Triethylamine → (S)-3-(Thiophen-2-ylthio)butanoic acid

Participants

Reaction Steps

To a magnetically-stirred 25 mL round-bottomed flask blanketed with nitrogen was charged 2-mercaptothiophene (0.73 g, 6.29 mmol) in tetrahydrofuran (7 mL, K.F. <0.1 mg/mL) at 25° C. Triethylamine (0.87 mL, 6.29 mmol) was injected and the reaction mixture was stirred for 10 minutes to complete salt formation. To this mixture was added (R)-(+)-β-methyl-β-propiolactone (0.54 g, 6.29 mmol) in one portion and the reaction mixture was stirred at 25° C. for approximately 3 hours. When complete, the mixture was stripped of solvent on a rotary evaporator at 25° C. and diluted with ethyl acetate (10 mL) and water (10 mL). The pH of the mixture was then adjusted to 2.0 with 5N hydrochloric acid and the layers separated. The upper ethyl acetate product layer was dried over sodium sulfate and concentrated to an oil on a rotary evaporator. Silica gel chromatography (10% ethyl acetate/hexanes) afforded 1.19 g of (S)-3-(2-thienylthio)butyric acid (94%).

Provenance & Evidence