3-(Phenylthio)propanoic acid → Thiochroman-4-one

Participants

Reaction Conditions

Reaction Steps

Polyphosphoric acid (110 g) was admixed with 3-phenylsulfanylpropionic acid (13.54 g, 74 mmol) and the reaction mixture was stirred at 60° C. for 96 h. After cooling to RT, the reaction mixture was admixed with water (250 ml) and extracted with diethyl ether (3×100 ml). The combined organic phases were washed with 5% eq. NaHCO3 solution (50 ml), washed with water (50 ml) and dried over sodium sulfate, and the solvent was removed under reduced pressure. After column chromatography purification of the residue (silica gel, 8:1 cyclohexane/MTBE), the desired product was obtained as a greenish oil (8.0 g, 66% of theory).

Provenance & Evidence