Citric Acid → N-[7-(2-chloro-4,6-dimethylphenyl)-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridin-3-yl]propionamide

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Reaction Conditions

Reaction Steps

To a stirred solution of 7-(2-chloro-4,6-dimethylphenyl)-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridin-3-ylamine (5-45; 0.51 g) and triethylamine (0.27 mL) in dichloromethane (40 mL) cooled to 0° C. was added dropwise over 25 minutes a solution of propionyl chloride (0.17 mL) in dichloromethane (10 mL). The resulting mixture was stirred for an additional 1 h at 0° C., followed by 14 h at room temperature. The reaction mixture was stirred with an aqueous 5% citric acid solution (40 mL) for 10 minutes. The layers were separated, and the aqueous layer was further extracted with dichloromethane (50 mL). The combined organic extracts were dried over anhydrous sodium sulfate, decanted from the desiccating agent and concentrated in vacuo. The resulting residue was purified by silica gel chromatography using a dichloromethane/methanol gradient to afford N-[7-(2-chloro-4,6-dimethylphenyl)-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridin-3-yl]propionamide (7-6; 0.49 g) as an off white solid: ms (MH+)=347.

Provenance & Evidence