Me 3SiCl-promoted intramolecular cyclization of aromatic compounds tethered with N, O-acetals leading to the facile preparation of 1,4-benzodiazepine skeletons

Abstract

The Me 3SiCl-promoted intramolecular aminomethylation of a novel type of N, O-acetals, which were prepared via a facile three-step synthesis from N-alkylaniline derivatives and N-alkyl-2-oxazolidinones that leads to the production of pharmaceutically useful 1,4-benzodiazepine skeletons with a variety of functional groups is described. This method was successfully applied to the facile preparation of both tricyclic benzodiazepine derivatives and a 1,4-benzoxazepine derivative via 7- exo- trig cyclization.