Thirteen N,N‐diazolylmethanes, including derivatives of pyrazole, imidazole, 1,2,4‐triazole, benzimidazole and indazole were prepared by reaction of azoles with methylene chloride under phase transfer catalysis conditions. The relative amounts of isomeric mixtures obtained with ‘asymmetric’ azoles or with equimolar mixtures of azoles are compared with literature results on monoalkylation of azoles. Proton and carbon‐13 nmr spectra of the N,N'‐diazolylmethanes are discussed.

The NMR variable temperature behaviour of a series of N-aryl-N-benzyl alkyl carbamates was investigated. The barrier to rotation about the N-aryl bond was determined for all the compounds studied. The values obtained, which are in good agreement with those found for structuraUy related N-aryl-N-benzylamides, are in the range AG' = 60.7-89.6 kJ mol-'. For some carbamates another confonnational phenomenon has been observed, namely the hindered rotation about the carbonyl carbon-nitrogen bond, with a barrier to rotation corresponding to reported values for similar systems.

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