Reacción #833094

Ecuación de reacción

nitric acid

2,3,5-trichlorobenzoyl cyanide

aminoguanidine bicarbonate

→

3,5-diamino-6-(2,3,5-trichlorophenyl)-1,2,4 -triazine

Disolventes

dimethylsulphoxide

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.WAITwas left
2. 2
   workup.WAITto stand at room temperature for 21 days
3. 3
   FiltraciónThe solid was filtered off
4. 4
   Lavadowashed with water (2×100 ml)
5. 5
   Otrodried in vacuo
6. 6
   workup.ADDITIONA suspension of the dried solid in a 10% solution of potassium hydroxide pellets in methanol (320 ml)
7. 7
   Temperaturawas heated
8. 8
   Temperaturato reflux for 1 hour
9. 9
   Temperaturathe mixture was cooled
10. 10
    Otroevaporated down in vacuo
11. 11
    workup.ADDITIONThe residue was treated with ice/water (200 ml)
12. 12
    Filtraciónthe resultant solid was filtered off
13. 13
    Otrodried in vacuo
14. 14
    Lavadoeluted with a solution of ethyl acetate/methanol/acetic acid (90:2.5:2.5)
15. 15
    OtroFractions 50 to 80 (900 drops per fraction) were collected
16. 16
    Otroevaporated down in vacuo
17. 17
    OtroThe resultant solid was recrystallised from ispropanol

Procedimiento

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).

Fuente