Hydrochloric Acid → 2,2-diphenylpent-4-enoic acid

Participants

Reaction Steps

A solution of diphenylacetic acid (250 g., 1.17 mol ) in 2.4 L of tetrahydrofuran was stirred at 0° C. under argon while 0.94 L of a 2.5M solution on n-butyllithium in hexane was added dropwise. After 1 hour, allyl bromide (142.5 g, 1.17 mole) was added in one portion. After 15 minutes, 500 mL of 10% hydrochloric acid was added, along with ether (2 L). The layers were separated, the aqueous layer extracted with ethyl ether (1×250 mL), the organic layers combined, washed with brine, dried (MgSO4), and filtered. Concentration afforded 296 g (99%) of an off-white solid, mp 134°-137° C. 1H NMR (CDCl3)δ 7.3 (m, 10H), 5.6 (m, 1H), 4.9 (bs, 2H), 3.2 (d, 2H).

Provenance & Evidence