Multicomponent Synthesis of Novel 2- and 3-Substituted Dihydrobenzo[1,4]oxazepinones and Tetrahydrobenzo[1,4]diazepin-5-ones and Their Conformational Analysis

- By coupling an Ugi multicomponent condensation with a Mitsunobu reaction, a series of 2- and 3-substituted dihydrobenzo[l,4]oxazepinones and tetrahydrobenzo[1,4]diazepin-5-ones was synthesized in a very convergent manner. The strategy involves the use of substituted ethanolamines as amino components and of salicylic or N-methanesulphonyl anthranilic acid as carboxylic component. The general scope has been evaluated; in some cases better results have been obtained by reverting the order of the two reactions. A thorough conformational analysis on these products has been carried out through NMR, showing that in most cases a single conformation was strongly favoured.