1,2-Diaminocyclohexane → N4-(2-Ethylpyrazolo[1,5-a]pyridin-3-yl)tetrahydro-2H-4-pyrancarboxamide

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-ethyl-3-iodopyrazolo[1,5-a]pyridine (350 g, 1.29 mol), tetrahydro-2H-4-pyrancarboxamide (249 g, 1.93 mol), copper iodide (49.0 g, 258 mmol), tripotassium phosphate (hydrate) (546 g, 2.57 mol), 1,2-cyclohexanediamine (mixture of cis and trans) (58.7 g, 514 mmol) and xylene (3500 mL) was stirred while heating at an external temperature of 120° C. (oil bath). The reaction mixture was heated and stirred for 6 hours, and then heating was terminated and upon reaching an internal temperature of 61.5° C., hot water (58° C., 3500 mL) was added to the reaction mixture and stirring was continued overnight. After adding 28% aqueous ammonia (1050 mL) to the reaction mixture and stirring for 1 hour, the precipitate was filtered out and washed with water (1750 mL) and ethyl acetate (1050 mL) and then dried under aeration at 60° C. overnight to afford 280 g of the title compound (major conformer:minor conformer=6:1) (79.6% yield)

Provenance & Evidence