Hydrochloric Acid → Benzene, 1-cyclopenten-1-yl-

Participants

Reaction Steps

To a solution of 3.0 M solution of phenylmagnesium bromide in ether (49.7 mL, 149 mmol) was added THF (300 mL). To this solution cooled to 0° C. cyclopentanone (13.23 mL, 149 mmol) was added. The reaction mixture was stirred at room temperature for 30 min, then at reflux for 2 h. Ice (20 g) was added, followed by 6 N HCl, until the precipitate dissolved. The product was extracted with ether. The combined etherial layers were washed with saturated sodium bicarbonate solution, dried over anhydrous magnesium sulfate and filtered. The solvent was removed in vacuo and the residue was purified by column chromatography on silica gel to give cyclopentenylbenzene (21.49 g, 149 mmol, 100% yield) as a colorless oil. LC-MS (M+H)+=145.1. 1H NMR (500 MHz, chloroform-d) δ ppm 7.48 (2H, d, J=7.3 Hz), 7.35 (2H, t, J=7.8 Hz), 7.22-7.27 (1H, m), 6.22 (1H, t, J=2.1 Hz), 2.70-2.80 (2H, m), 2.52-2.64 (2H, m), 2.01-2.12 (2H, m).

Provenance & Evidence