 84.55 (l'-C), 87.01 (4'-C), 101.61 (5-C), 137.07 (6-C), 155.07 (2- C), 162.59 (4-C). HRMS (ESI) calculated for C ₁₈ H ₃₁ N ₃ O ₅ , m/z: 370.2342 [M+H]+, found 370.2330.

Example 5 Synthesis of N ⁴ -decyloxy-5-methyl-2'-deoxycytidine (1-5)

Obtained according to the method described in Example 1, from 2 (121 mg, 0.5 mmol) and O-decylhydroxylamine (173 mg, 1 mmol). Yield 161 mg (77%) as solid white crystals. UV: λ _max 277 nm. ¹ H NMR (DMSO-d ₆ ): δ 0.81 (3H, t, J=6.8 Hz, -(CH ₂ ) ₉ CH ₃ ), 1.21 (14H, m, -CH ₂ CH ₂ ( CH ₂ ) ₇ CH ₃ 1.52 (2H, m, -CH ₂ CH ₂ (CH ₂ ) ₇ CH ₃ ), 1.57 (3H, s, 5-CH ₃ ), 1.92-2.08 (2H, m, 2'-H), 3.51-3.54 (2H, m, 5'-H), 3.76 (1H, m, 4'-H), 3.85 (2H, m, O- CH ₂ (C ₉ H ₁₈ )-), 4.18-4.20 (1H, m, 3'-H), 4.93 (1H, t, J=5.3 Hz, 5'-OH), 5.15 (1H, d, J=4.2 Hz, 3'-OH), 6.15 (1H, t, J=7 Hz , _1' -CH), _7.93 (1H, s, ⁶ -H), 9.47 (1H, s, NH). CH ₂ ) ₉ CH ₃ ), 22.02-31.23 (-C ₉ H ₂₈ ), 39.29 (2'-C), 61.38 (5'-C), 70.42 (3'-C), 84.78 (1'-C) , 87.1 (4'-C), 94.62 (5-C), 139.55 (6-C), 155.1 (2-C), 163.22 (4-C) HRMS (ESI) calculated for C ₂₀ H ₃₅ N ₃ O ₅ , m/z: 398.2655 [M+H]+, found 398.2659.

Example 6 Synthesis of N ⁴ -undecyloxy-5-methyl-2'-deoxycytidine (1-6)

Obtained according to the method described in Example 1, from 2 (121 mg, 0.5 mmol) and O-undecylhydroxylamine (187 mg, 1 mmol). Yield 161 mg (78%) as solid white crystals. UV: λ _max 277 nm. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 0.85 (3H, t, J=6.8 Hz, -CH ₂ - CH ₃ ), 1.21-1.28 (16H, m, -NH-(CH ₂ ) ₂ -( CH ₂ ) ₈ ), 1.84 (3Н, d, J=1.0 Hz, 5-CH ₃ ), 1.95 (1Н, ddd, J=13.3, 7.8, 6.1 Hz, 2'-Ha), 2.06 (1Н, ddd, J=13.1, 6.0, 3.2 Hz, 2'-Hb), 3.54 (1H, ddd, J=11.7, 5.3, 4.0 Hz, 5'-Ha), 3.59 (1H, ddd, J=11.7, 5.3, 3.8 Hz , 5'-Hb), 3.75 (1H, ddd, J=4.2, 3.7, 3.1 Hz, 4'-H), 3.86 (2H, m, -NH-O- CH ₂ -), 4.21 (1H, ddt, J=6.0, 4.2, 3.2 Hz, 3'-H), 4.96 (1H, t, J=5.3 Hz, 5'-OH), 5.16 (1H, d, J=4.2 Hz, 3'-OH), 6.17 (1H, dd, J=7.6, 5.9 Hz, 1'-H), 7.56 (1H, d, J=1.2 Hz, 6-H), 9.46 (1H, s, NH). ¹³ C NMR (101 MHz, DMSO-d ₆ ) δ 13.08 (-CH ₂ -CH ₃ ), 13.87 (5-CH ₃ ), 22.05, 26.45, 28.57, 28.67, 28.83, 28.94, 28.99, 31.26 (-NH- CH ₂ -( CH ₂ ) ₉ -). 40.14 (2'-C), 40.20 (-NH- CH ₂ -), 61.42 (5'-C), 70.45 (3'-C), 84.59 (1'-C), 87.05 (4'-C), 101.66 (5-C), 137.11 (6-C), 155.12 (2-C), 162.64 (4-C). HRMS (ESI) calculated for C ₂₁ H ₃₇ N ₃ O ₅ , m/z: 412.2812 [M+H]+, found 412.2814.

Example 7 Synthesis of N ⁴ -dodecyloxy-5-methyl-2'-deoxycytidine (1-7)

Obtained according to the method described in Example 1, from 2 (121 mg, 0.5 mmol) and O-dodecylhydroxylamine (201 mg, 1 mmol). Yield 154 mg (75%) as white solid crystals. UV: λ _max 273 nm. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 0.81 (3H, t, J=6.8 Hz, -CH ₂ -CH ₃ ), 1.19 (18H, m, -NH-(CH ₂ ) ₂ - (CH ₂ ) _9- ). 1.49-1.58 (2Н, m, -NH-CH ₂ -CH ₂ -), 1.85 (3Н, d, J=1.0 Hz, 5-CH ₃ ), 1.95 (1H, ddd, J=13.2, 7.8, 6.0 Hz , 2'-Ha), 2.06 (1H, ddd, J=13.1, 6.0, 3.2 Hz, 2'-Hb), 3.19-3.32 (2H, m, -NH- CH ₂ -), 3.53 (1H, ddd, J=11.8, 5.3, 4.2 Hz, 5'-Hb), 3.59 (1H, ddd, J=11.7, 5.3, 3.9 Hz, 5'-Ha), 3.75 (1H, ddd, J=4.1, 3.6, 3.0 Hz , 4'-H). 3.85 (2H, -NH-O- CH ₂ -), 4.21 (1H, dddd, J=6.0, 4.2, 3.2, 2.8 Hz, 3'-H), 4.97 (1H, t, J=5.3 Hz, 5' -OH), 5.16 (1H, d, J=4.2 Hz, 3'-OH), 6.11 (1H, dd, J=7.6, 6.0 Hz, 1'-H), 6.94 (1H, d, J=1.2 Hz , 6-H), 9.46 (1H, s, NH). ¹³ C NMR (75 MHz, DMSO-d ₆ ) δ 13.11 (-CH ₂ -CH ₃ ) , 13.90 (5- CH ₃ ), 22.06, 26.45, 28.57, 28.68, 28.84, 29.00, 29.03, 31.27 (-NH- CH ₂ - (CH ₂ ) ₁₀ -). 40.11 (2'-C), 40.24 (-NH- CH ₂ -), 61.40 (5'-C), 70.43 (3'-C), 84.58 (1'-C), 87.07 (4'-C), 101.65 (5-C), 137.18 (6-C), 154.93 (2-C), 162.50 (4-C). HRMS (ESI) calculated for C ₂₂ H ₃₉ N ₃ O ₅ , m/z: 426.2968 [M+H]+, found 426.2969.

Example 8 Synthesis of 3'-azido-N ⁴ -octyl-5-methyl-2',3'-dideoxycytidine (1-8)

