Pyridine → 7-bromo-2,3-dihydro-1,4-benzoxazepine-4(5H)-carbonyl chloride

Beteiligte Stoffe

Reaktionsschritte

7-bromo-2,3,4,5-tetrahydro-1,4-benzoxazepine hydrochloride (3.0 g, 11.34 mmol) was suspended in dichloromethane (30 mL) followed by addition of DIPEA (3 mL, 34 mmol) and pyridine (4 mL, 49 mmol) and the resulting partially heterogeneous mixture was added portionwise over 5 minutes to a 0° C. cooled solution of phosgene (20 W % in toluene, 15 mL, 28 mmol) in dichloromethane (15 mL). The resulting mixture was then allowed to slowly warm to room temperature over 30 minutes then concentrated. The residue was partitioned with ethyl acetate and water and the organic phase washed twice with 1M aqueous hydrochloric acid then brine, dried over anhydrous magnesium sulfate, filtered and concentrated to give 7-bromo-2,3-dihydro-1,4-benzoxazepine-4(5H)-carbonyl chloride (3.35 g) as a pale yellow oil. MS (EI) for C10H9BrClNO2: 292 (MH+).

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