Preparation method of vatacostat and intermediate thereof
Technical Field
The invention relates to the field of medicinal chemistry, and in particular relates to a preparation method of valdoxetamol and an intermediate thereof.
Background
Varkovista (Vadadustat), CAS: 1000025-07-9, having the chemical name N- (5- (3-chlorophenyl) -3-hydroxypyridine-2-carbonyl) glycine, is an oral Hypoxia Inducible Factor (HIF) stabilizer and is currently used in phase 3 clinical trials to treat anemia associated with chronic kidney disease; the chemical structural formula is as follows:
synthetic route of Vadadustat disclosed in US patent 20070299086: 3, 5-dichloro-2-cyanopyridine is used as a starting material, and Vadadustat is obtained through benzyl substitution reaction, hydrolysis, coupling, hydrogenation, substitution, coupling and hydrolysis reaction in 7 steps, wherein the total yield is 9%. The route is long and the yield is low. Wherein, the benzyl substitution reaction in the first step has harsh conditions and cannot be amplified (microwave reaction, 190 ℃), and in addition, the hydrogenation reaction and the coupling reaction are also carried out, 5 times of column chromatography purification are needed totally, the operation is inconvenient, the cost is high, and the route is not suitable for industrial amplification.
A synthetic route for the preparation of Vadadustat is disclosed in US patent US 20120309977: 3-chlorobenzoic acid and 3, 5-dichloro-2-cyanopyridine are used as initial raw materials, and Vadadustat is obtained through catalytic coupling, methoxy substitution, cyano hydrolysis, condensation and ester hydrolysis reaction, and the reaction is carried out for 5 steps.
Therefore, research on a preparation method of Vadadustat and an intermediate thereof is still needed to obtain a preparation method which is simple and convenient to operate, easy to implement, high in yield, high in purity, low in cost, environment-friendly and suitable for industrial scale-up production.
Disclosure of Invention
The invention provides a preparation method of valdoxetamol and an intermediate thereof, wherein the structure of an intermediate compound (6) is as follows:
according to the preparation method, the compound (3) is used as a starting material, a hydrolysis reaction is carried out to obtain the compound (4), the compound (4) and the compound (5) are subjected to a condensation reaction to obtain the compound (6), and the compound (6) can be further subjected to a hydrolysis reaction to obtain vadadustat.
The specific reaction route is as follows:
in one aspect, the invention provides a preparation method of a vatacostat intermediate compound (6),
which comprises reacting a compound (4) with a glycine methyl ester represented by a compound (5) or a salt thereof in a reaction solvent in the presence of a condensing agent, followed by post-treatment to obtain a compound (6). The method for preparing the intermediate compound (6) has the advantages of mild reaction conditions, high yield, simple post-treatment and suitability for industrial amplification.
In some embodiments, the condensing agent is selected from at least one of CDI, EDCI, DCC, or PyBOP. In some embodiments, the condensing agent is CDI, facilitating the production and availability of the target product.
In some embodiments, the reaction solvent is an organic solvent, and may be selected from at least one of DCM, DMSO, DMF, DMAC, or THF. In some embodiments, the reaction solvent is DCM, which facilitates the reaction and work-up.
In some embodiments, the compound (4) to condensing agent molar ratio is 1:1.0 to 1: 3.0; or the molar ratio is 1:1.2-1: 2.0.
In some embodiments, the molar ratio of compound (4) to glycine methyl ester represented by compound (5) or a salt thereof is 1:1.0 to 1: 3.0; or the molar ratio is 1:1.2-1: 2.5; or the molar ratio is 1:1.5-1: 2.0.
In some embodiments, the reaction temperature of the reaction is from 0 ℃ to 100 ℃; or the reaction temperature is 10-80 ℃; or the reaction temperature is 15-70 ℃; or the reaction temperature is 20-60 ℃.
In some embodiments, the reaction time of the reaction is from 10min to 10 h; or the reaction time is 20min-8 h; or the reaction time is 30min-5 h; or the reaction time is 1h-3 h.
In some embodiments, the post-processing comprises: stopping reaction, removing solvent, adding water for crystallization, filtering, washing filter cake with water, and vacuum drying.
