Recent advances in dibenzo[b, f][1,4]oxazepine synthesis

Dibenzo[b, f][ 1,4] oxazepine (DBO) derivatives possess an array of pharmacological activities, and are of growing pharmaceutical interest. Twelve recent synthetic protocols to construct DBO and DBO derivatives have been described in this review. The reported methods include cyclocondensation with two precursors exemplified by substituted 2-aminophenols and substituted 2-halobenzaldehydes, substituted 2-nitro-1-bromobenzene and substituted 2-triazolylphenols, substituted 2-nitro-1-bromobenzene and substituted 2-hydrazonamidophenol, substituted 2-nitro-1- bromobenzene and substituted 2-(aminomethyl) phenol, and 2- aminobenzonitrile and 1,4-dichloro-2-nitrobenzene. Other methods include copper catalysis, 1,3-dipolar cycloaddition, domino elimination-rearrangement-addition sequence, and an Ugi four-component reaction followed by an intramolecular O-arylation. These methods will serve as a guide to chemists in developing DBO derivatives of pharmacological interest.