1-Indanone, 6-bromo- → 6-Bromo-1-methylene-indan

Participants

Reaction Steps

A 2.5 M solution of n-BuLi in hexanes (23.6 mL, 59 mmol) was added dropwise to a 0° C. slurry of methyltriphenylphosphonium bromide (16.8 g, 47.0 mmol) in THF (200 mL). After 1 h, a solution of 6-bromo-2,3-dihydro-1H-inden-1-one (10.0 g, 47.0 mmol) in THF (50 mL) was added to the resulting solution and the reaction cold bath was removed. Upon completion, the reaction was quenched with water (40 mL). The layers were separated and the aqueous layer was extracted with EtOAc (2×40 mL). The combined organics were washed with brine (50 mL), dried over Na2SO4, filtered and concentrated to afford 6-bromo-1-methylene-2,3-dihydro-1H-indene (6.06 g, 62% yield) as a clear oil after purification by flash chromatography over silica gel (hexane eluent). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 7.61 (d, J=1.5 Hz, 1H), 7.32 (dd, J=8.0, 1.8 Hz, 1H), 7.13 (d, J=8.0 Hz, 1H), 5.45 (t, J=2.5 Hz, 1H), 5.08 (t, J=2.1 Hz, 1H), 2.88-2.98 (m, 2H), 2.78-2.86 (m, 2H); MS (EI) m/z=210.1 [M+1]+.

Provenance & Evidence