Reaction #51143

Reaction equation

water

ethanol

sodium borohydride

1-(2,6-dichloro-4-trifluoromethylphenyl)-5-(pyrazin-2-ylchloromethylimino)pyrazole-3-carbonitrile

→

1-(2,6-dichloro-4-trifluoromethylphenyl)-5-(pyrazin-2-ylmethylamino)pyrazole-3-carbonitrile

Yield 92.4%

Solvents

ethyl acetate

Conditions

Workup

1. 1
   Otherat 20° C. or less
2. 2
   Otherto precipitate crystals
3. 3
   workup.STIRRINGAfter 30 minutes of stirring
4. 4
   Filtrationthe crystals were filtrated
5. 5
   Washwashed with water until the pH of the filtrate
6. 6
   OtherThe crystals thus obtained
7. 7
   Extractionthe solution was extracted
8. 8
   workup.ADDITIONafter the addition of saturated saline
9. 9
   DryingThe organic layer was dried over anhydrous magnesium sulfate
10. 10
    Filtrationfiltrated
11. 11
    Concentrationconcentrated
12. 12
    FiltrationThe resulting crystals were filtrated
13. 13
    Washwashed with a small amount of hexane and ethyl acetate
14. 14
    Otherdried

Procedure

To an ethanol (2 ml) suspension of 85 mg (2.2 mmol) of sodium borohydride was gradually added 0.5 g (1.1 mmol) of 1-(2,6-dichloro-4-trifluoromethylphenyl)-5-(pyrazin-2-ylchloromethylimino)pyrazole-3-carbonitrile at 20° C. or less. After 1 hour of stirring at room temperature, the mixture was gradually poured into 40 ml of water to precipitate crystals. After 30 minutes of stirring, the crystals were filtrated and washed with water until the pH of the filtrate became 6. The crystals thus obtained were dissolved in ethyl acetate and the solution was extracted after the addition of saturated saline. The organic layer was dried over anhydrous magnesium sulfate, filtrated, and concentrated. The resulting crystals were filtrated, washed with a small amount of hexane and ethyl acetate, and dried to obtain 0.42 g (yield 92%) of 1-(2,6-dichloro-4-trifluoromethylphenyl)-5-(pyrazin-2-ylmethylamino)pyrazole-3-carbonitrile.

Source