To 2-dimethylaminomethyl-6-methylaminopyridine (2.14 g, 0.013 mol) in dry benzene (35 ml) is added triethylamine (1.77 g, 0.0175 mol) and dimethylcarbamoyl chloride (1.72 g, 0.016 mol). The solution is stirred under nitrogen at reflux for 16 hours overnight. The mixture is cooled to room temperature and filtered. The filtrate is concentrated in vacuo and the residual oil is taken up in ether, filtered and again concentrated in vacuo. The residual oil is converted to the monohydrochloride salt with 6N ethanolic hydrochloric acid (1.7 ml, 0.0103 mol). The solid is recrystallized from ethanol-ether several times, affording 2.2 g of N,N,N'-trimethyl-N'-(6-dimethylaminomethyl-2-pyridyl)urea hydrochloride hemihydrate as a white solid, m.p. 154°-155° C.
