A NON-ACYL AZIDE ROUTE TO ISOQUINOLIN-1(2H)-ONE DERIVATIVES VIA beta-STYRIL CARBAMATES

Abstract

The efficient reactions of the phenyl acetaldehydes la-e and the enol ethers of benzyl ketones 1o-s with ethyl urethane lead to the formation of the beta-styril carbamates 2, which are excellent precursors for generating isoquinolin-1(2H)-ones 4. Upon thermolysis at 230 degrees C in an inert organic solution, the carbamates decomposed into the transient beta-styril isocyanate intermediates 3. The resulting isoquinolin-1(2H)-ones obtained were in good yields (65-93%). This synthetic methodology allows the convenient preparation of isoquinolin-1 (2H)-ones via a non-phosgene and non-acyl azide route from readily accessible starting materials.