Carbon oxysulphide: A novel reagent for the synthesis of 4-amino/anilino-3-aryl/aryloxymethyl/thiophenoxymethyl-1,2,4-triazolin-5-ones and 5-arylamino-2-mercapto-1,3,4-oxadiazoles

摘要

Acid hydrazides 1 on reaction with carbon oxysulphide in the presence of alcoholic KOH afford potassium #beta#-acylthiocarbazinates 2 which on further reaction with hydrazine hydrate or phenylhydrazine give 4-amino-3-substituted-1,2,4-triazolin-5-ones 3 and 4-anilino-3-substituted-1,2,4-triazolin-5-ones 5 respectively. 4-Substituted thiosemicarbazides 6 on treatment with carbon oxysulphide in the presence of alc NaOH afford sodium #beta#-(N-arylthiocarbamyl)thiocarbazinates 7 which on cyclisation in the presence of ethanolic NaOH afford 5-arylamino-2-mercapto-1,3,4-oxadiazoles 8. On reaction with benzyl chloride in the presence of NaOH 8 isomerise to 3-benzylmercapto-4-substituted-1,2,4-triazolin-5-ones 9.