Borane → 2,3,4,5-Tetrahydro-1,5-benzoxazepine

Participants

Reaction Conditions

Reaction Steps

6,7-Dihydro-9H-5-oxa-9-aza-benzocyclohepten-8-one (0.13 g, 0.8 mmol) was dissolved in THF and to this solution was added a 1M solution of borane in THF (1.59 mL, 1.6 mmol). The mixture was heated at 70° C. for 2 hrs. At this time a further portion of borane solution (1.59 mL, 1.6 mmol) was added and heating was continued for another 2 hrs. The solvent was evaporated at this point and the residue was dissolved in ethyl acetate. Extraction of the solution with 1M sodium hydroxide solution and then brine afforded an organic layer that was dried over anhydrous sodium sulfate. The filtrate was evaporated to afford 6,7,8,9-tetrahydro-5-oxa-9-aza-benzocycloheptene 2-4 (0.15 g, 100%) that was used without further purification. MS: 150.0 (M+H)+; tR=0.57 min (method 1).

Provenance & Evidence