N-methyl-2-pyrrolidone → (4S)-3-{(2S)-2-[(S)-[3,5-bis(trifluoromethyl)phenyl](hydroxy)methyl]but-3-enoyl}-4-phenyl-1,3-oxazolidin-2-one

Participants

Reaction Conditions

Reaction Steps

To (4S)-3-[(2E)-but-2-enoyl]-4-phenyl-1,3-oxazolidin-2-one (13.8 g, 59.7 mmol) in DCM (100 mL) was added TiCl4 (1M in DCM, 59.7 mL, 59.7 mmol) at −10° C. The resulting reaction solution was transferred by cannula to a flask containing DIPEA (11.26 mL, 64.5 mmol) and DCM (100 mL) at 10° C. NMP (11.49 mL, 119 mmol) was added via a syringe and the reaction mixture was aged for 1 hour before cooling to −40° C. 3,5-Bis(trifluoromethyl)benzaldehyde (17.3 g, 71.6 mmol) in DCM (25 mL) was added via a syringe and the reaction was allowed to warm to 0° C. over 1.5 hr. The reaction was quenched by addition of acetic acid (15 mL), saturated Rochelle's salt (50 mL) and HCl (1.0 M, 200 mL). The organic was separated and the aqueous was back extracted with DCM (50 mL). The organics were combined, washed with HCl (1.0 M, 100 mL), dried over sodium sulfate, filtered and concentrated. The resultant oil was purified by column chromatography to give (4S)-3-{(2S)-2-[(S)-[3,5-bis(trifluoromethyl)phenyl](hydroxy)methyl]but-3-enoyl}-4-phenyl-1,3-oxazolidin-2-one (20 g, 42.3 mmol) as crystalline solid. 1H NMR (500 MHz, CDCl3) δ7.86 (s, 2H), 7.83 (s, 1H), 7.4 (m, 5H), 5.7 (m, 1H), 5.4 (m, 1H), 5.31 (d, J=10.3 Hz, 1H), 5.28 (d, J=3.9 Hz, 1H), 5.10 (d, J=17.3 Hz, 1H), 4.8 (m, 1H), 4.7 (t, J=9.0 Hz, 1H), 4.3 (m, 1H).

Provenance & Evidence