الفهرس | Only 14 pages are availabe for public view |
Abstract A number of substituted dihydropyrimidine and 1,3,4-oxadiazole based pyrimidine nucleus as their as their sugar derivatives were synthesized. 1,3-bis(4-bromophenyl)-2,3-epoxypropanone (2) was prepared by treatment of 1,3-bis(4-bromo phenyl) propenone (1) with hydrogen peroxide in alkaline medium. Reaction of 2 with thiourea in alcoholic potassium hydroxide, produced the tetrahydropyrimidin-5-one derivative 3 Reaction of 3 with 2,3,4-tri-O-acetyl-D-xylopyranoside afforded the thioxylosyl derivative 4Deacetylation of the O-acetyl thioglucoside 4 afforded the free thioglycosidederivative 5Compound 2 was reacted with urea and/or thiosemicarbazide to give the substituted tetrahydropyrimidine derivatives 6 and 7, resThe thiazolo[3,2-a]pyrimidine-3,6-dione 8 was prepared by reacting 3 with chloroacetic acid in acetic acid / acetic anhydride mixture. Thethiazolo[3,2-a] pyrimidine-3,6-dione 9 was directly prepared from compound 3 in one step by heating with chloroacetic acid and benzaldehyde in acetic acid/acetic anhydride mixture in the presence of sodium acetate. Compound 9 was also prepared from compound 8 by reaction with benzaldehyde |