Studies with Reissert compounds. Part 17. Mono-Reissert compound formation at the 1,2-position of the quinazoline system

Abstract

4-Substituted quinazolines have been selectively converted into mono-Reissert compounds at the 1,2-position by use of acid chlorides and trimethylsilyl cyanide. Various reactions of the quinazoline Reissert compounds are reported. For example, conjugate base generation at the 2-position leads to a 1,2-rearrangement, whereas substitution occurs in the presence of an alkyl halide, providing, after hydrolysis, 2-alkyl-4-phenylquinazolines in good yield. Ring annellation by intramolecular alkylation is also reported. The quinazoline Reissert compound conjugate base reacts with aldehydes to give alcohol esters which can further be converted, via the alcohol and use of phosgene, to novel oxazolo[4,3-a]quinazoline derivatives.