Reaction #1904083

Reaction equation

Ethyl acetate

ammonium chloride

7-bromo-5-methyl-5-thien-2-yl-1,5-dihydro-4,1-benzoxazepin-2(3H)-one

lithium aluminum hydride

→

7-bromo-5-methyl-5-thien-2-yl-1,2,3,5-tetrahydro-4,1-benzoxazepine

Yield 85.0%

Solvents

THF

Conditions

Workup

1. 1
   workup.ADDITIONAfter addition
2. 2
   OtherOrganic layer was separated
3. 3
   Dryingdried (MgSO4)
4. 4
   Concentrationconcentrated

Procedure

To a solution of 7-bromo-5-methyl-5-thien-2-yl-1,5-dihydro-4,1-benzoxazepin-2(3H)-one (5 g, 14.6 mmol) in anhydrous THF (100 mL) was added lithium aluminum hydride (0.2 g, 5.2 mmol) at rt under nitrogen. After addition, the mixture was stirred for 3 hrs and treated with aqueous ammonium chloride solution (200 mL). Ethyl acetate (300 mL) was added. Organic layer was separated, dried (MgSO4), and concentrated to afford 7-bromo-5-methyl-5-thien-2-yl-1,2,3,5-tetrahydro-4,1-benzoxazepine as an oil (4 g, 85%). A white solid as a HCl salt: 1H NMR (DMSO-d6): δ 7.52 (dd, J=5.0, 0.8 Hz, 1H), 7.31 (dd, J=8.5, 2.1 Hz, 1H), 7.12 (d, J=2.1 Hz, 1H), 6.95-7.04 (m, 2H), 6.78 (dd, J=3.5, 0.9 Hz, 1H), 3.61-3.85 (m, 4H), 3.12 (m, 2H), 2.93 (s, 3H); MS (ESI) m/z 324/326 ({M+H]+); Anal. calcd for C14H14BrNOS HCl: C, 46.62; H, 4.19; N, 3.88. Found: C, 46.70; H, 3.99; N, 3.83.

Source