N-Methylaniline → 4-Chloro-N,3-dimethyl-N-phenyl-1-(2-pyridinyl)-1H-pyrazolo[3,4-b]pyridine-5-carboxamide

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Reaction Conditions

Reaction Steps

A solution of 4-hydroxy-3-methyl-1-(2-pyridinyl)-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid (2.0 g, 7.4 mmol) in phosphorous oxychloride (15 mL, 63 mmol) was heated and stirred at 100° C. for 3 hours. After the solution was cooled to room temperature, the solvent was evaporated under reduced pressure. The residue was dissolved in tetrahydrofuran (50 mL). To the solution, a solution of N-methylaniline (1.0 mL, 9.2 mmol) and triethylamine (5.2 mL, 37 mmol) in tetrahydrofuran (10 mL) was added at 0° C. After the mixture was stirred at room temperature for 1.5 hours, the reaction solvent was evaporated under reduced pressure. Purification of the residue thus obtained by silica gel chromatography (chloroform:methanol=50:1 to 20:1) gave the title compound (2.14 g, 76% yield).

Provenance & Evidence