反应详情

A mixture of 43 g (0.15 mol) of 2-amino-1-(2-guanidino-4-thiazolyl)ethanone dihydrochloride, 12.6 g (0.30 mol) of cyanamide, and 400 ml of water was brought to pH 4.5 by the dropwise addition of 20% sodium hydroxide solution. The mixture was heated at 50°-60° for 16 hours. The mixture was cooled, made basic with aqueous sodium carbonate solution and the resulting precipitate was collected by filtration, then washed successively with cold water, acetone, and ether. The dried solid was purified by dissolving in a minimum of dimethylformamide, then slowly adding ethyl acetate. Initially tarry material precipitated which was removed by decanting. Further addition of ethyl acetate afforded 16 g of a tan solid. This was again purified by the dimethylformamide-ethyl acetate procedure described above to give 12 g of a tan solid. Recrystallization of this material from methanol/water afforded analytically pure title compound as tan needles, mp 267° (dec). Calcd. for C7H9N7S: C, 37.66; H, 4.06; N, 43.91; S, 14.36; found: C, 37.81; H, 4.31; N, 43.76.

1. temperatureThe mixture was heated at 50°-60° for 16 hours
2. temperatureThe mixture was cooled
3. filtrationthe resulting precipitate was collected by filtration
4. washwashed successively with cold water, acetone, and ether
5. customThe dried solid was purified
6. dissolutionby dissolving in a minimum of dimethylformamide
7. customInitially tarry material precipitated which
8. customwas removed
9. customby decanting
10. additionFurther addition of ethyl acetate