MOLECULAR REARRANGEMENTS OF SULFUR COMPOUNDS PART VIII. PYROLYSIS OF 2-(N-SUBSTITUTED CARBOXAMIDO-METHYLTHIO)-5-ARYLAMINO-1,3,4-THIADIAZOLE DERIVATIVES

Abstract

Pyrolysis of 2-(N-substitutedcarboxamidomethylthio)-5-arylamino-1,3,4-thiadiazoles(I-III) at ca 210°C in boiling tetralin for 8 hrs or neat at ca 250°C for 5 hrs affords hydrogen sulfide, aryl isothiocyanate, arylcyanamide, benzimidazole derivatives, 4-aryl-1,2,4-triazole, thioglycolicanilides, 4-aryl-δ²-triazoline-5-thione and 3-aryl-2-thiohydantoin derivatives. A free radical mechanism has been suggested to account for the obtained products.

Key Words:

• Molecular rearrangement
• pyrolysis
• thiadiazole derivatives