In some embodiments, the post-processing comprises: washing the filter cake with water, and vacuum drying; or adding 50mL-200mL of water into the filter cake, washing, and then drying in vacuum at 60-100 ℃ for 12-24 h.
In some embodiments, a method of preparing the intermediate compound (6) of valdoxat comprises: in a reaction solvent, in the presence of a condensing agent, reacting a compound (4) with glycine methyl ester or a salt thereof shown as a compound (5) at 0-100 ℃, removing the solvent after the reaction is finished, adding water for crystallization, performing suction filtration, washing a filter cake with water, and performing vacuum drying to obtain a compound (6).
In some embodiments, a method of preparing the intermediate compound (6) of valdoxat comprises: in a reaction solvent, reacting a compound (4) with glycine methyl ester or a salt thereof represented by a compound (5) at 0 ℃ to 100 ℃ in the presence of a condensing agent; after the reaction is finished, removing the solvent, adding water to separate out crystals, performing suction filtration, washing a filter cake with water, and performing vacuum drying to obtain the compound (6).
In some embodiments, a method of preparing the intermediate compound (6) of valdoxat comprises: in DCM, in the presence of CDI, glycine or a salt thereof shown as a compound (4) and a compound (5) reacts at 0-60 ℃, after the reaction is finished, a solvent is removed, water is added for crystallization, the crystal is filtered, a filter cake is washed by water, and then the filter cake is dried in vacuum to obtain a compound (6).
In some embodiments, a method of preparing the intermediate compound (6) of valdoxat comprises: in DCM, compound (4) is first reacted with CDI at 0 deg.C-60 deg.C; then reacting with glycine methyl ester or salt thereof shown in a compound (5) at 0-60 ℃; after the reaction is finished, removing the solvent, adding water to separate out crystals, performing suction filtration, washing a filter cake with water, and performing vacuum drying to obtain the compound (6).
In some embodiments, a method of preparing the intermediate compound (6) of valdoxat comprises: in DCM, in the presence of CDI, glycine methyl ester or a salt thereof shown as a compound (4) and a compound (5) reacts at 0-60 ℃, after the reaction is finished, a solvent is removed, water is added for crystallization, the filtration is carried out, a filter cake is washed by water, and the vacuum drying is carried out to obtain a compound (6); wherein the molar ratio of the compound (4) to the CDI is 1:1.0-1:3.0, and the molar ratio of glycine or a salt thereof represented by the compound (4) and the compound (5) is 1:1.0-1: 3.0.
In some embodiments, the preparation method of the compound (6) can further comprise reacting the compound (3) in the presence of a base, and performing post-treatment to obtain the compound (4),
the alkali is at least one of sodium methoxide, sodium ethoxide, sodium hydroxide or potassium hydroxide.
In some embodiments, the base is sodium methoxide, sodium hydroxide, potassium hydroxide, or sodium ethoxide, or a combination thereof. The feeding molar ratio of the alkali to the compound (3) is 1:1.0-1: 4.0; or the molar ratio is 1:2.0-1: 3.0.
In some embodiments, the base may be an aqueous base solution; the concentration of the alkali aqueous solution is 1.0mol/L-2.0 mol/L.
In some embodiments, the post-processing comprises: stopping the reaction, cooling to room temperature, removing the solvent, adding a hydrochloric acid aqueous solution, cooling to below 10 ℃, separating out a solid, performing suction filtration, washing a filter cake with water, and performing vacuum drying to obtain a compound (4); or the post-processing comprises: stopping reaction, cooling to room temperature, removing the solvent, adding a hydrochloric acid solution, cooling to below 10 ℃, separating out a solid, performing suction filtration, washing a filter cake with water, and performing vacuum drying at 60-100 ℃ for 12-24 hours; compound (4) is obtained.
In some embodiments, the compound (3) is reacted in a methanol solution of sodium methoxide at 40-100 ℃, then an aqueous solution of sodium hydroxide is added for continuous reaction, after the reaction is finished, the reaction is stopped, the temperature is reduced to room temperature, the solvent is removed, an aqueous solution of hydrochloric acid is added, the temperature is reduced to below 10 ℃, a solid is separated out, the filtration is carried out, a filter cake is washed by water, and the vacuum drying is carried out to obtain the compound (4).
