Triethylamine → (s)-Methyl 2-oxooxazolidine-4-carboxylate

Participants

Reaction Steps

A solution of L-serine methyl ester hydrochloride (3.063 kg) in dichloromethane (24.1 L) at 0° C. was treated with triethylamine (5.908 kg), stirred for 30 minutes, treated with triphosgene (1.949 kg) in dichloromethane (5.356 kg) over 6.5 hours, stirred for 45 minutes, treated with hexanes (12.23 kg), stirred for 55 minutes, and filtered with ethyl acetate (16.013 kg). The filtrate was concentrated to provide a 35% (w/w) solution of the desired product (93.5%, 98% ee) in ethyl acetate. 1H NMR (300 MHz, CDCl3) δ6.55 (br s, 1H), 4.62 (dd, J=9, 9 Hz, 1H), 4.53 (dd, J=4, 9 Hz, 1H), 4.45 (dd, J=4, 9 Hz, 1H), 3.83 (s, 3H).

Provenance & Evidence