Hydrochloric Acid → 2-(2,2-Diphenylethylamino)-1,4,5,6-tetrahydropyrimidine hydrochloride

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Reaction Conditions

Reaction Steps

A flask containing a mixture of 2,2-diphenylethylamine (5.92 g; 3.00×10-2 mole) and 2-methylthio-1,4,5,6-tetrahydropyrimidine hydroiodide (7.74 g, 3.00×10-2 mole) was immersed in an oil bath which had been preheated to ca. 155° C. The reaction was stirred at between 150°-168° C. for 1.5 hours. The resulting yellow glass was dissolved in methanol. The methanol was evaporated and the resulting yellow oil was dissolved in dichloromethane. This solution was transferred to a separatory funnel where it was washed with 2N aqueous NaOH and saturated aqueous NaCl. After drying over anhydrous Na2SO4, the dichloromethane was evaporated giving a foam which was dissolved in methanol (125 ml). This solution was cooled to 0° C. at which time it was treated with a methanolic solution of HCl. After 10-15 minutes most of the methanol was evaporated and 2-butanone was added. After several days the crystals were collected by filtration. Recrystallization from isopropanol afforded 2-(2,2-diphenylethylamino)-1,4,5,6-tetrahydropyrimidine hydrochloride as off-white crystals: 3.80 g (40%), m.p. 180°-182° C.

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