Diisopropylethylamine → HCID 86635174, compound

Participants

Reaction Steps

0.25 g of 4-pyridazine-carboxylic acid (2.01 mmol) and 0.7 g of 4-[4-(2-tert-butyl-6-cyclobutyl-pyrimidin-4-yl)-piperazin-1-yl]-butylamine (2.01 mmol) were dissolved in 25 ml of dichloromethane. 1.04 g of diisopropylethylamine (8.04 mmol), 0.19 g of hydroxybenzotriazole (HOBt, 1.4 mmol), and 0.46 g of N-ethyl-N′-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDCl, 2.4 mmol) were added at 0° C. and the reaction mixture was stirred for 16 h at room temperature. 0.09 g of hydroxybenzotriazole and 0.23 g of N-ethyl-N′-(3-dimethylaminopropyl)-carbodiimide hydrochloride were added and the reaction mixture was stirred 5 h. 25 ml of dichloromethane were added, the organic layer was washed with aqueous saturated sodium chloride, the aqueous phase re-extracted once with dichloromethane. The combined organic phases were dried over magnesium sulfate, filtered, and concentrated to dryness. The crude product was purified by chromatography on silica gel using ethyl acetate and ethyl acetate-methanol (10%). Fractions containing the product were combined, the solvent evaporated, and the residue re-dissolved in 20 ml of ethyl acetate. Treatment with 3.3 ml of 1 N hydrochloride acid in diethyl ether yielded 0.69 g of the title compound as a white solid.

Provenance & Evidence