To a solution of azidothymidine 5 (134 mg, 0.5 mmol) in absolute pyridine was added tert-butyldimethylsilyl chloride (98 mg, 0.65 mmol) and left at +37°C for 20 h, after which the resulting solution was evaporated, the residue was partitioned between ethyl acetate and 0.5 M bicarbonate sodium. The organic fraction was collected, dried over Na ₂ SO ₄ and evaporated. 1,2,4-triazole (345 mg, 5 mmol) and 2-chlorophenyl dichlorophosphate (165 μl, 1 mmol) were added to the obtained solid residue and left at room temperature for 20 h. Then the reaction mixture was evaporated, the solid residue was partitioned between ethyl acetate and 0.5 M sodium bicarbonate. The organic phase was dried over Na ₂ SO ₄ and then evaporated. 1-octylamine (0.165 µl, 1 mmol) and N,N-diisopropylethylamine (348 µl, 2 mmol) were added to the solid residue. The reaction mixture was evaporated, the residue was partitioned between chloroform and 0.5 M sodium bicarbonate, the organic layer was washed with water, dried over Na ₂ SO ₄ and evaporated. Compound 6 was purified on a column (2×15 cm) with silica gel in the system ethyl acetate:hexane in a ratio of 1:1 (v/v). The resulting solution was evaporated, dissolved in dioxane, tetrabutylammonium fluoride trihydrate (205 mg, 0.65 mmol) was added, left for 20 h at room temperature, and then evaporated. The solid residue was purified on a column (2×15 cm) with silica gel. Product 1-8 was eluted with chloroform:ethanol (20:1). Yield 161 mg (85%) as solid white crystals. UV: λ _max 277 nm. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 0.85 (3H, t, J=7.0 Hz, -C ₇ H ₁₄ CH ₃ ), 1.25 (10H, m, -NH-(CH ₂ ) ₂ - C ₅ H ₁₀ - CH ₃ ), 1.51 (2Н, m, -NH-CH ₂ - CH ₂ -), 1.84 (3Н, d, J=0.6 Hz, 5-CH ₃ ), 2.24 (2Н, t, J=6.3 Hz, 2'-H), 3.28 (2H, m, -NH CH ₂ -), 3.58 (1H, ddd, J=11.8, 5.4, 4.1 Hz, 5'-Ha), 3.64 (1H, ddd, J= 11.8, 5.4, 4.1 Hz, 5'-Hb), 3.81 (1H, q, J=4.1 Hz, 4'-H), 4.34 (1H, td, J=6.3, 4.1 Hz, 3'-H), 5.16 (1H, t, J=5.4 Hz, 5'-OH), 6.10 (1H, t, J=6.5 Hz, 1'-H), 7.13 (1H, t, J=5.6 Hz, - NH CH ₂ -) , 7.54 (1H, m, 6-H). ¹³ C NMR (101 MHz, DMSO-d ₆ ) δ 13.05 (5-CH ₃ ), 13.88 (-C ₇ H ₁₄ CH ₃ ), 22.04, 26.44, 28.54, 28.62, 28.77, 31.21 (-NHCH ₂ - C ₆ H ₁₂ -CH ₃ ), 36.74 (-NHCH ₂ -), 40.20 (2'-C), 60.37 (3'-C), 60.95 (5'-C), 83.86 (1'-C), 84.25 (4 '-C), 101.83 (5-C), 137.04 (6-C), 154.92 (2-C), 162.69 (4-C). HRMS (ESI) calculated for C ₁₈ H ₃₀ N ₆ O ₃ , m/z: 401.2277 [M+Na]+, found 401.2272.

Example 9 Synthesis of 3'-azido-N ⁴ -decyl-5-methyl-2',3'-dideoxycytidine (1-9)

Obtained according to the method described in Example 8, from 5 (134 mg, 0.5 mmol) and 1-decylamine (200 μl, 1 mmol). Yield 169 mg (83%) as solid white crystals. UV: λ _max 276 nm. ¹ H NMR (DMSO-d ₆ , 400 MHz) δ 0.85 (3H, t, J=6.8 Hz, -C ₉ H ₁₈ - CH ₃ ), 1.21-1.29 (14H, m, -NH-(CH ₂ ) ₂ - C ₇ H ₁₄ - ), 1.45-1.56 (2Н, m, -NH-CH ₂ - CH ₂ -), 1.84 (3Н, s, 5-CH ₃ ), 2.24 (2Н, t, J=6.3 Hz, H-2'), 3.23-3.30 (2H, m, -NH- CH ₂ -), 3.58 (1H, ddd, J=11.8,5.4, 4.1 Hz, H-5'a), 3.64 (1H, ddd, J=11.8, 5.4, 4.1 Hz, H-5'b), 3.81 (1H, q, J=4.1 Hz, H-4'), 4.34 (1H, td, J=6.3, 4.1 Hz, H-3' ), 5.16 (1H, t, J=5.4 Hz, -OH), 6.10 (1H, t, J=6.5 Hz, H-1'), 7.12 (1Н, t, J=5.6 Hz, HN ⁴ ), 7.51 -7.58 (1H, m, H-6). ¹³ С NMR (DMSO-d ₆ , 101 MHz) δ 13.05 (5-CH ₃ ), 13.88 (-C ₉ H _{1 8} C H ₃ ), 22.04, 26.43, 28.65, 28.81, 28.92, 28.98, 31.25 (-NH -(CH ₂ ) ₂ - C ₇ H ₁₄ -), 28.54 (-NH- C H ₂ -CH ₂ -), 36.75 (C-2'), 40.19 (-NH- C H ₂ -), 60.37 (C -3'), 60.95 (C-5'), 83.86 (C-1'), 84.25 (C-4'), 101.83 (C-5), 137.04 (C-6), 154.92 (C-2), 162.69 (C-4). HRMS (ESI) calculated for C ₂₀ H ₃₄ N ₆ O ₃ , m/z: 429.2590 [M+Na]+, found 429.2599.

Example 10 Synthesis of 3'-azido-N ⁴ -dodecyl-5-methyl-2',3'-dideoxycytidine (1-10)

Obtained according to the method described in example 8, from 5 (134 mg, 0.5 mmol) and 1-dodecylamine (185 mg, 1 mmol). Yield 180 mg (83%) as solid white crystals. UV: λ _max 276 nm. ¹ H NMR (DMSO-d ₆ , 300 MHz) δ 0.86 (3H, t, J=6.7 Hz, -C ₁₁ H ₂₂ - CH ₃ ), 1.21-1.30 (18H, m, -NH-(CH ₂ ) ₂ - C ₉ H ₁₈ -), 1.42-1.60 (2Н, m, -NH-CH ₂ - CH ₂ -), 1.85 (3Н, d, J=0.8 Hz, 5-CH ₃ ), 2.25 (2Н, t, J=6.3 Hz, H-2'), 3.20-3.31 (2H, m, -NH-CH ₂ -), 3.59 (1H, ddd, J=11.9, 5.4, 4.1 Hz, H-5'b), 3.65 (1H, ddd, J=11.9, 5.4, 4.1 Hz, H-5'a), 3.82 (1H, q, J=4.4 Hz, H-4'), 4.35 (1H, td, J=6.3, 4.4 Hz , H-3'), 5.17 (1H, t, J=5.4 Hz, -OH), 6.10 (1H, t, J=6.5 Hz, H-1'), 7.14 (1H, t, J=5.6 Hz, HN ⁴ ), 7.51-7.58 (1H, m, H-6). ¹³ C NMR (DMSO-d ₆ , 75 MHz) δ 13.07 (5-CH ₃ ), 13.90 (-C ₁₁ H ₂₂ -CH ₃ ), 22.06, 26.44, 28.67, 28.83, 28.99, 31.26 (-NH-(CH ₂ ) ₂ - C ₉ H ₁₈ -), 28.55 (-NH-CH ₂ -CH ₂ -), 36.74 (-NH-CH ₂ -), 40.19 (C-2'), 60.36 (C-3'), 60.94 (С-5'), 83.85 (С-1'), 84.22 (С-4'), 101.81 (С-5), 137.04 (С-6), 154.90 (С-2), 162.68 (С-4 ). HRMS (ESI) calculated for C ₂₂ H ₃₈ N ₆ O ₃ , m/z: 457.2903 [M+Na]+, found 457.2902.

Example 11 Synthesis of 3'-amino-N ⁴ -decyl-5-methyl-2',3'-dideoxycytidine (1-11)