In one aspect, a method of making compound (7) comprises: the compound (6) is reacted in a reaction solvent in the presence of a Lewis acid, and the compound (7) is obtained after the post-treatment,
the Lewis acid is at least one of aluminum trichloride, lithium chloride or magnesium chloride.
The compound (6) can be obtained according to the aforementioned method.
In some embodiments, the lewis acid is aluminum trichloride, lithium chloride, or magnesium chloride, or a combination thereof. The feeding molar ratio of the Lewis acid to the compound (6) is 1:1.0-1: 4.0; or the molar ratio is 1:2.0-1: 3.0.
In some embodiments, the reaction solvent is selected from at least one of DMF, DMAC, DMSO, or NMP; in some embodiments, the reaction solvent is DMF, which facilitates the reaction.
In some embodiments, the post-processing comprises: stopping reaction, cooling to room temperature, adding dilute hydrochloric acid, precipitating solid, performing suction filtration, adding water, acetone, sodium hydroxide and active carbon into a filter cake, continuing to react at 40-80 ℃, performing suction filtration, adding concentrated hydrochloric acid into filtrate for crystallization, cooling to room temperature, performing suction filtration, and performing vacuum drying to obtain the compound (7).
In some embodiments, compound (6) is added with aluminum trichloride in DMF to react at 60-120 ℃, and after the reaction is finished, the reaction is stopped, and after post-treatment, compound (7) is obtained; the post-treatment is to stop the reaction, cool to room temperature, add dilute hydrochloric acid, separate out solid, pump filter, add water, acetone, sodium hydroxide and active carbon to the filter cake, continue to react at 40-80 ℃, pump filter, add concentrated hydrochloric acid to the filtrate for crystallization, cool to room temperature, pump filter, vacuum dry to obtain the compound (7).
In another aspect of the present invention, there is provided a compound having the structure represented by compound (4):
the compound (6) can be prepared quickly and conveniently through the compound (4), which is beneficial to simplifying the reaction process, improving the yield, reducing the cost and facilitating the industrialized production.
The preparation method of the vatacostat intermediate provided by the invention can obtain the intermediate compound (6), the compound (6) is further hydrolyzed to obtain the vatacostat, the purpose of the invention is achieved, the reaction route is short, the yield is high, the raw materials are simple and easy to obtain, the cost is lower, the reaction condition temperature is controllable, and the preparation method is suitable for industrial scale-up production.
In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
In the present invention, the expression "compound A" and "compound represented by formula A" and "formula A" means the same compound.
Detailed Description
In order to make the technical solutions of the present invention better understood by those skilled in the art, some non-limiting examples are further disclosed below, and the present invention is further described in detail.
The reagents used in the present invention are either commercially available or can be prepared by the methods described herein.
In the present invention, mmol means mmol; min represents minutes; h represents an hour; g represents g; ml means ml; DMF for N, N-dimethylformamide, THF for tetrahydrofuran; CDI represents N, N' -carbonyldiimidazole; EDCI represents 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide; DCC denotes dicyclohexylcarbodiimide; DCM represents dichloromethane; PyBOP represents benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate; DIPEA represents N, N-diisopropylethylamine; TEA represents triethylamine; DMAP represents 4-dimethylaminopyridine; DABCO represents triethylenediamine; DMSO represents dimethyl sulfoxide; DMAC represents N, N-dimethylacetamide; NMP stands for N-methylpyrrolidone.
EXAMPLE 1 preparation of Compound (4)
Adding 0.15kg of compound (3), 1.5L of anhydrous methanol and 0.22kg of sodium methoxide methanol solution (27.5% -31.0%) into a reaction bottle at room temperature, completely heating and carrying out reflux reaction, adding 1.5L of water and 0.06kg of sodium hydroxide after HPLC (high performance liquid chromatography) results show that raw materials are completely reacted, continuously carrying out reflux reaction after the HPLC results show that the raw materials are completely reacted, stopping reaction, concentrating to be dry, adding 0.21kg of concentrated hydrochloric acid for crystallization, cooling to 10 ℃, carrying out suction filtration, and drying a filter cake at 80 ℃ for 14.0h to obtain 128.5g of solid, wherein the yield is 80.9%, and the purity is 97.2%.
