Abstract
Syntheses of nucleoside analogs with glycosyl isothiocyanates (1a,b,c) are reported. Reaction between 1a,b,c and ethyl 3-aminocrotonate gave a mixture of glycosylaminoisothiazoles(6a,b,c) and glycosylthiocarbamoyl crotonates(7a,b,c), and the later compounds were readily cyclized to 6a,b,c. Similar reaction of 1a,b,c with 6-amino-1,3-dimethyluracil yielded glycosylaminoisothiazolo[3,4-d]-pyrimidines(8a,b,c). Reaction of 1a,b,c and diamines (o-phenylenediamine, 2,3-diaminopyridine, or 5,6-diamino-1,3-dimethyluracil) afforded glycosylthioureides(11a,b,c), followed by heating with methyl iodide to give glycosylamino-benzimidazoles(12a,b,c), -3-deazapurines(13a,b,c) or-theophyllines(14a,b,c) through a cyclode-sulfurization. Reaction of 1a,b,c with 2-hydrazinopyridine or 6-hydrazino-1,3-dimethyluracil gave glycosyl thiosemicarbazides(17 or 18a,b,c). Oxidative cyclization of 18a,b,c with NBS afforded glycosylaminopyrimido[4,5-e]-1,3,4-thiadiazines(20a,b,c), followed by heating to give glycosylaminopyrazolo[3,4-d]pyrimidines(21a,b,c). Reaction of 1a with hydrazinocarbonyl compounds and hydrazino compounds gave glycosyl thiosemicarbazides(22a,30a). Treatment of the former with PPA gave glycosyl-1,2,4-trizolin-3-one(28a) and that of the later with phosgene yielded glycosyl 1,3,4-thiadiazolone(33a). Methylation of 30a with methyl iodide gave glycosyl-S-methylthiosemicarbazide(31a), followed by treatment with phosgene to give glycosyl-5-thio-1,2,4-triazolin-3-one(32a). Reaction of 1a with thiourea in the presence of methyl iodide gave glycosyl isobiuret (36a), which is an useful intermediate for nucleoside analogs. Treatment of 36a with triethyl orthoformate yielded s-triazine glycoside(37a).
