Hydrochloric Acid → 4-Methoxy-3-methylsulfanylbenzoic acid

Participants

Reaction Steps

Triphenylphosphine (20.5 g; 78.2 mmol) was introduced a little at a time into a solution of 5c (5.1 g; 18.3 mmol) in toluene (50 ml). The reaction mixture was stirred at room temperature for 4.5 h. The precipitate (triphenylphosphine oxide) was filtered off, and the yellow filtrate was extracted with 10% strength aqueous sodium hydroxide solution (4×). Dimethyl sulfate (2 ml) was added to the combined aqueous extract, and the reaction mixture was stirred at room temperature for 2 h. The precipitate obtained was dissolved by heating to reflux temperature. The clear solution was cooled and adjusted to pH 1 using 20% strength hydrochloric acid. The precipitate (7c) was filtered off, washed with H2O and dried under reduced pressure over CaCl2.

Provenance & Evidence