To a solution of azidothymidine 5 (134 mg, 0.5 mmol) in absolute pyridine was added tert-butyldimethylsilyl chloride (98 mg, 0.65 mmol) and left at +37°C for 20 h, after which the resulting solution was evaporated, the residue was partitioned between ethyl acetate and 0.5 M bicarbonate sodium. The organic fraction was collected, dried over Na ₂ SO ₄ and evaporated. 1,2,4-triazole (345 mg, 5 mmol) and 2-chlorophenyl dichlorophosphate (165 μl, 1 mmol) were added to the obtained solid residue and left at room temperature for 20 h. Then the reaction mixture was evaporated, the solid residue was partitioned between ethyl acetate and 0.5 M sodium bicarbonate. The organic phase was dried over Na ₂ SO ₄ and then evaporated. To the solid residue were added 1-decylamine (200 μl, 1 mmol) and N,N-diisopropylethylamine (348 μl, 2 mmol). The reaction mixture was evaporated, the residue was partitioned between chloroform and 0.5 M sodium bicarbonate, the organic layer was washed with water, dried over Na ₂ SO ₄ and evaporated. Compound 7 was purified on a column (2×15 cm) with silica gel in the system ethyl acetate:hexane in a ratio of 1:1 (v/v). The resulting solution was evaporated, dissolved in dioxane (5 ml), and triphenylphosphine (262 mg, 1 mmol) was added, after which it was kept for 20 h at room temperature, then 1.5 ml of a 25% aqueous solution of ammonia was added and left for 20 h at room temperature. The reaction mixture was evaporated, the product 9 was isolated on a silica gel column (2×15 cm) with a solvent mixture of chloroform-ethanol 9:1 (v/v). The resulting solution was evaporated, dissolved in dioxane, tetrabutylammonium fluoride trihydrate (205 mg, 0.65 mmol) was added, left for 20 h at room temperature, and then evaporated. The solid residue was purified on a column (2×15 cm) with silica gel. Product 1-11 was eluted with a solvent mixture of chloroform:methanol (3:2). Yield 143 mg (75%) as solid white crystals. UV: λ _max 277 nm. ¹ H NMR (DMSO-d ₆ , 300 MHz) δ 0.85 (3H, t, J=6.7 Hz, -C ₉ H ₁₈ CH ₃ ), 1.21-1.30 (14H, m, -NH-(CH ₂ ) ₂ - C ₇ H ₁₄ -), 1.45-1.56 (2Н, m, -NH-CH ₂ - CH ₂ -), 1.84 (3Н, d, J=0.8 Hz, 5-CH ₃ ), 1.92-2.08 (2Н, m , H-2'), 3.15-3.26 (2H, m, -NH-CH ₂ -), 3.41-3.46 (1H, m, H-3'), 3.50-3.56 (1H, m, H-4') , 3.56-3.63 (1H, m, H-5'a), 3.63-3.72 (1H, m, H-5'b), 6.07 (1H, t, J=5.8 Hz, H-1'), 7.06 ( 1Н, t, J=5.6 Hz, Н-N ⁴ ), 7.62-7.66 (1Н, m, Н-6). ¹³ C NMR (DMSO-d ₆ , 75 MHz) δ 13.15 (5-CH ₃ ), 13.95 (-C ₉ H ₁₈ CH ₃ ), 22.10, 26.50, 28.71, 28.88, 28.98, 29.04, 31.31 (-NH-( CH ₂ ) ₂ - C ₇ H ₁₄ -), 28.63 (-NH-CH ₂ - C H ₂ -), 40.23 (-NH-CH ₂ -), 41.04 (C-2'), 50.56 (C-3' ), 60.78 (С-5'), 84.15 (С-1'), 87.11 (С-4'), 101.32 (С-5), 137.30 (С-6), 155.12 (С-2), 162.70 (С -4). HRMS (ESI) calculated for C ₂₀ H ₃₆ N ₄ O ₃ , m/z: 381.2866 [M+H]+, found 381.2857.

Example 12 Synthesis of 3'-amino-N ⁴ -dodecyl-5-methyl-2',3'-dideoxycytidine (1-12)

Obtained according to the method described in Example 11, from 5 (134 mg, 0.5 mmol) and 1-dodecylamine (185 mg, 1 mmol) with a yield of 161 mg (79%) in the form of solid white crystals. UV: λ _max 277 nm. ¹ H NMR (DMSO-d ₆ , 300 MHz) δ 0.85 (2H, t, J=6.8 Hz, -C ₁₁ H ₂₂ - CH ₃ ), 1.20-1.30 (19H, m, -NH-(CH ₂ ) ₂ - C ₉ H ₁₈ -), 1.45-1.56 (2Н, m, -NH-CH ₂ - CH ₂ -), 1.85 (3Н, d, J=1.0 Hz, 5-CH ₃ ), 1.93-2.10 (2Н, m, H-2'), 3.24-3.33 (2H, m, -NH- CH ₂ -), 3.37-3.47 (1H, m, H-3'), 3.54-3.58 (1H, m, H-4' ), 3.58-3.63 (1H, m, H-5'a), 3.63-3.75 (1H, m, H-5'b), 6.09 (1H, dd, J=6.4, 5.3 Hz, H-1') , 7.09 (1Н, t, J=5.7 Hz, HN ⁴ ), 7.63 -7.68 (1H, m, Н-6). ¹³ C NMR (DMSO-d ₆ , 75 MHz) δ 13.11 (5-CH ₃ ), 13.87 (-C ₁₁ H ₂₂ -CH ₃ ), 22.06, 26.49, 28.69, 28.87, 29.01, 29.04, 31.27 (-NH- (CH ₂ ) ₂ - C ₉ H ₁₈ -), 28.60 (-NH-CH ₂ - C H ₂ -), 40.19 (-NH- C H ₂ -), 40.78 (C-2'), 50.50 (C- 3'), 60.73 (С-5'), 84.12 (С-1'), 86.88 (С-4'), 101.28 (С-5), 137.22 (С-6), 155.07 (С-2), 162.64 (S-4). HRMS (ESI) calculated for C ₂₂ H ₄₀ N ₄ O ₃ , m/z: 409.3179 [M+H]+, found 409.3188.

Example 13 Synthesis of 3'-acetamido-N ⁴ -decyl-5-methyl-2',3'-dideoxycytidine (1-13)

To a solution of azidothymidine 5 (134 mg, 0.5 mmol) in absolute pyridine was added tert-butyldimethylsilyl chloride (98 mg, 0.65 mmol) and left at +37°C for 20 h, after which the resulting solution was evaporated, the residue was partitioned between ethyl acetate and 0.5 M bicarbonate sodium. The organic fraction was collected, dried over Na ₂ SO ₄ and evaporated. 1,2,4-triazole (345 mg, 5 mmol) and 2-chlorophenyl dichlorophosphate (165 μl, 1 mmol) were added to the obtained solid residue and left at room temperature for 20 h. Then the reaction mixture was evaporated, the solid residue was partitioned between ethyl acetate and 0.5 M sodium bicarbonate. The organic phase was dried over Na ₂ SO ₄ and then evaporated. To the solid residue were added 1-decylamine (200 μl, 1 mmol) and N,N-diisopropylethylamine (348 μl, 2 mmol). The reaction mixture was evaporated, the residue was partitioned between chloroform and 0.5 M sodium bicarbonate, the organic layer was washed with water, dried over Na ₂ SO ₄ and evaporated. Compound 7 was purified on a silica gel column (2×15 cm) in ethyl acetate:hexane, 1:1 (v/v). The resulting solution was evaporated, dissolved in dioxane (5 ml), and triphenylphosphine (262 mg, 1 mmol) was added, after which it was kept for 20 h at room temperature, then 1.5 ml of a 25% aqueous solution of ammonia was added and left for 20 h at room temperature. The reaction mixture was evaporated, product 9 was isolated on a silica gel column (2×15 cm) with a solvent mixture of chloroform-ethanol 9:1 (v/v). The resulting solution was evaporated, dissolved in pyridine, acetic anhydride (61 µL, 0.65 mmol) was added, and left for 20 h. room temperature and then evaporated. The solid residue was purified on a column (2×15 cm) with silica gel. Product 1-13 was eluted with the solvent system ethyl acetate:ethanol (9:1). Yield 188 mg (89%) as solid white crystals. UV: λ _max 277 nm. ¹ H NMR (DMSO-d ₆ , 300 MHz) δ 0.86 (3H, t, J=6.7 Hz, -C ₉ H ₁₈ CH ₃ ), 1.22-1.30 (14H, m, -NH-(CH ₂ ) ₂ - C ₇ H ₁₄ -), 1.45-1.58 (2Н, m, -NH-CH ₂ - CH ₂ -), 1.83 (3Н, s, -СОСН ₃ ), 1.85 (3Н, d, J=0.7 Hz, 5- CH ₃ ), 2.07 (2Н, t, J=6.5 Hz, Н-2'), 3.23-3.32 (2Н, m, -NH- CH ₂ -), 3.54 (1H, dt, J=11.9, 4.6 Hz, H-5'b), 3.64 (1H, ddd, J=11.8, 5.2, 3.0 Hz, H-5'a), 3.75 (1H, td, J=4.6, 3.0 Hz, H-4'), 4.27 ( 1H, dtd, J=7.3, 6.5, 4.3 Hz, H-3'), 5.01 (1H, t, J=5.3 Hz, -OH), 6.18 (1H, t, J=6.5 Hz, H-1') , 7.12 (1H, t, J=5.6 Hz, HN ⁴ ), 7.61-7.68 (1H, m, H-6), 8.30 (1H, d, J=7.3 Hz, -NH -COCH ₃ ). ¹³ C NMR (DMSO-d ₆ , 75 MHz) δ 13.09 (5-CH ₃ ), 13.87 (-C ₉ H ₁₈ - C H ₃ ), 22.02, 26.43, 28.64, 28.80, 28.91, 28.96, 31.23 (-NH -(CH ₂ ) ₂ - C ₇ H ₁₄ -), 22.50 (-COCH ₃ ), 28.55 (-NH-CH ₂ -CH ₂ -), 37.75 (-NH-CH ₂ -), 40.17 (C-2' ), 49.02 (C-3'), 61.36 (C-5'), 84.18 (C-1'), 84.85 (C-4'), 101.62 (C-5), 137.03 (C-6), 154.97 ( C-2), 162.63 (C-4), 169.11 (-COCH ₃ ). HRMS (ESI) calculated for C ₂₂ H ₃₈ N ₄ O ₄ , m/z: 445.2790 [M+Na]+, found 445.2796.

