Bilane

Bilane
Names
	IUPAC name 5,10,15,22,23,24-Hexahydro-21H-biline
	Systematic IUPAC name 11H,31H,51H,71H-1,7(2),3,5(2,5)-Tetrapyrrolaheptaphane
	Other names Bilinogen; Tetrapyrrolotrismethane
Identifiers
CAS Number	68277-11-2;
3D model (JSmol)	Interactive image;
Beilstein Reference	8008279
ChEBI	CHEBI:36305;
ChemSpider	7827700;
PubChem CID	9548777;
CompTox Dashboard (EPA)	DTXSID401336226 ;
	InChI InChI=1S/C19H20N4/c1-3-14(20-9-1)11-16-5-7-18(22-16)13-19-8-6-17(23-19)12-15-4-2-10-21-15/h1-10,20-23H,11-13H2 Key: AXMKEYXDFDKKIO-UHFFFAOYSA-N;
	SMILES C1=CNC(=C1)CC2=CC=C(N2)CC3=CC=C(N3)CC4=CC=CN4;
Properties
Chemical formula	C19H20N4
Molar mass	304.397 g·mol−1
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

In organic chemistry, bilane is a compound with the formula C₁₉H₂₀N₄ or [(C₄H₄N)−CH₂−(C₄H₃N)−]₂CH₂. It is a tetrapyrrole, a class of compounds with four independent pyrrole rings. Specifically, the molecule can be described as four pyrrole molecules C₄H₅N connected in an open chain by three methylene bridges −CH₂− at carbons adjacent to the nitrogens, replacing the respective hydrogens.^[1]

The name is also used for the class of compounds formally derived from bilane proper by replacement of some additional hydrogen atoms by various functional groups. Natural bilanes usually have side chains substituted on the two carbons in each pyrrole ring that are not adjacent to the nitrogens. Artificial bilanes may be substituted on the bridging carbons (called meso positions).^[2]

The parent (unsubstituted) bilane is difficult to prepare and unstable,^[3] but substituted derivatives are synthesized by most living organisms as intermediates in the synthesis of natural porphyrins. Substituted bilanes may also be the starting point for the synthesis of artificial porphyrins.^[2]^[3]

Reactions

Upon treatment with aldehydes, bilanes may cyclize to give porphyrinogens and various open or closed oligomers and polymers.^[2]

In living organisms, the biosynthesis of all natural porphyrins proceeds through the bilane preuroporphyrinogen, which is produced from four molecules of the monomer porphobilinogen, and then converted to the closed tetrapyrrole uroporphyrinogen III (or, in certain metabolic disorders, into uroporphyrinogen I). Also, the catabolism of hemoglobin in humans produces bilirubin, another linear tetrapyrrole that is a partially oxidized bilane.

References

^ Gerard P. Moss (1988). "Nomenclature of Tetrapyrroles. Recommendations 1986". European Journal of Biochemistry. 178 (2): 277–328. doi:10.1111/j.1432-1033.1988.tb14453.x. PMID 3208761.
^ ^a ^b ^c Lindsey, J. S. (2010). "Synthetic Routes to meso-Patterned Porphyrins". Accounts of Chemical Research. 43 (2): 300–311. doi:10.1021/ar900212t. PMID 19863076.
^ ^a ^b Claudia Ryppa, Mathias O. Senge, Sabine S. Hatscher, Erich Kleinpeter, Philipp Wacker, Uwe Schilde, and Arno Wiehe (2005): "Synthesis of Mono- and Disubstituted Porphyrins: A- and 5,10-A₂-Type Systems". Chemistry, A European Journal, volume 11, issue 11, pages 3427-3442. doi:10.1002/chem.20050000

[1] Gerard P. Moss (1988). "Nomenclature of Tetrapyrroles. Recommendations 1986". European Journal of Biochemistry. 178 (2): 277–328. doi:10.1111/j.1432-1033.1988.tb14453.x. PMID 3208761.

[lindsey-2] Lindsey, J. S. (2010). "Synthetic Routes to meso-Patterned Porphyrins". Accounts of Chemical Research. 43 (2): 300–311. doi:10.1021/ar900212t. PMID 19863076.

[ryppa-3] Claudia Ryppa, Mathias O. Senge, Sabine S. Hatscher, Erich Kleinpeter, Philipp Wacker, Uwe Schilde, and Arno Wiehe (2005): "Synthesis of Mono- and Disubstituted Porphyrins: A- and 5,10-A₂-Type Systems". Chemistry, A European Journal, volume 11, issue 11, pages 3427-3442. doi:10.1002/chem.20050000

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