Synthesis of 3-[3-substitutedthio]-7H-1,2,4-triazolo [3,4-b] [1,3,4] thiadiazin-6-yl]-2H-1-benzopyran-2-ones and 3-[3-aminoaryl/heterocyclyl]-7H-1,2,4-triazolo [3,4-b] [1,3,4] thiadiazin-6-yl]-2H-1-benzopyran-2-ones

Some 3-[(3-mercapto)-7H-1,2,4-triazolo [3,4-b] [1,3,4] thiadiazin-6-yl],-2H-1-benzopyran-2-ones (3) have been prepared by the condensation of 3-(2-bromoacetyl) coumarin (1) and 3,5-dimercapto-4-amino-s-triazole (2) in anhyd ethanol. 3 on treatment with chloroacetone, allyl bromide and phenacyl chloride in dimethy1formamide gave (4). Reaction of (3) with various aromatic primary amines in dimethy1formamide gave corresponding 3-[3-aminoaryl]-7H-1,2,4-triazolo [3,4-b] [1,3,4] thiadiazin-6-yl]-2H-1-benzopyran-2-ones (5). The structures of newly prepared compounds have been confirmed on the basis of analytical and spectra data.