MS:[M+1]264.0 nuclear magnetic resonance1H NMR(400MHz,DMSO)δ8.49(s,1H),7.94(s,1H),7.86(s,1H),7.80(s,1H),7.54(s,2H),3.97(s,3H).
EXAMPLE 2 preparation of Compound (4)
Adding 0.25kg of compound (3), 2.5L of anhydrous methanol and 0.36kg of sodium methoxide methanol solution (27.5% -31.0%) into a reaction bottle at room temperature, completely heating and carrying out reflux reaction, adding 2.5L of water and 0.10kg of sodium hydroxide after HPLC (high performance liquid chromatography) results show that raw materials completely react, continuously carrying out reflux reaction after the HPLC results show that the raw materials completely react, stopping reaction, concentrating to be dry, adding 0.35kg of concentrated hydrochloric acid for crystallization, cooling to 10 ℃, carrying out suction filtration, and drying a filter cake at 80 ℃ for 14.0h to obtain 219.5g of solid, wherein the yield is 82.9%, and the purity is 98.1%.
MS:[M+1]264.0 nuclear magnetic resonance1H NMR(400MHz,DMSO)δ8.49(s,1H),7.94(s,1H),7.86(s,1H),7.80(s,1H),7.54(s,2H),3.97(s,3H).
EXAMPLE 3 preparation of Compound (6)
Adding 100.0g of the compound (4), 122.99g of CDI and 500.0ml of DCM into a reaction bottle at room temperature, stirring for reaction at 30 ℃ until the HP LC result shows that the raw materials completely react, adding 66.66g of glycine methyl ester shown as the compound (5) into the reaction bottle, continuing stirring for reaction at 30 ℃ until the HPLC result shows that the raw materials completely react, concentrating until the raw materials are dried, adding 0.95L of water for crystallization, performing suction filtration at room temperature, and drying a filter cake at 80 ℃ for 12 hours to obtain 124.2g of solid, wherein the yield is 97.8% and the purity is 97.3%.
MS:[M+1]Nuclear magnetism of 335.11H NMR(400MHz,DMSO)δ8.79(t,J=5.9Hz,1H),8.52(s,1H),7.96(s,1H),7.86(s,1H),7.82(d,J=7.0Hz,1H),7.61–7.51(m,2H),4.03(d,J=6.0Hz,2H),3.96(s,3H),3.67(s,3H).
EXAMPLE 4 preparation of Compound (6)
Adding 0.25kg of the compound (4), 0.31kg of CDI and 1.25L of DCM into a reaction bottle at room temperature, stirring for reaction at 30 ℃ until HPLC results show that the raw materials completely react, adding 0.17kg of glycine methyl ester shown as the compound (5) into the reaction bottle, continuing stirring for reaction at 30 ℃ until HPLC results show that the raw materials completely react, concentrating until the raw materials are dried, adding 2.5L of water for crystallization, performing suction filtration at room temperature, and drying a filter cake at 80 ℃ for 12 hours to obtain 311.4g of solid, wherein the yield is 98.1% and the purity is 97.2%.
MS:[M+1]Nuclear magnetism of 335.11H NMR(400MHz,DMSO)δ8.79(t,J=5.9Hz,1H),8.52(s,1H),7.96(s,1H),7.86(s,1H),7.82(d,J=7.0Hz,1H),7.61–7.51(m,2H),4.03(d,J=6.0Hz,2H),3.96(s,3H),3.67(s,3H).
