Potassium Carbonate → 7-Methoxy-3-(4-methoxyphenyl)thiochroman-4-one

Participants

Reaction Conditions

Reaction Steps

To acetonitrile solution (120 ml) of 2-(4-methoxyphenyl)-3-(3-methoxyphenylthio)propionic acid (4) (12.8 g, 40.3 mmol) obtained above was added potassium carbonate (1.59 g, 11.5 mmol) and phosphorus oxychloride (18.7 ml, 200 mmol) at 0° C. and then stirred for 18 hours at 60° C. The reaction solution was quenched with ice-water and extracted with ether. The organic layer was washed with saturated saline, dried over anhydrous magnesium sulfate and then distilled under reduced pressure to remove the solvent. The obtained crude product was washed with ether to obtain 6.8 g of the first crop of 7-methoxy-3-(4-methoxyphenyl)thiochroman-4-one (5). Further, the filtrate was concentrated and the residue was then purified with silica gel column chromatography (ethyl acetate:hexane=1:3) to obtain 1.0 g of the second crop of 7-methoxy-3-(4-methoxyphenyl)thiochroman-4-one (5) (total yield: 7.8 g, 65%). NMR data of the compound (5) was identical to that described in Example 25.

Provenance & Evidence