Example 14 Synthesis of 3'-acetamido-N ⁴ -dodecyl-5-methyl-2',3'-dideoxycytidine (1-14)

Obtained according to the method described in Example 13, from 5 (134 mg, 0.5 mmol) and 1-dodecylamine (185 mg, 1 mmol) with a yield of 192 mg (85%) in the form of solid white crystals. UV: λ _max 277 nm. ¹ H NMR (DMSO-d ₅ , 300 MHz) δ 0.86 (3H, t, J=6.7 Hz, -C ₁₁ H ₂₂ CH ₃ ), 1.22-1.30 (18H, m, -NH-(CH ₂ ) ₂ - C ₉ H ₁₈ - ), 1.45-1.58 (2Н, m, -NH-CH ₂ - CH ₂ -), 1.83 (3Н, s, -СОСН ₃ ), 1.85 (3Н, d, J=0.7 Hz, 5- CH ₃ ), 2.07 (2Н, t, J=6.5 Hz, Н-2'), 3.23 -3.32 (2Н, m, -NH- CH ₂ -). 3.54 (1H, dt, J=11.9, 4.6 Hz, H-5'b), 3.64 (1H, ddd, J=11.8, 5.2, 3.0 Hz, H-5'a), 3.75 (1H, td, J= 4.6, 3.0 Hz, H-4'), 4.27 (1H, dtd, J=7.3, 6.5, 4.3 Hz, H-3'), 5.01 (1H, t, J=5.3 Hz, -OH), 6.18 (1H , t, J=6.5 Hz, H-1'), 7.12 (1H, t, J=5.6 Hz, HN ⁴ ), .7.61-7.68 (1H, m, H-6), 8.30 (1H, d, J \u003d 7.3 Hz, - NH - COCH ₃ ). ¹³ C NMR (DMSO-d ₆ , 75 MHz) δ 13.09 (5-CH ₃ ), 13.87 (-C ₉ H ₁₈ - C H ₃ ), 22.02, 26.43, 28.64, 28.80, 28.91, 28.96, 31.23 (-NH -(CH ₂ ) ₂ - C ₇ H ₁₄ -), 22.50 (-CO CH ₃ ), 28.55 (-NH-CH ₂ - C H ₂ -), 37.75 (-NH-CH ₂ -), 40.17 ( C -2'), 49.02 (C-3'), 61.36 (C-5'), 84.18 (C-1'), 84.85 (C-4'), 101.62 (C-5), 137.03 (C-6) , 154.97 (C-2), 162.63 (C-4), 169.11 ( -C OCH3). HRMS (ESI) calculated for C ₂₄ H ₄₂ N ₄ O ₄ , m/z: 473.3104 [M+Na]+, found 473.3103.

Example 15 Synthesis of 3'-ethylamino-N ⁴ -decyl-5-metal-2',3'-dideoxycytidine (1-15)

To a solution of azidothymidine 5 (134 mg, 0.5 mmol) in absolute pyridine was added tert-butyldimethylsilyl chloride (98 mg, 0.65 mmol) and left at +37°C for 20 h, after which the resulting solution was evaporated, the residue was partitioned between ethyl acetate and 0.5 M bicarbonate sodium. The organic fraction was collected, dried over Na ₂ SO ₄ and evaporated. 1,2,4-triazole (345 mg, 5 mmol) and 2-chlorophenyl dichlorophosphate (165 μl, 1 mmol) were added to the obtained solid residue and left at room temperature for 20 h. Then the reaction mixture was evaporated, the solid residue was partitioned between ethyl acetate and 0.5 M sodium bicarbonate. The organic phase was dried over Na ₂ SO ₄ and then evaporated. To the solid residue were added 1-decylamine (200 μl, 1 mmol) and N,N-diisopropylethylamine (348 μl, 2 mmol). The reaction mixture was evaporated, the residue was partitioned between chloroform and 0.5 M sodium bicarbonate, the organic layer was washed with water, dried over Na ₂ SO ₄ and evaporated. Compound 7 was purified on a silica gel column (2×15 cm) in ethyl acetate:hexane, 1:1 (v/v). The resulting solution was evaporated, dissolved in dioxane (5 ml), and triphenylphosphine (262 mg, 1 mmol) was added, after which it was kept for 20 h at room temperature, then 1.5 ml of a 25% aqueous solution of ammonia was added and left for 20 h at room temperature. The reaction mixture was evaporated, product 9 was isolated on a silica gel column (2×15 cm) with a mixture of solvents chloroform-ethanol 9:1 (v/v). The resulting solution was evaporated, the solid residue was dissolved in ethanol and cooled to +4°С, acetaldehyde (84 μl, 1.5 mmol) was added, left at +4°С for 2 h, after which sodium borohydride (38 mg, 1 mmol) was added and left at room temperature for 20 h with stirring. The reaction mixture was evaporated, the solid residue was purified on a silica gel column. The product was eluted in the chloroform:ethanol, 9:1 (v/v) system, after which the resulting solution was evaporated, the solid residue was dissolved in dioxane, tetrabutylammonium fluoride trihydrate (205 mg, 0.65 mmol) was added, and left for 20 h at room temperature , after which it was evaporated. The solid residue was purified on a column (2×15 cm) with silica gel. Product 1-15 was eluted with a 3:2 (v/v) solvent system chloroform:methanol. Yield 141 mg (69%) as solid white crystals. UV: λ _max 277 nm. ¹ H NMR (DMSO-d ₆ , 300 MHz) δ 0.86 (3H, t, J=6.5 Hz, -C ₉ H ₁₈ - CH ₃ ), 1.11 (3H, t, J=7.1 Hz, -NH-CH ₂ - CH ₃ ), 1.17-1.38 (14Н, m, -NH-(CH ₂ ) ₂ - C ₇ H ₁₄ -), 1.40-1.61 (4Н, m, -NH-CH ₂ - CH ₂ -), 1.85 ( 3H, d, J=0.7 Hz, 5-CH ₃ ), 2.08 (1H, ddd, J=13.5, 7.4, 6.7 Hz, H-2'b), 2.26 (1H, ddd, J=13.5, 6.1, 4.9 Hz, H-2'a), 2.73 (2H, qd, J=6.9, 2.1 Hz, -NH- CH ₂ -CH ₃ ), 3.29 (2H, dt, J=7.8, 6.4 Hz, -NH- CH ₂ -), 3.48 (1H, ddd, J=7.4, 4.9, 4.1 Hz, H-3'), 3.60 (1H, dd, J=11.9, 3.9 Hz, H-5'b), 3.67 (1H, dd, J=11.8, 3.5 Hz, H-5'a), 3.89 (1H, dt, J=4.1, 3.5 Hz, H-4'), 4.90-5.43 (1H, m, -OH), 6.19 (1H, t , J=6.7, 6.1 Hz, H-1'), 7.14 (1H, t, J=5.6 Hz, HN ⁴ ), 7.56-7.67 (1H, m, H-6). ¹³ C NMR (DMSO-d ₆ , 75 MHz) δ 13.12 (5-CH ₃ ), 13.43 (-NH-CH ₂ - C H ₃ ), 13.89 (-C ₉ H ₁₈ C H ₃ ), 22.04, 26.44, 28.65, 28.82, 28.93, 28.98, 31.25 (-NH-(CH ₂ ) ₂ - C ₇ H ₁₄ -), 28.56 (-NH-CH ₂ - C H ₂ -), 36.68 (-NH- CH ₂ -CH ₃ ), 40.18 (-NH-CH ₂ -), 41.41 (C-2'), 57.27 (C-3'), 61.43 (C-5'), 83.52 (C-4'), 84.45 (C- 1'), 101.66 (C-5), 137.12 (C-6), 155.00 (C-2), 162.66 (C-4). HRMS (ESI) calculated for C ₂₂ H ₄₀ N ₄ O ₃ , m/z: 409.3179 [M+H]+, found 409.3168.

