Aluminum(III) Chloride → 4,5-Dihydro-3-benzothiepin-1(2H)-one

Participants

Reaction Steps

A suspension of aluminum chloride (12.21 g, 92 mmol) in CH2Cl2 (200 mL) was treated dropwise with a solution of Example 107B (9.83 g, 45.8 mmol) in CH2Cl2 (100 mL) over 35 minutes, stirred at ambient temperature for 30 minutes, poured into a flask containing ice water (˜400 mL) and transferred to a separatory funnel using ˜50 mL CH2Cl2. The layers were separated and the aqueous was extracted with CH2Cl2 (100 mL). The combined CH2Cl2 layers were dried (MgSO4), filtered, concentrated and purified by chromatography on silica gel eluting with 20:1, 10:1 and 5:1 hexane:EtOAc to provide the title compound. 1H NMR (CDCl3) δ 2.99 (t, J=6.4 Hz, 2H), 3.19 (t, J=6.4 Hz, 2H), 3.55 (s, 2H), 7.21-7.26 (m, 1H), 7.40 (dt, J=7.6, 1.4 Hz, 1H), 7.50 (dt, J=7.5, 1.4 Hz, 1H), 7.93 (dd, J=7.8, 1.4 Hz, 1H); MS (M+H)+ m/z 179 (20%), (M+NH4)+ m/z 196 (100%).

Provenance & Evidence