Abstract:

1-[5-（4-nitrobenzoy）-β-D-ribofuranosyl]-1,2,4-triazole-3-carboxamide（IIIa）,1-[5-（3,4,5-tribenzyl-oxybenzoyl）-β-D-ribofuranosyl]-1,2,4-triazole-3-carboxamide（IIIb） and 1-（5-benzoyl-β-D-ribofuranosyl）-1,2,4-triazole-3-carboxamide（IIIc） were synthesized from 1-[2,3-O-（1-methylethylidene）-D-ribofuranosyl]-1,2,4-triazole-3-carboxamide（I） through the esterification with three different acyl chloride catalyzed by base and the hydrolysis catalyzed by p-TsOH.Then,1-[5-（4-aminobenzoyl）-β-D-ribofuranosyl]-1,2,4-triazole-3-carboxamide（IVa） and 1-[5-（3,4,5-trihydroxybenzoyl）-β-D-ribofuranosyl]-1,2,4-triazole-3-carboxamide（IVb） were obtained by means of catalytic hydrogenation.Moreover,the intermediates and title compounds were confirmed by means of IR and 1H NMR,and the effects of different kinds of bases and solvents on the esterification,different kinds of acids on the deprotection reaction and Pd/C dosage on the catalytic hydrogenation were investigated.The results show that（1） the esterification,with pyridine as the acid-binding agent and the solvent,is of high yield and good selectivity,and the conversion rate is up to more than 95%;（2） p-TsOH is a suitable catalyst for the deprotection reaction with fewer by-products;and（3） the conversion becomes complete at a mass ratio of Pd/C to compound IIIa of 0.10.

Key words: ribavirin, derivative, nucleotide, catalyst