Example 16 Synthesis of 3'-ethylamino-N ⁴ -dodecyl-5-methyl-2',3'-dideoxycytidine (1-16)

Obtained according to the method described in example 15, from 5 (134 mg, 0.5 mmol) and 1-dodecylamine (185 mg, 1 mmol) with a yield of 164 mg (75%) in the form of solid white crystals. UV: λ _max 277 nm. ¹ H NMR (DMSO-d ₆ , 300 MHz) δ 0.86 (3H, t, J=6.9 Hz, -C ₁₁ H ₂₂ - CH ₃ ), 1.12 (3H, t, J=7.1 Hz, -NH-CH ₂ - CH ₃ ), 1.18-1.35 (18Н, m, -NH-(CH ₂ ) ₂ - С ₉ H ₁₈ -), 1.44-1.58 (2Н, m, -NH-CH ₂ - CH ₂ - ), 1.85 ( 3Н, d, J=1.0 Hz, 5-CH ₃ ), 2.08 (1Н, ddd, J=13.9, 7.3, 6.7 Hz, H-2'a), 2.27 (1H, ddd, J=13.8, 6.4, 4.4 Hz, H-2'b), 2.74 (2H, qd, J=7.1, 2.2 Hz, -NH- CH ₂ -CH ₃ ), 3.22-3.35 (2H, m, -NH- CH ₂ -), 3.49 ( 1H, dt, J=7.3, 4.4 Hz, H-3'), 3.60 (1H, dd, J=11.9, 3.9 Hz, H-5'b), 3.67 (1H, dd, J=11.9, 3.5 Hz, H-5'a), 3.90 (1H, dt, J=4.2, 3.5 Hz, H-4'), 4.87-5.33 (1H, m, -OH), 6.19 (1H, t, J=6.5 Hz, H -1'), 7.14 (1H, t, J=5.6 Hz, HN ⁴ ), 7.53-7.66 (1H, m, H-6). ¹³ C NMR (DMSO-d ₆ , 75 MHz) δ 13.12 (5-CH ₃ ), 13.34 (-NH-CH ₂ - C H ₃ ), 13.90 (-C ₁₁ H ₂₂ - C H ₃ ), 22.04, 26.45 , 28.66, 28.83, 28.97, 31.25 (NH-(CH ₂ ) ₂ - C ₉ H ₁₈ -), 28.56 (-NH-CH ₂ - C H ₂ -), 36.59 (-NH-CH ₂ -CH ₃ ), 40.18 (-NH-CH ₂ -), 41.39 (C-2'), 57.25 (C-3'), 61.42 (C-5'), 83.43 (C-4'), 84.44 (C-1' ), 101.67 (C-5), 137.12 (C-6), 154.99 (C-2), 162.66 (C-4). HRMS (ESI) calculated for C ₂₄ H ₄₄ N ₄ O ₃ , m/z: 437.3492 [M+H]+, found 437.3495.

Example 17 Synthesis of 3'-diethylamino-N ⁴ -decyl-5-methyl-2',3'-dideoxycytidine (1-17)

To a solution of azidothymidine 5 (134 mg, 0.5 mmol) in absolute pyridine was added tert-butyldimethylsilyl chloride (98 mg, 0.65 mmol) and left at +37°C for 20 h, after which the resulting solution was evaporated, the residue was partitioned between ethyl acetate and 0.5 M bicarbonate sodium. The organic fraction was collected, dried over Na ₂ SO ₄ and evaporated. 1,2,4-triazole (345 mg, 5 mmol) and 2-chlorophenyl dichlorophosphate (165 μl, 1 mmol) were added to the obtained solid residue and left at room temperature for 20 h. Then the reaction mixture was evaporated, the solid residue was partitioned between ethyl acetate and 0.5 M sodium bicarbonate. The organic phase was dried over Na ₂ SO ₄ and then evaporated. To the solid residue were added 1-decylamine (200 μl, 1 mmol) and N,N-diisopropylethylamine (348 μl, 2 mmol). The reaction mixture was evaporated, the residue was partitioned between chloroform and 0.5 M sodium bicarbonate, the organic layer was washed with water, dried over Na ₂ SO ₄ and evaporated. Compound 7 was purified on a column (2×15 cm) with silica gel in the system ethyl acetate:hexane in a ratio of 1:1 (v/v). The resulting solution was evaporated, dissolved in dioxane (5 ml), and triphenylphosphine (262 mg, 1 mmol) was added, after which it was kept for 20 h at room temperature, then 1.5 ml of a 25% aqueous solution of ammonia was added and left for 20 h at room temperature. The reaction mixture was evaporated, product 9 was isolated on a silica gel column (2×15 cm) with a mixture of solvents chloroform-ethanol 9:1 (v/v). The resulting solution was evaporated, the solid residue was dissolved in ethanol and cooled to +4°С, acetaldehyde (560 μl, 10 mmol) was added, left at +4°С for 2 h, after which sodium cyanoborohydride (94 mg, 1.5 mmol) was added and kept at room temperature for 20 h with stirring. The reaction mixture was evaporated, the solid residue was purified on a silica gel column. The product was eluted in a chloroform:ethanol system in a ratio of 9:1 (v/v), after which the resulting solution was evaporated, the solid precipitate was dissolved in dioxane, tetrabutylammonium fluoride trihydrate (205 mg, 0.65 mmol) was added, and left for 20 h at room temperature. temperature and then evaporated. The solid residue was purified on a column (2×15 cm) with silica gel. Product 1-17 was eluted with a 4:1 (v/v) solvent system chloroform:ethanol. Yield 170 mg (78%) as solid white crystals. UV: λ _max 277 nm. ¹ H NMR (DMSO-d ₆ , 300 MHz) δ 0.86 (3H, t, J=6.6 Hz, -C ₉ H ₁₈ - CH ₃ ), 1.09 (6H, t, J=7.1 Hz, -N-(CH ₂ - CH ₃ ) ₂ ), 1.17-1.38 (14Н, m, -NH-(CH ₂ ) ₂ - C ₇ H ₁₄ -), 1.40-1.61 (4H, m, -NH-CH ₂ -CH ₂ -) , 1.85 (3Н, d,J=0.7 Hz, 5-CH ₃ ), 2.08 (1H, ddd, J=13.5, 7.7, 6.7 Hz, H-2'b), 2.26 (1Н, ddd, J=13.5, 6.1, 4.7 Hz, H-2'a), 2.65 (4H, qd, J=6.9, 2.1 Hz, -N-(CH ₂ -CH ₃ ) ₂ ), 3.29 (2H, dt, J=7.8, 6.4 Hz , -NH-CH ₂ -). 3.45 (1H, ddd, J=1.1, 4.7, 4.5 Hz, H-3'), 3.60 (1H, dd, J=11.9, 3.9 Hz, H-5'b), 3.67 (1H, dd, J=11.8 , 3.5 Hz, H-5'a), 3.89 (1H, dt, J=4.5, 3.5 Hz, H-4'), 4.90-5.43 (1H, m, -OH), 6.19 (1H, t, J= 6.7, 6.1 Hz, H-1'), 7.14 (1H, t, J=5.6 Hz, HN ⁴ ), 7.56-7.67 (1H, m, H-6). ¹³ C NMR (DMSO-d ₆ , 75 MHz) δ 13.12 (5-CH ₃ ), 13.43 (-NH-CH ₂ -CH ₃ ), 13.89 (-C ₉ H ₁₈ CH ₃ ), 22.04, 26.44, 28.65, 28.82, 28.93, 28.98, 31.25 (-NH-(CH ₂ ) ₂ -C ₇ H ₁₄ -), 28.56 (-NH-CH ₂ -CH ₂ -), 36.68 (-NH-CH ₂ -CH ₃ ), 40.18 (-NH-CH ₂ -), 41.41 (C-2'), 57.27, (C-3'), 61.43 (C-5'), 83.52 (C-4'), 84.45 (C-1'), 101.66 (C-5), 137.12 (C-6), 155.00 (C-2), 162.66 (C-4). HRMS (ESI) calculated for C ₂₄ H ₄₄ N ₄ O ₃ , m/z: 437.3492 [M+H]+, found 437.3494.

