Benzenepropanoyl chloride → HCID 13461746, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of (R)-(+)-4-benzyl-2-oxazolidinone (910 g, 5.14 mol) and 500 mg of 2,2′-dipyridyl as an indicator in tetrahydrofuran (9 L) at −78° C. was added over 30 minutes a 2.5 M solution of BuLi in hexanes (2.03 L, 5.14 mol). The temperature of the reaction mixture was maintained at less than −55° C. during the addition. The reaction mixture was cooled to −75° C. and hydrocinnamoyl chloride (950 g, 5.63 mol) was added over 5 minutes. The reaction mixture was allowed to warm to 0° C., at which point the reaction mixture was judged to be complete by thin layer chromatography (hexanes/ethyl acetate, 2:1). The reaction was quenched by adding 10% aqueous sodium bicarbonate (3.6 L) and water (3.6 L). The aqueous phase was separated and extracted with ethyl acetate (3 L). The combined organic layers were washed with 5% aqueous sodium carbonate (3.6 L) and saturated aqueous sodium chloride (2 L), dried over magnesium sulfate, and concentrated in vacuo to approximately 2 L of a viscous yellow suspension. This slurry was dissolved in ethyl acetate (3 L), concentrated to a solid, and dissolved in ethyl acetate at 50° C. Hexanes (10.7 L) was added, and the mixture was slowly cooled to 10° C. resulting in the precipitation of solids which were stirred at 10° C. for 30 minutes. The solids were collected by filtration, washed with hexanes, and air-dried at ambient temperature yielding 1.4 kg (88%) of (R)-4-benzyl-3-(3-phenyl-propionyl)-oxazolidin-2-one as pale yellow needles: 1H NMR (300 MHz, CDCl3) δ7.14-7.33 (m, 10H), 4.66 (m, 1H), 4.17 (t, J=3.4 Hz, 2H), 3.26 (m, 3H), 3.03 (t, J=7 Hz, 2H), 2.75 (dd, J=9.5, 13.4 Hz, 1H); IR 1787, 1761, 1699, 1390, 1375, 1308, 1208, 1203, 746, 699 cm−1; mp 102-104° C.

Provenance & Evidence