EXAMPLE 5 preparation of Compound (7)
20.0g of Compound (6), 80.0ml of DMF, 9.56g of AlCl were added to a reaction flask at room temperature3Heating to 85 ℃, carrying out heat preservation reaction until HPLC results show that the raw materials completely react, stopping the reaction, cooling the reaction liquid to 30 ℃, dropwise adding 200ml of dilute hydrochloric acid for crystallization, carrying out suction filtration at room temperature, adding the filter cake into another reaction bottle, then adding 200.0ml of water, 60.0ml of acetone, 4.78g of sodium hydroxide and 2.0g of activated carbon, heating to 60 ℃ after the completion of the addition, carrying out heat preservation reaction for 1.0h, carrying out suction filtration on the reaction liquid to obtain a filtrate, dropwise adding 18.15g of concentrated hydrochloric acid into the filtrate for crystallization, cooling to room temperature, carrying out suction filtration to obtain a white-like solid, and drying at 80 ℃ for 16h to obtain 15.50g of the finished compound (7), wherein the yield is 84.70% and the purity is 99.9%.
MS:[M+1]307.0 nuclear magnetism1H NMR(400MHz,DMSO)δ12.37(s,1H),9.35(t,J=5.6Hz,1H),8.82–8.39(m,1H),7.93(d,J=24.3Hz,1H),7.85–7.68(m,2H),7.65–7.44(m,2H),4.12–3.95(m,2H).
EXAMPLE 6 preparation of Compound (7)
100.0g of Compound (6), 400.0ml of DMF, 47.80g of AlCl were added to a reaction flask at room temperature3Heating to 85 ℃, carrying out heat preservation reaction until HPLC results show that the raw materials completely react, stopping the reaction, cooling the reaction liquid to 30 ℃, dropwise adding 1.0L of dilute hydrochloric acid for crystallization, carrying out suction filtration at room temperature, adding a filter cake into another reaction bottle, then adding 1.0L of water, 0.3L of acetone, 23.90g of sodium hydroxide and 10.0g of activated carbon, heating to 60 ℃, carrying out heat preservation reaction for 1.0h, carrying out suction filtration on the reaction liquid to obtain a filtrate, dropwise adding 90.76g of concentrated hydrochloric acid into the filtrate for crystallization, cooling to room temperature, carrying out suction filtration to obtain a white-like solid, and drying at 80 ℃ for 16h to obtain 78.1g of a finished product compound (7), wherein the yield is 85.2% and the purity is 99.9%.
MS:[M+1]307.0 nuclear magnetism1H NMR(400MHz,DMSO)δ12.37(s,1H),9.35(t,J=5.6Hz,1H),8.82–8.39(m,1H),7.93(d,J=24.3Hz,1H),7.85–7.68(m,2H),7.65–7.44(m,2H),4.12–3.95(m,2H).
EXAMPLE 7 preparation of Compound (7)
Adding 5.0g of compound (6), 50.0ml of DMAC, 3.80g of LiCl and 15.43g of p-toluenesulfonic acid into a reaction bottle at room temperature, heating to 100 ℃, carrying out heat preservation reaction, stopping the reaction after HPLC (high performance liquid chromatography) results show that raw materials completely react, cooling reaction liquid to 30 ℃, dropwise adding 50ml of dilute hydrochloric acid for crystallization, carrying out suction filtration at room temperature, adding filter cakes into another reaction bottle, adding 50.0ml of water, 15.0ml of acetone, 1.19g of sodium hydroxide and 0.5g of activated carbon, heating to 60 ℃, carrying out heat preservation reaction for 1.0h, carrying out suction filtration to obtain filtrate, dropwise adding 4.54g of concentrated hydrochloric acid for crystallization, cooling to room temperature for suction filtration to obtain white-like solid, drying at 80 ℃ for 16h to obtain 3.5g of finished compound (7), wherein the yield is 76.4% and the purity is 99.1%.
MS:[M+1]307.0 nuclear magnetism1H NMR(400MHz,DMSO)δ12.37(s,1H),9.35(t,J=5.6Hz,1H),8.82–8.39(m,1H),7.93(d,J=24.3Hz,1H),7.85–7.68(m,2H),7.65–7.44(m,2H),4.12–3.95(m,2H).
While the methods of the present invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and modifications of the methods and applications described herein, as well as other suitable variations and combinations, may be made to implement and use the techniques of the present invention within the context, spirit and scope of the invention. Those skilled in the art can modify the process parameters appropriately to achieve the desired results with reference to the disclosure herein. It is expressly intended that all such similar substitutes and modifications which would be obvious to those skilled in the art are deemed to be included within the invention.