Sodium Hydroxide → N-(2,6-Dimethylphenyl)-N'-(1,4,5,6-tetrahydropyrimidin-2-yl)urea Monohydrochloride Hydrate

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Reaction Steps

A mixture of 8.13 g (0.060 mol) of 2-amino-1,4,5,6-tetrahydropyrimidine hydrochloride, 5.0 g (0.0625 mol) of 50% NaOH and 75 ml of THF was stirred for 0.5 hours at room temperature and then 10.0 g Na2SO4 was added. After stirring for 0.5 hours, a solution of 5.89 g (0.040 mol) of 2,6-dimethylphenyl isocyanate in 50 ml of THF was added over a period of 0.5 hours. After stirring for 1 hour, the reaction mixture was diluted with 100 ml of CH2Cl2, filtered, the filtrate evaporated in vacuo and the residue dissolved in 25 ml of 10% HCl and 50 ml of H2O with warming. After filtration through a pad of diatomaceous earth, chilling in ice gave the crystalline hydrochloride which was recrystallized from cold H2O affording 8.78 g (55%). This material was dried in vacuo (20° C., 5 mm Hg) to constant weight giving N-(2,6-dimethylphenyl)-N'-(1,4,5,6-tetrahydropyrimidin-2-yl)urea monohydrochloride hydrate (10:10:11); m.p. (110) 214.5°- 216.5° C. dec.; IR (CHCl3) 3226, 1710, 1676, 1641 cm-1. UV max. (MeOH) 270 shl (ε1,000) and 233 nm (ε18,300).

Provenance & Evidence