1,2-Ethanediamine, 4-methylbenzenesulfonate (1:?) → p-Toluenesulfonic acid

Participants

Reaction Steps

A mixture of 27 g of 4-methylthiophenoxyacetonitrile and 35 g of ethylenediamine p-toluenesulfonate in 50 ml of 1,2-dichlorobenzene was heated at 158°-180° C. for about 45 minutes. The reaction mixture was cooled, diluted with CH2Cl2 and filtered to obtain the p-toluenesulfonate salt. After washing with CH2Cl2, the p-toluenesulfonate salt was slurried with water and then 40 ml of an aqueous 5 normal (N) sodium hydroxide solution added to the slurry. Extracting the mixture with CH2Cl2 and then evaporating the CH2Cl2 left 30 g of the free base. The free base was heated in cyclohexane/methylchloroform, the resulting mixture was then cooled and the solids removed by filtration. The free base was then dissolved in 150 ml of isopropanol and acidified with hydrochloric acid (HCl) in isopropanol to give the hydrochloride salt (31 g). The 2-((4-(methylthio)phenoxy)methyl)-2-imidazoline hydrochloride was found to have a m.p. of 190°-191° C.

Provenance & Evidence