Ammonium Chloride → 7-bromo-1H,2H,3H,5H-pyrido[2,3-e][1,4]oxazepine

Participants

Reaction Conditions

Reaction Steps

3-Bromo-5,9-dihydro-6-oxa-1,9-diaza-benzocyclohepten-8-one (205 mg, 0.84 mmol) and sodium borohydride (160 mg, 4.2 mmol) are dissolved in 1.0 mL of THF and the mixture is cooled down to 0° C. Neat BF3 Et2O (0.74 mL, 5.9 mmol) is added dropwise and the mixture is stirred for 3 hr at room temperature. Then saturated aqueous NH4Cl solution (15 mL) is added carefully and the mixture is further basified by adding solid NaHCO3. The mixture is then extracted with EtOAc (3×35 mL). The organic layers are combined and concentrated to give the crude product. Purification by flash column chromatography affords 78 mg of 3-bromo-5,7,8,9-tetrahydro-6-oxa-1,9-diaza-benzocycloheptene

Provenance & Evidence