Acetic Anhydride → 1-[3-[2-(cyclopropylamino)-4-pyrimidinyl]-2-(4-fluorophenyl)-5,6-dihydropyrazolo[1,5-b]pyridazin-7(4H)-yl]ethanone

Participants

Reaction Steps

A catalytic amount of 4-dimethylaminopyridine (ca. 5 mg) was added to a solution of N-cyclopropyl-4-[2-(4-fluorophenyl)-4,5,6,7-tetrahydropyrazolo[1,5-b]pyridazin-3-yl]-2-pyrimidinamine (i.e. the product of Step E) (42.1 mg, 0.12 mmol) and acetic anhydride (0.023 mL, 0.24 mmol) in 2 mL of pyridine at room temperature. After 3 h the reaction mixture was diluted with water and extracted with ethyl acetate (3×10 mL). The combined organic phase was dried over magnesium sulfate, filtered and concentrated under reduced pressure. The crude residue was purified by medium pressure liquid chromatography using 20-100% ethyl acetate in hexanes as eluent to give 25 mg of the title product, a compound of the present invention, as a white solid.

Provenance & Evidence