Example 18 Synthesis of 3'-diethylamino-N ⁴ -dodecyl-5-methyl-2',3'-dideoxycytidine (1-18)

Obtained according to the method described in Example 17, from 5 (134 mg, 0.5 mmol) and 1-dodecylamine (185 mg, 1 mmol) with a yield of 153 mg (66%) in the form of solid white crystals. UV: λ _max 211 nm. ¹ H NMR (DMSO-d ₆ , 300 MHz) δ 0.86 (3H, t, J=6.6 Hz, -C ₁₁ H ₂₂ -CH ₃ ), 1.09 (6H, t, J=7.1 Hz, -N-(CH ₂ - CH ₃ ) ₂ ), 1.17-1.38 (18Н, m, -NH-(CH ₂ ) ₂ - C ₉ H ₁₈ -), 1.40-1.61 (4H, m, -NH-CH ₂ -CH ₂ -) , 1.85 (3H, d, J=0.7 Hz, 5-CH ₃ ), 2.08 (1H, ddd, J=13.5, 7.7, 6.7 Hz, H-2'b), 2.26 (1H, ddd, J=13.5, 6.1, 4.7 Hz, H-2'a), 2.65 (4H, qd, J=6.9, 2.1 Hz, -N-( CH ₂ -CH ₃ ) ₂ ), 3.29 (2H, dt, J=7.8, 6.4 Hz , -NH-CH ₂ -), 3.45 (1H, ddd, J=7.7, 4.7, 4.5 Hz, H-3'), 3.60 (1H, dd, J=11.9, 3.9 Hz, H-5'b), 3.67 (1H, dd, J=11.8, 3.5 Hz, H-5'a), 3.89 (1H, dt, J=4.5, 3.5 Hz, H-4'), 4.90-5.43 (1H, m, -OH) , 6.19 (1H, t, J=6.7, 6.1 Hz, H-l'), 7.14 (1H, t, J=5.6 Hz, HN ⁴ ), 7.56-7.67 (1H, m, H-6). ¹³ C NMR (DMSO-d ₆ , 75 MHz) δ 13.12 (5-CH ₃ ), 13.43 (-NH-CH ₂ - C H ₃ ), 13.89 (-C ₉ H ₁₈ C H ₃ ), 22.04, 26.44, 28.65, 28.82, 28.93, 28.98, 31.25 (-NH-(CH ₂ ) ₂ - C ₇ H ₁₄ -), 28.56 (-NH-CH ₂ - C H ₂ -), 36.68 (-NH- CH ₂ -CH ₃ ), 40.18 (-NH-CH ₂ -), 41.41 (C-2'), 57.27 (C-3'), 61.43 (C-5'), 83.52 (C-4'), 84.45 (C- 1'), 101.66 (C-5), 137.12 (C-6), 155.00 (C-2), 162.66 (C-4). HRMS (ESI) calculated for C ₂₆ H ₄₈ N ₄ O ₃ , m/z: 465.3805 [M+H]+, found 465.3806.

Example 19 Synthesis of 3'-dimethylamino-N ⁴ -decyl-5-methyl-2',3'-dideoxycytidine (1-19)

To a solution of azidothymidine 5 (134 mg, 0.5 mmol) in absolute pyridine was added tert-butyldimethylsilyl chloride (98 mg, 0.65 mmol) and left at +37°C for 20 h, after which the resulting solution was evaporated, the residue was partitioned between ethyl acetate and 0.5 M bicarbonate sodium. The organic fraction was collected, dried over Na ₂ SO ₄ and evaporated. 1,2,4-triazole (345 mg, 5 mmol) and 2-chlorophenyl dichlorophosphate (165 μl, 1 mmol) were added to the obtained solid residue and left at room temperature for 20 h. Then the reaction mixture was evaporated, the solid residue was partitioned between ethyl acetate and 0.5 M sodium bicarbonate. The organic phase was dried over Na ₂ SO ₄ and then evaporated. To the solid residue were added 1-decylamine (200 μl, 1 mmol) and N,N-diisopropylethylamine (348 μl, 2 mmol). The reaction mixture was evaporated, the residue was partitioned between chloroform and 0.5 M sodium bicarbonate, the organic layer was washed with water, dried over Na ₂ SO ₄ and evaporated. Compound 7 was purified on a column (2×15 cm) with silica gel in the system ethyl acetate:hexane in a ratio of 1:1 (v/v). The resulting solution was evaporated, dissolved in dioxane (5 ml), and triphenylphosphine (262 mg, 1 mmol) was added, after which it was kept for 20 h at room temperature, then 1.5 ml of a 25% aqueous solution of ammonia was added and left for 20 h at room temperature. The reaction mixture was evaporated, product 9 was isolated on a silica gel column (2×15 cm) with a solvent mixture of chloroform-ethanol 9:1 (v/v). The resulting solution was evaporated, the solid residue was dissolved in methanol, 37% formalin (370 μl, 5 mmol) was added, waited for 2 h, after which sodium cyanoborohydride (94 mg, 1.5 mmol) was added and left at room temperature for 20 h with stirring . The reaction mixture was evaporated, the solid residue was purified on a silica gel column. The product was eluted in a 9:1 (v/v) chloroform:ethanol system, after which the resulting solution was evaporated, the solid residue was dissolved in dioxane, tetrabutylammonium fluoride trihydrate (205 mg, 0.65 mmol) was added, and left for 20 h at room temperature. temperature and then evaporated. The solid residue was purified on a column (2×15 cm) with silica gel. Product 1-17 was eluted with a solvent system of chloroform:ethanol in a ratio of 3:2 (v/v). Yield 125 mg (61%) as solid white crystals. UV: λ _max 277 nm. ¹ H NMR (DMSO-d ₆ , 300 MHz) δ 0.86 (3H, t, J=6.6 Hz, -C ₉ H ₁₈ - CH ₃ ), 1.17-1.38 (14H, m, -NH-(CH ₂ ) ₂ - C ₇ H ₁₄ -), 1.40-1.61 (4Н, m, -NH-CH ₂ - CH ₂ -), 1.85 (3Н, d, J=0.7 Hz, 5-CH ₃ ), 2.08 (1H, ddd, J=13.5, 7.7, 6.7 Hz, H-2'b), 2.26 (1H, ddd, J=13.5, 6.1, 4.8 Hz, H-2'a), 2.46 (6H, s, -N-( CH ₃ ) ₂ ), 3.29 (2Н, dt, J=7.8, 6.4 Hz, -NH- CH ₂ -), 3.45 (1H, ddd, J=7.7, 4.8, 4.3 Hz, H-3'), 3.60 (1H, dd, J=11.9, 3.9 Hz, H-5'b), 3.67 (1H, dd, J=11.8, 3.5 Hz, H-5'a), 3.89 (1H, dt, J=4.3, 3.5 Hz, H -4'), 4.90-5.43 (1H, m, -OH), 6.19 (1H, t, J=6.7, 6.1 Hz, H-1'), 7.14 (1H, t, J=5.6 Hz, HN ⁴ ) , 7.56-7.67 (1H, m, H-6). ¹³ C NMR (DMSO-d ₆ , 75 MHz) δ 13.12 (5-CH ₃ ), 13.43 (-NH-CH ₂ -CH ₃ ), 13.89 (-C ₉ H ₁₈ CH ₃ ), 22.04, 26.44, 28.65, 28.82, 28.93, 28.98, 31.25 (-NH-(CH ₂ ) ₂ - C ₇ H ₁₄ -), 28.56 (-NH-CH ₂ - C H ₂ -), 36.68 (-NH- C H ₂ -CH ₃ ) , 40.18 (-NH-CH ₂ -), 41.41 (C-2'), 57.27, (C-3'), 61.43 (C-5'), 83.52 (C-4'), 84.45 (C-1' ), 101.66 (C-5), 137.12 (C-6), 155.00 (C-2), 162.66 (C-4). HRMS (ESI) calculated for C ₂₂ H ₄₀ N ₄ O ₃ , m/z: 409.3179 [M+H]+, found 409.3175.

