Hydrochloric Acid → 3-Methylthio-p-phenylenediamine hydrochloride

Participants

Reaction Steps

In a Paar hydrogenation bottle, a mixture of 3-methylthio-4-nitroaniline (7.7 g), 5% Pd/C catalyst (8.0 g), concentrated hydrochloric acid (7 ml) and ethanol (200 ml) is treated with hydrogen at 3.43 kg/cm2 for 45 minutes (until 0.8 kg/cm2Hydrogen is absorbed). The mixture is filtered through diatomaceous earth and the filtrate evaporated to dryness afford 3-methylthio-p-phenylenediamine hydrochloride. The salt is dissolved in water, the solution made alkaline (pH 9-10) with 50% sodium hydroxide and the diamine extracted with methylene chloride (3×150 ml). The combined extracts are dried over magnesium sulfate and evaporated to dryness to afford 4.75 g of title product, a brown solid, which is used as is.

Provenance & Evidence