反应详情

To a solution of 5-methyl-1-[5-(trifluoromethyl)pyridin-2-yl]-1H-pyrazole-4-carboxylic acid (2.07 g) described in Reference Example 8 in dichloromethane (50 ml) were added oxalyl chloride (2.62 ml) and N,N-dimethylformamide (catalytic amount) at room temperature, stirred at room temperature for 2 hours, and then the solvent and an excess amount of oxalyl chloride were evaporated. To the obtained reaction mixture was added tetrahydrofuran (50 ml), then 28% ammonia aqueous solution (30 ml) was added thereto under ice-cooling, and stirred at room temperature overnight. After completion of the reaction, the organic solvent was evaporated in vacuo, then 1 N aqueous solution of sodium hydroxide was added thereto, the precipitated solid was collected by filtration, and dried at 60° C. under air blow to give the titled compound (1.8 g) as a pale yellow solid. MS (ESI) m/z: 271 (M+H)+.

1. customthe solvent and an excess amount of oxalyl chloride were evaporated
2. customTo the obtained reaction mixture
3. temperatureunder ice-cooling
4. stirringstirred at room temperature overnight
5. customAfter completion of the reaction
6. customthe organic solvent was evaporated in vacuo
7. addition1 N aqueous solution of sodium hydroxide was added
8. filtrationthe precipitated solid was collected by filtration
9. customdried at 60° C. under air blow