反应详情

A mixture of 8.50 g (0.0625 mol) of 2-amino-1,4,5,6-tetrahydropyrimidine hydrochloride, 10.0 g (0.12 mol) of 50% NaOH and 70 ml of THF was stirred for 0.5 hours at room temperature and then 10.0 g Na2SO4 was added. After stirring for an additional 0.5 hours, a solution of 9.4 g (0.050 mol) of 2,6-dichlorophenyl isocyanate in 50 ml of THF was added over a period of 1 hour. After stirring for 1 hour, the reaction mixture was filtered, the filtrate evaporated in vacuo and the residue dissolved in 25 ml of 10% HCl and 25 ml of H2O with warming. After filtration through a pad of diatomaceous earth, chilling in ice gave the crystalline hydrochloride which was recrystallized from MeOH-ether affording 12.40 g. This material was ground to a fine powder and dried to constant weight in vacuo (60° C., 5 mm Hg) to give 11.97 g (74%) of the title compound; m.p. 215°-217° C. dec., homogeneous by TLC [5×20 cm silica gel GF CHCl3 --MeOH--NH4OH (90:9:1)]. 1H-NMR (DMSO-d6) 1.85 [pentet, (poorly resolved)2 H]; 3.35 (t, J=5 HZ, 4 H); 7.2-7.7 (m, 3 H); 9.16 (broad s, 2 H) exchangeable; 10.02 (broad s, 1 H) exchangeable; 11.19 (broad s, 1 H) exchangeable. IR(KBr) 3125, 1717, 1678, 1628 cm-1.; UV max. (MeOH) 241 infl. (ε=11,200) and 220 nm infl. (ε=23,500).

1. stirringAfter stirring for an additional 0.5 hours
2. stirringAfter stirring for 1 hour
3. filtrationthe reaction mixture was filtered
4. customthe filtrate evaporated in vacuo
5. dissolutionthe residue dissolved in 25 ml of 10% HCl
6. temperature25 ml of H2O with warming
7. filtrationAfter filtration through a pad of diatomaceous earth
8. temperaturechilling in ice