Synthesis and Antimicrobial Activity of Some 2-Substituted arylamino-4-(2-naphthyl)-thiazol-5-yl-acetic acids and 2-[2-{4-(4-substituted aryl)}thiazolyl]-6-(l or 2-naphthyl)-4,5-dihydro-3(2H) pyridazinones

The condensation of 4-(1 or 2-naphthyl)-4-oxobutanoic acids with thiosemicarbazide in refluxing ethanol afforded 4-(1 or 2-naphthyl)-4-oxobutanoic acid thiosemicarbazones (1, 2) which on further condensation with phenacylbromide gave corresponding 4,5-dihydro-3(2H) pyridazinones (3–13). The reaction of 4-(2-naphthyl) butanoic acid with various substituted phenyl thioureas in refluxing ethanol, afforded corresponding-4-(2-naphthyl) thiazol-5-yl-acetic acid (14–19). These compounds were characterized and screened for their antimicrobial activity, and some of them exhibited moderate antimicrobial activity.