Example 20 Synthesis of 3'-dimethylamino-N ⁴ -dodecyl-5-methyl-2',3'-dideoxycytidine (1-20)

Obtained according to the method described in example 19, from 5 (134 mg, 0.5 mmol) and 1-dodecylamine (185 mg, 1 mmol) with a yield of 162 mg (74%) in the form of solid white crystals. UV: λ _max 277 nm. ¹ H NMR (DMSO-d ₆ , 300 MHz) δ 0.86 (3H, t, J=6.6 Hz, -C ₁₁ H ₂₂ - CH ₃ ), 1.17-1.38 (18H, m, -NH-(CH ₂ ) ₂ - C ₉ H ₁₈ -), 1.40-1.61 (4Н, m, -NH-CH ₂ - CH ₂ -), 1.85 (3Н, d, J=0.7 Hz, 5-CH ₃ ), 2.08 (1Н, ddd, J=13.5, 7.7, 6.7 Hz, H-2'b), 2.26 (1H, ddd, J=13.5, 6.1, 4.8 Hz, H-2'a), 2.46 (6H, s, -N-( CH ₃ ) ₂ ), 3.29 (2H, dt, J=7.8, 6.4 Hz, -NH- CH ₂ -), 3.45 (1H, ddd, J=7.7, 4.8, 4.3 Hz, H-3'), 3.60 (1H, dd, J=11.9, 3.9 Hz, H-5'b), 3.67 (1H, dd, J=11.8, 3.5 Hz, H-5'a), 3.89 (1H, dt, J=4.3, 3.5 Hz, H -4'), 4.90-5.43 (1H, m, -OH), 6.19 (1H, t, J=6.7, 6.1 Hz, H-1'), 7.14 (1H, t, J=5.6 Hz, HN ⁴ ) , 7.56-7.67 (1H, m, H-6), ¹³ C NMR (DMSO-d ₆ , 75 MHz) δ 13.12 (5-CH3), 13.43 (-NH-CH ₂ - C H ₃ ), 13.89 (- C ₉ H ₁₈ C H ₃ ), 22.04, 26.44, 28.65, 28.82, 28.93, 28.98, 31.25 (-NH-(CH ₂ ) ₂ - C ₇ H ₁₄ -), 28.56 (-NH-CH ₂ - C H ₂ -), 36.68 (-NH-CH ₂ -CH ₃ ), 40.18 (-NH-CH ₂ -), 41.41 (C-2'), 57.27, (C-3'), 61.43.(C-5' ), 83.52 (C-4'), 84.45 (C-1'), 101.66 (C-5), 137.12 (C-6), 155.00 (C-2), 162.66 (C-4). HRMS (ESI) calculated for C ₂₄ H ₄₄ N ₄ O ₃ , m/z: 437.3492 [M+H]+, found 437.3486.

Example 21 Synthesis of 3'-O-(8-hydroxy-3,6-dioxaoctyloxycarbonyl)-N ⁴ -decyl-2'-deoxycytidine (1-21)

To a solution of thymidine (2) (121 mg, 0.5 mmol) in absolute pyridine, cooled to +4°С, was added tert-butyldimethylsilyl chloride (90 mg, 0.6 mmol) and left at +4°С for 20 h. The resulting solution was evaporated, the solid residue was partitioned between ethyl acetate and 0.5 M sodium bicarbonate. The organic phase was dried over Na₂SO₄, after which it was evaporated. The solid residue was dissolved in DMF (3 ml) and CDI (297 mg, 1.83 mmol) was added, after which it was left at +37°C for 48 h. Then triethylene glycol (273 μl, 2 mmol) in dioxane was added and kept for 48 h at + 37°C. The reaction mixture was evaporated, the residue was partitioned between 40% hexane in chloroform (10 ml) and 0.5 M sodium bicarbonate solution (10 ml), the organic layer was washed with water (5×5 ml), dried over Na₂SO₄, evaporated, reevaporated with pyridine and dissolved in pyridine. TBDMSCl (98 mg, 0.65 mmol) was added to the solution and left at +20°C for 20 h, then partitioned between chloroform (10 ml) and 0.5 M sodium bicarbonate solution (10 ml), the organic layer was washed with water (5× 5 ml), dried over Na₂SO₄. Product 12 was purified on a silica gel column (2×15 cm) in chloroform: ethyl acetate: ethanol, 5:5:0.1 (v/v/v). The target fraction was evaporated, reevaporated with pyridine and dissolved in pyridine (5 ml). 1,2,4-triazole (345 mg, 5 mmol) and 2-chlorophenyl dichlorophosphate (165 μl, 1 mmol) were added to the solution cooled to 0°C. The mixture was left for 20 h at room temperature, then evaporated, the residue was partitioned between chloroform and 0.5 M sodium bicarbonate, the organic layer was washed with water, dried over Na₂SO₄, evaporated, dissolved in anhydrous dioxane (3 ml), cooled to 0°C and added 1-decylamine (200 μl, 1 mmol). After 20 h at room temperature, the mixture was evaporated, the residue was partitioned between chloroform and water, the organic layer was washed with water, dried over Na₂SO₄, evaporated. The residue was dissolved in dioxane (3 ml) and Bu₄NF⋅3H₂O (380 mg, 1.2 mmol). The reaction mixture was evaporated, the residue was partitioned between 40% hexane in chloroform (10 ml) and 0.5 M sodium bicarbonate solution (10 ml), the organic layer was washed with water (5×5 ml), dried over Na₂SO₄, evaporated. Compound 1-21 was purified on a silica gel column (2×15 cm) and eluted with a solvent system of ethyl acetate:ethanol, 20:1 (v/v). Yield 175 mg (63%) as solid white crystals. UV: λ_max 273 nm.^oneH NMR (400 MHz, DMSO-d₆) δ 0.85 (3Н, t, J=6.8 Hz, -CH₂-CH ₃ ), 1.23-1.29 (14Н, m, -NH-(CH₂)₂-(CH ₂ ) ₇ -), 1.46-1.56 (2Н, m, -NH-CH₂-CH ₂ -), 1.84 (3H, d, J=1.1 Hz, 5-CH₃), 2.19 (1H, ddd, J=14.2, 8.8, 5.9 Hz, 2'-Ha), 2.28 (1Н, ddd, J=14.0, 5.7, 1.8 Hz, 2'-Hb), 3.25-3.29 (2Н, m, -NH-CH₂-), 3.40-3.65 (12H, m, 5'-CH₂+-CH ₂ OC₂ H ₄ OC ₂ H ₄OH, 4.02 (1Н, td, J=3.6, 1.8 Hz, 4'-Н), 4.20-4.25 (2Н, m, -СО₃-CH₂-), 4.54 (1Н, t, J=5.5 Hz, -CH₂-CH₂-OH), 5.13 (1H, dt, J=5.9, 1.8 Hz, 3'-H), 5.15 (1H, t, J=5.3 Hz, 5'-OH), 6.17 (1H, dd, J=8.8, 5.6 Hz, 1'-H), 7.14 (1H, t, J=5.7 Hz, N⁴-H), 7.54-7.58 (1H, m, 6-H).¹³C NMR (101 MHz, DMSO-d₆) δ 13.09 (5-CH₃), 13.88(-CH₂-CH₃), 22.02, 26.41, 28.51, 28.63, 28.78, 28.90, 28.95, 31.23 (-NH-CH₂-(CH₂ ) ₈ -), 36.96 (2'-C), 40.18 (-NH-CH₂-), 60.18(-CH₂-CH₂-OH), 61.37 (5'-C), 67.01, 68.06, 69.72, 72.31 (-CO₃-CH ₂ABOUTFROM ₂ H ₄ ABOUTCH ₂ -CH ₂ -OH), 78.62 (3'-C), 84.04 (1'-C), 84.60 (4'-C), 102.02 (5-C), 136.91 (6-C), 153.84 (-CO₃-), 154.90 (2-C), 162.65 (4-C). HRMS (ESI) calculated for C₂₇H₄₇N₃O_nine, m/z: 558.3391 [M+H]⁺, found 558.3400.

