Dichloromethane → Ethyl 3-[(3-acetylthio-2-benzylbutanoyl)amino]benzoate

Participants

Reaction Steps

The compound prepared in the above (2) (5 g) and ethyl 3-aminobenzoate (4.3 g) are suspended in dichloromethane (25 ml), and thereto is added EDC.HCl (4.9 g). The mixture is stirred at room temperature for one hour. The reaction mixture is diluted with dichloromethane and washed with 10% hydrochloric acid, diluted aqueous sodium hydrogen carbonate solution and saturated aqueous sodium chloride solution in this order, dried over anhydrous sodium sulfate, and dichloromethane is distilled off under reduced pressure. The residue is dissolved in dichloromethane (25 ml) and thereto is added triethylamine (3.5 g) and further added dropwise methanesulfonyl chloride (3.9 g) with stirring under ice cooling, and the mixture is stirred at room temperature for one hour. The reaction mixture is diluted with dichloromethane and washed with 10% hydrochloric acid, diluted aqueous sodium hydrogen carbonate solution and saturated aqueous sodium chloride solution in this order, dried over anhydrous sodium sulfate, and dichloromethane is distilled off under reduced pressure. The residue is dissolved in ethanol (100 ml) and thereto is added potassium thioacetate (3.2 g), and the mixture is refluxed for 48 hours. Ethanol is distilled off under reduced pressure, and the residue is extracted with ethyl acetate. The extract is washed with 10% hydrochloric acid, diluted aqueous sodium hydrogen carbonate solution and saturated aqueous sodium chloride solution in this order, and ethyl acetate is distilled off under reduced pressure. The residue is dissolved in acetonitrile and purified by a medium pressure column chromatography with CHP-20P (eluant, water-acetonitrile). The fractions containing the desired compound are collected and concentrated into dryness under reduced pressure to give ethyl 3-[(3-acetylthio-2-benzylbutanoyl)amino]benzoate (1.4 g). IR (film; cm -1): 1720, 1690, 1660

Provenance & Evidence