反应详情

A solution of 2,3,5-trichlorobenzoyl cyanide (38.5 g, 0.16M) in dimethylsulphoxide (80 ml) was added dropwise to a stirred suspension of aminoguanidine bicarbonate (65.76 g, 0.32M) which had been treated with 8N aqueous nitric acid (560 ml). The mixture was stirred for 3 hours and then was left to stand at room temperature for 21 days. The solid was filtered off, washed with water (2×100 ml) and dried in vacuo. A suspension of the dried solid in a 10% solution of potassium hydroxide pellets in methanol (320 ml) was heated to reflux for 1 hour, the mixture was cooled and evaporated down in vacuo. The residue was treated with ice/water (200 ml), the resultant solid was filtered off and dried in vacuo. This dried solid was put on top of a dry column (25 mm diameter, 200 g of MFC silica gel) and eluted with a solution of ethyl acetate/methanol/acetic acid (90:2.5:2.5). Fractions 50 to 80 (900 drops per fraction) were collected, combined and evaporated down in vacuo. The resultant solid was recrystallised from ispropanol to give 3,5-diamino-6-(2,3,5-trichlorophenyl)-1,2,4 -triazine. Yield 0.77 g (1.6%), m.p. 232°-235° C. (uncorrected).

1. waitwas left
2. waitto stand at room temperature for 21 days
3. filtrationThe solid was filtered off
4. washwashed with water (2×100 ml)
5. customdried in vacuo
6. additionA suspension of the dried solid in a 10% solution of potassium hydroxide pellets in methanol (320 ml)
7. temperaturewas heated
8. temperatureto reflux for 1 hour
9. temperaturethe mixture was cooled
10. customevaporated down in vacuo
11. additionThe residue was treated with ice/water (200 ml)
12. filtrationthe resultant solid was filtered off
13. customdried in vacuo
14. washeluted with a solution of ethyl acetate/methanol/acetic acid (90:2.5:2.5)
15. customFractions 50 to 80 (900 drops per fraction) were collected
16. customevaporated down in vacuo
17. customThe resultant solid was recrystallised from ispropanol