Synthesis and biological activities of novel 1,4-bridged bis-1,2,4-triazoles, bis-1,3,4-thiadiazoles and bis-1,3,4-oxadiazoles

摘要

The terephthalic acid hydrazide (1) reacted with phenyl / benzyl isothiocyanate 2a,b to yield the corresponding bis-thiosemicarbazides 4a,b, via acid hydrolysis of the intermediate 3 whereas cyclization of 4 gave the bis-1,2,4-triazoles 5,6 and bis-1,3,4-thiadiazoles 7,8. Similarly, compound 1 reacted with phenyl isocyanate 9 to give the bis-semicarbazide 10, which was cyclized to the bis-oxadiazole 11 and/or bis-1,2,4-triazole 12 in POCl3 and NaOH respectively,