Solid-phase preparation of a pilot library derived from the 2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-amine scaffold

A convenient and reliable solid-phase strategy for the synthesis of di- and trisubstituted benzazepine derivatives was developed. 5-Amino-1-tert-butoxycarbonyl-2,3,4,5-tetrahydro-1H-benzo[b]azepine and 5-amino-1-tert-butoxycarbonyl-7-bromo-2,3,4,5-tetrahydro-1H-benzo[b]azepine G-protein coupled receptor-targeted (GPCR-targeted) scaffolds were efficiently synthesized in a six-step solution-phase process, immobilized on the acid-labile FMPB-AM resin, and further functionalized through acylation, sulfonation, reductive amination, alkylation, and Suzuki or Buchwald-Hartwig cross-coupling reactions. The efficacy of this strategy was exemplified by the preparation of an original pilot library of di- and trisubstituted benzazepines obtained in high purity as assessed by both H-1 NMR and liquid chromatography/mass spectrometry (LC/MS) analysis.