Ethyl acetate hexane → HCID 86673454, compound

Participants

Reaction Steps

To (S)-tert-butyl 2-oxo-1-(3-(phenylethynyl)phenyl)ethylcarbamate (95 mg, 0.283 mmol) in tetrahydrofuran (5 mL) at −78° C. was added phenylmagnesium bromide (0.198 mL, 0.595 mmol) dropwise. After half of the phenylmagnesium bromide was added the stir bar stopped spinning due to a gum which formed around it. The ice bath was removed allowing the reaction to warm until the stir bar began to stir again. The addition of Grignard reagent was continued and after 1 h, a fine precipitate was evident. TLC (25% ethyl acetate/hexane; UV and phosphomolybdic acid) showed a single major spot just below starting material (Rf=0.45). After 1.5 h total, the reaction was quenched with 1N HCl (10 mL) and extracted into ethyl acetate (3×10 mL). The combined organics were washed with saturated NaHCO3, brine, dried over MgSO4, filtered and concentrated in vacuo to 126 mg amber oil which was loaded with dichloromethane onto a 12 g silica gel column prepacked with 5% ethyl acetate/hexanes. Elution with 5 to 30% ethyl acetate/hexanes over 250 mL provided 62 mg tert-butyl (1S,2S)-2-hydroxy-2-phenyl-1-(3-(phenylethynyl)phenyl)ethylcarbamate as a colorless oil which was used directly in the next step.

Provenance & Evidence