Studies in pyrolysis. Part XXIII. Competitive routes in the pyrolysis of 1-anilino-cis- and -trans-2-methylcyclohexane-1-carbonitrile, and 1-benzoyloxy-cis- and -trans-2-methylcyclohexane-1-carbonitrile

Abstract

The assignment of cis- and trans-(Me : CN)structures throughout is established. The cis- and trans-anilinonitriles break down (liquid phase, ca. 200–250°; vapour phase, ca. 500°) by reversible primary dissociation into hydrogen cyanide and the corresponding anil. No competing scission to aniline and olefinic nitrile occurs but the anil undergoes some further partial self-condensation, with elimination of aniline. The cis- and trans-cyanoesters break down mainly by A¹ scission to benzoic acid and a mixture of 2- and 6-methylcyclohexene-1-carbonitrile; cis-elimination predominates (Saytzeff : Hofmann ratio ca. 67 : 33 from cis-ester, ca. 3.5 : 96.5 from trans-ester; vapour phase, ca. 500°). There is a minor competitive B² scission to 2-methylcyclohexanone and benzoyl cyanide. The corresponding cis- and trans-cyanohydrins are described and their dehydration is discussed.