Hydrochloric Acid → 7-Bromo-5-(2-fluoro-phenyl)-3-methyl-1,3-dihydro-benzo[e][1,4]diazepin-2-one

Participants

Reaction Steps

To a stirred solution of the benzophenone 136 (30 g, 64.4 mmol) in CHCl3 (300 mL) at rt, hydrogen chloride gas was added slowly. After 20 min, the addition was stopped and the solution was allowed to stir overnight at rt. The reaction mixture was then washed with a saturated solution of sodium bicarbonate (2×70 mL) and water (2×70 mL). The organic layer was concentrated under reduced pressure. The residual oil was dissolved in methanol-water (1:1, 300 mL) and the pH was adjusted to 8.5 by the addition of aq sodium hydroxide (1 N). The reaction mixture was allowed to stir for 10 h at rt. The solution was then concentrated under reduced pressure and water (100 mL) was added. The solution was extracted with CH2Cl2 (3×50 mL), and the organic layer was dried (Na2SO4) and concentrated under reduced pressure. The crude solid 137 was purified by recrystallization from methanol/water to provided 137 (18.2 g, 82%). mp 183-185° C.; IR (KBr, cm−1) 2928, 1694, 1611, 1479, 1450, 1377, 1315; 1H NMR (CDCl3) δ 9.50 (bs, 1 H), 7.62-7.65 (m, 2 H), 7.50 (q, J=6.5 Hz, 1H), 7.40 (d, J=2.0 Hz, 1 H), 7.29 (t, J=7.5 Hz 1 H) 7.15 (d, J=8.6 Hz, 1 H), 7.11 (t, J=8.9 Hz, 1 H), 3.84 (q, J=6.5 Hz, 1 H), 1.82 (d, J=6.5 Hz, 3 H); MS (EI) m/e (relative intensity) 348 (M++1, 23), 347 (M+, 38), 346 (24), 345 (36), 329 (19), 327 (20), 307 (40), 306 (41), 305(100), 304 (37), 303 (63); [α]26D=−169.1 (c 0.71, EtOAc).

Provenance & Evidence