A Novel and Facile Synthesis of Thiopyrimidines and O-Glucosides

Reaction of 3-methyl-5-(3'-aryl prop-2'-enoyl)-1,2-benzisoxazole (1a-j) with thiourea and alcoholic solution of KOH afforded 3-methyl-5-(4'-aryl-2'-thiopyrimidin-6'-yl)-1,2-benzisoxazoles (2a-j). Oxidation of products 2a-j using alkaline KMnO4 solution produces 5-(4'-aryl-2'-thiopyrimidin-6'-yl)-1,2-benzisoxazole-3-carboxylic acids (3a-j). Condensation of products 3a-j with 2,3,4,6-tetra-Oacetyl-α-D-glucopyranosyl bromide (TAGBr), the glucosylating agent synthesized 3-(2,3,4,6-tetra-O-acetyl-3-acetyl-β-D-glucopyranosyl)-5-(4'-aryl-2'-thiopyrimidin-6'-yl)-1,2-benzisoxazoles (4a-j). Subsequent deacetylation of compounds 4a-j were carried out with CH3ONa furnishes β-Dglucopyranosyl-5-(4'-aryl-2'-thiopyrimidin-6'-yl)-1,2-benzisoxazole-3-carboxylates (5a-j). All the synthesized compounds were analyzed by elemental analysis (C, H and N), FT-IR, 1H NMR and mass spectral data. Most of the prepared compounds were analyzed their antibacterial and antifungal activities by cup-plate method. The present approach offers several advantages such as shorter reaction times, cleaner reactions, good yields, low-cost reagent and mild reaction conditions.