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Synthesis of 5‐substituted 2‐(2,4‐dihydroxyphenyl)‐1,3,4‐thiadiazoles

“…The cyclization process is conditioned by proper acidity of -C(=S)NHmoiety proton and induced by -OH groups size of potential on the sulfur atom. The proposed mechanism is similar to that described by Golovlyova et al for acylthiosemicarbazides [7].…”

Thiadiazoles

“…This cyclization is quite general and other dehydrating agents have been used such as polyphosphoric acid [283] and phosphorus oxychloride [284].…”

The chemistry of mercapto- and thione- substituted 1,2,4-triazoles and their utility in heterocyclic synthesis

“…The reaction of carboxylic acid chlorides 1 and thiosemicarbazide gave 2, which without purification were cyclized in alkaline media to yield the corresponding 2,4-dihydro-3H--1,2,4-triazole-3-thiones 3 [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] …”