Reaction of 1-Aryl- , 1,3 -Diaryl- and 1-Alkyl-3-aryl -S-alkyl- isothioureas with 4-Alkyl/Aryl Thiosemicarbazides : Formation of 4-Alkyl/Aryl-3-arylamino - 5 - mercapto-1,2,4-triazoles and 2, 5-Diarylamino - 1,3,4-thiadiazoles

Department of Chemistry, University of Kerala, Trivandrum-695 034 Manuscript received 6 February 1990, revised 30 April 1990, accepted 19 June 1990 The interaction of 1-aryl-, 1,3-diaryl- and 1-alkyl-3-aryil-S-alkylisothioureas (1) with 4-alkyl/aryl thiosemicarbazides (2) has been found to afford 4-alkyl/aryl-3- arylamino-5-mercapto-1,2,4-triazoles (5) in good yield. 2,5-Diarylamino-1,3,4-thiadiazoles (6) is also formed as a minor product. A probable mechanism is suggested for the formation of these products.