Bromomethylcyclopropane → 1-(3-Bromophenyl)pent-4-en-1-one

Participants

Reaction Steps

A mixture of magnesium (0.48 g, 20.29 mmol) in THF was treated dropwise with (bromomethyl)cyclopropane (2.49 g, 18.45 mmol) in THF, heated at reflux temperature for 1 hour, poured into a cold (0° C.) mixture of 3-bromo-N-methoxy-N-methylbenzamide (2.5 g, 10.24 mmol) and THF, allowed to come to room temperature, stirred for 10 min, quenched with aqueous NH4Cl and extracted with ethyl ether. The organic extracts were combined, dried over MgSO4 and concentrated in vacuo. Purification of the resultant residue on silica gel (ISCO) using hexanes/EtOAc 10/1 as the eluting solvents gave a clear oil (2.4 g, 54% yield), MS m/e (M−H)+ 239; 1H NMR (400 MHz, DMSO-d6) 2.3 (m, 2H), 3.1 (t, J=7.19 Hz, 2H), 5.02 (m, 2H), 5.8 (m, 1H), 7.47 (t, J=7.93 Hz, 2H), 7.77 (dd, J=7.08, 2.2 Hz), 7.94 (dd, J=7.81, 1.58 Hz), 8.04 (t, J=1.83 Hz, 1H).

Provenance & Evidence