Boron tribromide → HCID 178423903, compound

Participants

Reaction Steps

To a stirred suspension of 3-methoxy-9-methyl-1H-1-benzazepine-2,5-dione (39, 200 mg, 921 μmol) in dry CH2Cl2 (2 mL, distilled from CaH2) under N2, there was added a solution of BBr3 in CH2Cl2 (2 mL, 1M, Aldrich) in one portion at rt. The reaction instantaneously became homogeneous and yellow, then a yellow precipitate formed after a few seconds. The reaction was allowed to stir under N2 at rt for 45 min. The reaction was added to saturated NaHCO3 (15 mL) and the resulting beige suspension was allowed to stir for 15 min to give a cloudy, orange solution. The solution was filtered through glass wool to remove any suspended matter. The resulting solution was acidified with concd HCl (pH 2), the solid collected by filtration and washed to neutrality with water (5×2 mL). The damp filter cake was crystallized from 95% EtOH (dissolved in 15 mL, hot filtered, concd to 7 mL) to yield 43 as brown needles (98 mg, 52%, pure by TLC, 1H NMR and C,H,N analyses); mp 184°-185.5° C. (EtOH), 1H NMR (DMSO-d6) δ2.46 (s, 3H), 6.28 (s, 1H), 7.19 (t, J=7.5 Hz, 1H), 7.53 (d, J=7.2 Hz, 1H), 8.03 (d, J=7.8 Hz, 1H), 9.94 (s, 1H), 10.85 (bs, 1H); Anal. Calcd for C11H9NO3.0.5 H2O: C, 62.26; H, 4.75; N, 6.60. Found: C, 62.39; H, 4.53; N, 6.51.

Provenance & Evidence