Hydrochloric Acid → 1-{5-[4-(2,2-Difluoro-cyclopropylmethyl)-piperazin-1-yl]-pyridin-2-yl}-1,2,3,4-tetrahydroquinoxaline

Participants

Reaction Steps

0.3 g of tert-butyl ester of 4-{5-[4-(2,2-difluoro-cyclopropylmethyl)-piperazin-1-yl]-pyridin-2-yl}-3,4-dihydro-2H-quinoxaline-1-carboxylic acid is put in 5 mL of dioxane, to which 2.32 ml of 4N HCl in dioxane is added. The reaction mixture is stirred at room temperature in a closed environment for 18 h. Once again, 2.32 mL of 4N HCl in dioxane is added, and the reaction mixture is stirred for a further 18 h at room temperature. 2.32 ml of 4N HCl in dioxane is added once again, and the reaction mixture is stirred for a further 18 h at room temperature. After concentration to dryness, the reaction mixture is diluted with a solution of 50 ml of 1N HCl in water and extracted with 100 ml of diethyl ether. The organic phase is washed again with 50 ml of 1N HCl in water. The aqueous phases are then combined, basified with K2CO3 in powder form to pH 10, and extracted 3 times with 50 ml of dichloromethane. The resultant organic phases are combined, washed with a saturated aqueous solution of sodium chloride, dried over MgSO4 and concentrated to dryness. 0.24 g of 1-{5-[4-(2,2-difluoro-cyclopropylmethyl)-piperazin-1-yl]-pyridin-2-yl}-1,2,3,4-tetrahydroquinoxaline is obtained.

Provenance & Evidence