Chloride → 2-(6-Methoxynaphthalen-2-yl)propanoyl chloride

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Reaction Steps

2.85 ml, 32.5 mmol Oxaly chloride ((COCl)2) is added slowly to 3 g, 13 mmol (S)-2-(6-methoxy-2-naphthyl)propionic acid dissolved in 3 ml dichloromethane (CH2Cl2), and the resulting solution is heated under a first reflux temperature with stirring for 2 hours. The excess oxaly chloride is removed by evaporation under reduced pressure to obtain a crude product of (S)-2-(6-methoxy-2-naphthyl)propionic acid chloride. The crude (S)-2-(6-methoxy-2-naphthyl)propionic acid chloride is dissolved in 5 ml dichloromethane and then added to a solution of 3.36 ml, 32.5 mmol N,N′-diethylamine (HN(CH2CH3)2) and 5 ml triethylamine (TEA) in 10 ml dichloromethane with stirring under ice bath, i.e. under a temperature about 0° C. After some solids are produced, the mixture is stayed in a refrigerator overnight, i.e. stayed in a low temperature about−5° C. for a period of time about 12 hour. The mixture is evaporated to dryness under reduced pressure and the residue is purified by column chromatography over silica gel (70˜230 mesh ASTM) using dichloromethane/ethyl acetate (V:V=8:2) as the eluant. As a result, about 70 percent yield of white N,N′-diethyl (S)-2-(6-methoxy-2-naphthyl)propionate is obtained, which is the first intermediate (I) for synthesizing the chiral compound of the first preferred embodiment of the present invention.

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