反应详情

A solution of 4(5)-[(2-aminoethyl)thiomethyl]imidazole (6.0 g.) and benzoyl isothiocyanate (6.0 g.) in chloroform (150 ml.) was heated under reflux for one hour. Concentration followed by recrystallisation from ethyl acetate-isopropyl acetate afforded N-benzoyl-N'-[2-(4-imidazolylmehylthio)-ethyl]thiourea (7.5 g.). An analytically pure sample (from aqueous isopropyl alcohol) had m.p. 126°-128°. (ii) The benzoyl thiourea (6.0 g.) was added to a solution of potassium carbonate (1.4 g.) in water (80 ml.), at 60°. The solution was maintained at this temperature for one hour, concentrated to low bulk and acidified with hydrochloric acid. Benzoic acid was removed by filtration and the filtrate was basified with potassium carbonate and concentrated under reduced pressure. Following extraction with isopropyl alcohl and concentration, the product was crystallised from isopropyl acetate. Recrystallisation from water gave N-[2-(4-imidazolylmethylthio)ethyl]thiourea (2.5 g.) m.p. 135°-137°. (Found: C, 38.9; H, 5.5; N, 26.1; S, 29.6. C7H12N4S2 requires: C, 38.9; H, 5.6; N; 25.9; S, 29.6).

1. temperatureThe solution was maintained at this temperature for one hour
2. concentrationconcentrated to low bulk
3. customBenzoic acid was removed by filtration
4. concentrationconcentrated under reduced pressure
5. extractionextraction
6. concentrationwith isopropyl alcohl and concentration
7. customthe product was crystallised from isopropyl acetate
8. customRecrystallisation from water