Reactions of asymmetric carbodiimides with azoimide

Abstract

Reaction of asymmetric aliphatic-aromatic and diaryl carbodiimides with HN 3 leads to 1,5-disubstituted tetrazoles. Carbodiimides of general formula C 6 H 5 -N=C=N-R (R = alkyl) from an adduct at C=N bond exclusively at a less basic nitrogen, i.e. near phenyl whereas those with R = aryl afford a 1 : 1 mixture of products. 1 H-NMR spectroscopy revealed an aminotetrazole-iminotetrazoline tautomerism of the prepared 1=phenyl-5-alkylaminotetrazoles, which undergo isomerization to 1-alkyl-5-anilinotetrazoles.