Dimethylformamide → 5-methyl-1-[4-(trifluoromethyl)phenyl]-1H-pyrazole-4-carboxamide

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Reaction Steps

Oxalyl chloride (3.8 ml) and N,N-dimethylformamide (catalytic amounts) were added at room temperature to a solution of 5-methyl-1-[4-(trifluoromethyl)phenyl]-1H-pyrazole-4-carboxylic acid (3.0 g) described in Reference Example 23 in dichloromethane (50 ml) and stirred at room temperature for two hours. The solvent and an excess amount of oxalyl chloride were evaporated, tetrahydrofuran (50 ml) was added to the residue, 28% aqueous ammonia was added under ice-cooling, and stirred at room temperature for two hours. After the reaction, the reaction solution was diluted with water and extracted with ethyl acetate. The resulting organic layer was washed with 1N hydrochloric acid aqueous solution, 4N aqueous solution of sodium hydroxide, water and saturated brine successively, dried over anhydrous sodium sulfate and concentrated to give 5-methyl-1-[4-(trifluoromethyl)phenyl]-1H-pyrazole-4-carboxamide (2.92 g) as a pale brown solid.

Provenance & Evidence