Abstract
[GRAPHICS]
A synthesis of novel three-, four-, and sixfold branched 4-phenylthiazolylhydrazones, 4-pyrazolylthiazolyl hydrazones, and thiadiazoles which are linked to a benzene core via phenoxymethyl spacers was reported. The synthetic methodology includes initially formation of poly( aldehyde thiosemicarbazones) 9, 14, and 15 by acid catalyzed condensation of thiosemicarbazide ( 8) with the appropriate poly( aldehydes) 3, 5, and 7, respectively. Subsequent reaction of 9, 14, and 15 with each of 2-bromo-1-phenylethanone ( 10a) and 2-bromo-1-(4chlorophenyl) ethanone ( 10b) in refluxing ethanol in the presence of few drops of TEA afforded 11, 16, and 18, respectively, in good yields. On the other hand, the synthesis of the novel poly( 4,5-dihydro-1,3,4-thiadiazolyl) derivatives 20, 21a, b, and 22 was performed by cyclization of 9b, 14a, b, and 15a, respectively, in refluxing acetic anhydride.