A novel synthetic approach to 11-substituted dibenzo[b,f][1,4]oxazepines

A novel protocol for the synthesis of 11-substituted dibenzo[b,f][1,4]oxazepines is reported. Seven compounds were designed as analogs of the antipsychotic drug loxapine and antidepressant amoxapine. The key transformations include generation of a carbamate intermediate using phenyl chloroformate which avoids the use of harmful phosgene, a microwave-induced transformation of the carbamate intermediate into various urea derivatives, and a subsequent phosphorous oxychloride-induced cyclocondensation. The simple reactions and wide substrate scope enhance the practical application of this methodology.