HCID 21821191, compound → Ammonia

Participants

Reaction Steps

Fusion of methyl 1,2,3-triazole-4-carboxylate prepared as in F. P. Woerner et al., Chem. Ber., 103, 1908 (1970) with 1-0-acetyl-2,3,5-tri-0-benzoyl-β-D-ribofuranose in the presence of an acidic catalyst provides a mixture of 2-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-1,2,3-triazole-5-carboxylic acid methyl ester (1) and 1-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-1,2,3-triazole-4caboxylic acid methyl ester (2) in respective ratio of about 2:1, together with a small fraction of 1-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-1,2,3-triazole-5-carboxylic acid methyl ester. The particular carboxylic acid ester group of the starting base is not critical, as its alkoxy component is split off in the following step of conversion to the bioactive carboxamide. Again, for ease of workup, lower carboxylic acid esters such as carbomethoxy or carboethoxy groups are preferred. Treatment of 1 and 2 with methanolic ammonia provides 2-β-ribofuranosyl-1,2,3-triazole-4-carboxamide (4) and 1-β-D-ribofuranosyl-1,2,3-triazole-4-carboxamide (5). The isomeric 1-β-O-ribofuranosyl-1,2,3 -triazole-5-carboxamide may be similarly obtained from 3. If desired, glycosyl hydroxyl blocking groups may be removed before conversion to the carboxamide. For example, compound 1 may be debenzoylated by reaction with sodium methoxide is methanol.

Provenance & Evidence