Boron trifluoride etherate → HCID 178505387, compound

Participants

Reaction Conditions

Reaction Steps

3-(2,2-Difluoro-1,3-benzodioxol-4-yl)-4-nitropyrazole obtained above in Example 17 is reduced to 4-amino-3-(2,2-difluoro-1,3-benzodioxol-4yl)pyrazole according to the method described by Vogel (Practical Organic Chemistry, Fourth Edition p. 660: Fe/HCl). 0.8 g (0.003 mol) of 4-amino-3-(2,2-difluoro-1,3-benzodioxol-4-yl)pyrazole in solution in 10 ml of anhydrous THF is treated at 0° C. with a solution of 10 ml of THF-containing 1 ml (0.0081 mol) of boron trifluoride etherate. 0.6 ml (0.005 mol) of tert-butyl nitrite in solution in 5 ml of THF are then added to the reaction mixture. Stirring is maintained for 1 hour at 0° C., the reaction mixture is then diluted with pentane and filtered on a sintered glass. After drying, a beige powder is obtained.

Provenance & Evidence