Hydrochloric Acid → N-Cyclopropylmethyl-N-(2-ethylpyrazolo[1,5-a]pyridin-3-yl)-N-tetrahydro-2H-4-pyranylmethylamine

Participants

Reaction Steps

A solution of N4-cyclopropylmethyl-N4-(2-ethylpyrazolo[1,5-a]pyridin-3-yl)tetrahydro-2H-4-pyrancarboxamide (220 g, 672 mmol) in tetrahydrofuran (1100 mL) was stirred at an external temperature of 55° C. (hot water bath). A borane-tetrahydrofuran complex (1M solution, 1748 mL) was added dropwise to the reaction mixture, and after heating and stirring for 2 hours, the reaction mixture was cooled in an ice bath and 2N hydrochloric acid (437 mL) was added. The reaction mixture was then stirred for 1 hour at an external temperature of 50° C. (hot water bath). After the reaction terminated, a 5N aqueous sodium hydroxide solution (299 mL) was added dropwise to the reaction mixture to adjust it to pH 8, and the aqueous layer was removed. Toluene (2200 mL) was then added to the organic extract, and after washing the organic extract twice with water, it was concentrated under reduced pressure to afford 209 g of the title compound (99.2% yield).

Provenance & Evidence