Investigation of the thermolysis of 5-methyl-1-phenyltetrazole by combined derivatography and mass spectrometry

The thermolysis of 5-methyl-1-phenyltetrazole was studied at 20–350°C by derivatography and mass spectrometry, and it was shown that thermal decomposition proceeds with the elimination of a molecule of nitrogen and is accompanied by skeletal rearrangement of the intermediately formed nitrene to 2-methylbenzimidazole or migration of the methyl group to the nitrogen atom with the formation of methylphenylcarbodiimide (MPCD). In addition, symmetrical dimethyl- and diphenylcarbodiimides, methylphenylguanidines, and aniline are formed. It is assumed that the formation of these compounds in the pyrolyzate is due to polymerization of MPCD and subsequent thermal destruction of the polymerization products. A scheme for the thermolysis of 5-methyl-1-phenyltetrazole is proposed. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 265–271, February, 1980.