Triethylamine → 3-[2-(2,4-difluorophenoxy)-6-oxo-6H-pyrido[1,2-b]pyridazin-5-yl]-4-methoxybenzoic propanoic anhydride

Participants

Reaction Steps

A solution of 3-[2-(2,4-difluorophenoxy)-6-oxo-6H-pyrido[1,2-b]pyridazin-5-yl]-4-methoxybenzoic acid (Intermediate 1, 424 mg, 1.0 mmol) in CH2Cl2 (10 mL) was added triethyl amine (202 mg, 2.0 mmol) and ethylchloroformate (162 mg, 1.8 mmol) at 0° C. The mixture was warmed to ambient temperature and stirred for 10 min. The reaction was complete by LCMS analysis and concentrated in vacuo to yield 3-[2-(2,4-difluorophenoxy)-6-oxo-6H-pyrido[1,2-b]pyridazin-5-yl]-4-methoxybenzoic propanoic anhydride.

Provenance & Evidence