Example 22 Synthesis of 3'-O-(8-hydrooxy-3,6-dioxaoctyloxycarbonyl)-N ⁴ -dodecyl-2'-deoxycytidine (1-22)

Obtained according to the method described in example 21, from 2 (121 mg, 0.5 mmol) and 1-dodecylamine (185 mg, 1 mmol). Yield 191 mg (65%) as solid white crystals. UV: λ _max 273 nm. ¹ H NMR (300 MHz, DMSO-d ₆ ) δ 0.85 (3H, t, J=6.6 Hz, -CH ₂ -CH ₃ ), 1.21-1.30 (18H, m, -NH-(CH ₂ ) ₂ - ( CH ₂ ) ₉ - ). 1.46-1.57 (2H, m, -NH-CH ₂ - CH ₂ -), 1.86 (3H, s, 5-CH ₃ ), 2.20 (1H, ddd, J=14.1, 8.8, 5.8 Hz, 2'-Na ), 2.30 (1H, ddd, J=14.1, 5.8, 1.8 Hz, 2'-Hb), 3.26-3.33 (2Н, m, -NH-CH ₂ -), 3.40-3.66 (12Н, m, 5'- CH ₂ + - CH ₂ O C ₂ H ₄ O C ₂ H ₄ OH), 4.04 (1H, td, J \u003d 3.6, 1.8 Hz, 4'-H), 4.18-4.27 (2H, m, -CO ₃ - CH ₂ -), 4.55 (1H, t, J=5.4 Hz, -CH ₂ -CH ₂ -OH), 5.15 (1H, dt, J=5.8, 1.8 Hz, 3'-H), 5.19 (1H, t , J=5.4 Hz, 5'-OH), 6.19 (1Н, dd, J=8.8, 5.6 Hz, 1'-Н), 7.19 (1H, t, J=5.6 Hz, N ⁴ -H), 7.59 ( 1H, s, 6-H). ¹³ C NMR (75 MHz, DMSO-d ₆ ) δ 13.10 (5-CH ₃ ), 13.86 (-CH ₂ -CH ₃ ), 22.09, 26.51, 28.59, 28.73, 28.90, 29.05, 29.08, 31.31 (-NH- CH ₂ - (CH ₂ ) ₁₀ -). 37.12 (2'-C), 40.27 (-NH-CH ₂ -), 60.25 (-CH ₂ -CH ₂ -OH), 61.43 (5'-C), 67.02, 68.13, 69.76, 69.81, 72.38 (-CO ₃ - CH ₂ O C ₂ H ₄ O CH ₂ -CH ₂ -OH), 78.72 (3'-C), 84.18 (l'-C), 84.74 (4'-C), 102.15 (5-C), 136.90 (6-C), 153.90 (-CO ₃ -), 155.08 (2-C), 162.72 (4-C). HRMS (ESI) C ₂₉ H ₅₁ N ₃ O ₉ , m/z: 586.3698 [M+H] ⁺ , found 586.3717.

Example 23 Inhibition of Fungal Growth

Т.А.

G.K. Nuraeva, D.V. Yanvarev, М. Khomutov, E.N. Khurs, S.N. Kochetkov, J.

A.A. Zhgun, A.R. Khomutov, Hydroxylamine analogue of agmatine: Magic bullet for arginine decarboxylase, Biomolecules. 10 (2020) 1-16. https://doi.org/10.3390/biom10030406] с некоторыми модификациями. Клетки собирали из скошенных агаров и разбавляли 0,9% раствором NaCl до OD₆₀₀=0,5 (основная концентрация) с последующим серийным десятикратным разбавлением тем же растворителем. Затем 2 мкл клеточной суспензии инокулировали на чашки Петри со средой ЧДА, приготовленной с добавлением или без добавления тестируемых соединений (N⁴-модифицированных 5-метил-2'-дезоксицитидинов (1-1 - 1-22) или 5-фторцитозина (5FC) в качестве положительного контроля) в концентрациях 0,5 мМ, 0.7 мМ или 3 мМ. Инокулированные чашки инкубировали в течение 60 суток при 26°С. Ингибирующее действие соединений измеряли каждые три дня после инокуляции и оценивали по соотношению роста колоний на ЧДА к контрольному росту колоний на агаризованной среде ЧДА без каких-либо добавок. Процент ингибирования роста грибков (FGI) рассчитывали по формуле:Strains of filamentous fungi were cultivated on Czapek-Dox agar medium (ChDA) (30 g/l sucrose, 2 g/l NaNO ₃ , 1 g/l K ₂ HPO ₄ , 0.5 g/l MgSO ₄ × 7 H ₂ O , 0.5 g/l KCl, 0.01 g/l FeSO ₄ × 7 H ₂ O, 20 g/l agar, pH 7.0-7.4). To determine the toxic effect of N ⁴ -modified 5-methyl-2'-deoxycytidines on the growth of fungal cells, the drop dilution method was used [M.T.

T.A.

GK Nuraeva, DV Yanvarev, M. Khomutov, EN Khurs, SN Kochetkov, J.

AA Zhgun, AR Khomutov, Hydroxylamine analogue of agmatine: Magic bullet for arginine decarboxylase, Biomolecules. 10(2020) 1-16. https://doi.org/10.3390/biom10030406] with some modifications. Cells were collected from agar slants and diluted with 0.9% NaCl solution to OD ₆₀₀ =0.5 (basic concentration) followed by serial tenfold dilution with the same solvent. Then 2 µl of the cell suspension was inoculated onto Petri dishes with analytical medium prepared with or without the addition of test compounds (N ⁴ -modified 5-methyl-2'-deoxycytidines (1-1 - 1-22) or 5-fluorocytosine (5FC) as a positive control) at concentrations of 0.5 mM, 0.7 mM or 3 mM. Inoculated cups were incubated for 60 days at 26°C. The inhibitory effect of the compounds was measured every three days after inoculation and was assessed by the ratio of colony growth on NDA to control colony growth on agar medium of NDA without any additives. The percentage of fungal growth inhibition (FGI) was calculated using the formula:

FGI%=[(D _c -D _t ) / D _c ] × 100,

where D _c is the diameter of the colony in the control set,

D _t is the diameter of the colony in the treatment set.

The inhibitory effect was evaluated for each concentration of the test compound in duplicate and in triplicate.

Table 1. Synthesized N ⁴ -modified 5-methyl-2'-deoxyribocytidine.

Claims (28)

1. N ⁴ -modified 5-methyl-2'-deoxycytidines containing an extended alkyl substituent in their composition, inhibiting the growth of filamentous fungi, represented by the general formula:

where R ₁ and R ₂ independently of each other mean: R ₁ =-C _n H _2n+1 , -OC _n H _2n+1 (n=8-12); R ₂ \u003d -OH, -N ₃ , -NH ₂ , -NHC (O) CH ₃ , -N (CH ₃ ) ₂ , -NHC ₂ H ₅ , -N (C ₂ H ₅ ) ₂ , -O (CH ₂ CH ₂ O) ₃ H. 2. Compounds according to claim 1, which are: N ⁴ -octyl-5-methyl-2'-deoxycytidine; N ⁴ -decyl-5-methyl-2'-deoxycytidine; N ⁴ -dodecyl-5-methyl-2'-deoxycytidine; N ⁴ -octyloxy-5-methyl-2'-deoxycytidine; N ⁴ -decyloxy-5-methyl-2'-deoxycytidine; N ⁴ -undecyloxy-5-methyl-2'-deoxycytidine; N ⁴ -dodecyloxy-5-methyl-2'-deoxycytidine; 3'-azido-N ⁴ -octyl-5-methyl-2',3'-dideoxycytidine; 3'-azido-N ⁴ -decyl-5-methyl-2',3'-dideoxycytidine; 3'-azido-N ⁴ -dodecyl-5-methyl-2',3'-dideoxycytidine; 3'-amino-N ⁴ -decyl-5-methyl-2',3'-dideoxycytidine; 3'-amino-N ⁴ -dodecyl-5-methyl-2',3'-dideoxycytidine; 3'-acetamido-N ⁴ -decyl-5-methyl-2',3'-dideoxycytidine; 3'-acetamido-N ⁴ -dodecyl-5-methyl-2',3'-dideoxycytidine; 3'-ethylamino-N ⁴ -decyl-5-methyl-2',3'-dideoxycytidine; 3'-ethylamino-N ⁴ -dodecyl-5-methyl-2',3'-dideoxycytidine; 3'-diethylamino-N ⁴ -decyl-5-methyl-2',3'-dideoxycytidine; 3'-diethylamino-N ⁴ -dodecyl-5-methyl-2',3'-dideoxycytidine; 3'-dimethylamino-N ⁴ -decyl-5-methyl-2',3'-dideoxycytidine; 3'-dimethylamino-N ⁴ -dodecyl-5-methyl-2',3'-dideoxycytidine; 3'-O-(8-hydroxy-3,6-dioxaoctyloxycarbonyl)-N ⁴ -decyl-2'-deoxycytidine; 3'-O-(8-hydroxy-3,6-dioxaoctyloxycarbonyl)-N ⁴ -dodecyl-2'-deoxycytidine.

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