3-fluorodibenzo[b,e]oxepin-11(6H)-one → 3-Fluoro-6,11-dihydro-11-methylenedibenz[b,e]oxepin

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Reaction Steps

Cool a solution of 3-fluoro-6H-dibenzo[b,e]oxepin-11-one (prepared according to the procedure reported by M Kurokawa, F Sato, Y Masuda, T Yoshida and Y Ochi, Chem. Pharm. Bull., 1991, 39(10), 2564-5273; 11.5 g, 50.5 mmol) and THF (100 mL) to 0° C. under N2. Add dropwise MeMgBr (3.0M in Et2O, 33.7 mL, 101 mmol) this mixture. Warm to room temperature and stir overnight. Cool to 0° C. and quench very carefully (exotherm) with HCl (4.00 M in dioxane, 30 mL). Warm to room temperature and stir for 30 min. Dilute reaction mixture with water (70 mL) and extract into ethyl acetate (three 100 mL portions). Dry (MgSO4), filter, and concentrate organics to a brown solid. Purify crude product on a 100 g plug of silica gel, eluting with hexanes to afford 9.26 g (81%) of the title compound as a yellow solid. MS [EI] 226; HPLC shows 90% purity.

Provenance & Evidence