Acyl derivatives of 2,3,6,7-tetrahydro-1,4-diazepines: synthesis, structure, and tautomeric transformations

Abstract

The reaction of 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene with carboxylic acid chlorides afforded a series of N -and C -acylsubstituted 2,3,6,7-tetrahydro-1,4-diazepines, which in solutions of deuterated solvents (CD3OD, DMCO) undergo keto-enol and imino-enamine tautomerism. Structure of the obtained N - and C -acyldiazepines and their tautomeric transformations were characterized by 1Н and 13С NMR spectroscopy using two-dimensional experiments 1Н-13С HMQC, HMBC, 1Н-1Н COSY.