4-Methoxyphenyl isothiocyanate → 1-(2,2-Dimethoxyethyl)-3-(4-methoxyphenyl)thiourea

Participants

Reaction Steps

A solution of 10 g (0.06 mole) of p-methoxyphenyl isothiocyanate in 100 ml of chloroform was treated with 6.3 g (0.06 mole) of aminoacetaldehyde dimethyl acetal. The solvent was evaporated and the residue was recrystallized from ethanol to yield N-(p-methoxyphenyl)-N'-(β,β-dimethoxyethyl)thiourea, 9.2 g (57%). A suspension of this thiourea in a solution of 5 ml of concentrated sulfuric acid and 20 ml of water was refluxed for 3 hours. The mixture was cooled and a solid was filtered, washed with water, and dried. Recrystallization from ethanol gave 1-(4-methoxyphenyl)-2-mercaptoimidazole, 4.9 g (70%), mp 215°-217° C.

Provenance & Evidence