Trifluoroacetic acid → 2-{[4-(2-Hydroxyethyl)-1,3-thiazol-2-yl]thio}-2-methylpropionic acid ethyl ester

Participants

Reaction Steps

2-{[4-(2-Hydroxyethyl)-1,3-thiazol-2-yl]thio}-2-methylpropionic acid tert-butyl ester (8.4 g) obtained in Example 4 was dissolved in dichloromethane (50 mL), trifluoroacetic acid (50 mL) was added, and the mixture was stirred at room temperature for 12 hr. The reaction mixture was concentrated under reduced pressure, and the residue was dissolved in ethanol (100 mL). Thionyl chloride (8 mL) was added under ice-cooling, and the mixture was refluxed for 4 hr. Under ice-cooling, saturated aqueous sodium hydrogen carbonate solution was added to the reaction mixture, and the solvent was concentrated under reduced pressure. The mixture was extracted with ethyl acetate, and the organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel chromatography (elution solvent; hexane:ethyl acetate=1:1) to give the title compound (6.7 g) as a colorless oil.

Provenance & Evidence