Formaldehyde → 6-(2-fluoro-phenyl)-8-{5-[1-(1-methyl-piperidin-4-yl)-1H-pyrazol-4-yl]-pyridin-3-yl}-pyrido[2,3-b]pyrazine

Participants

Reaction Conditions

Reaction Steps

A solution of 85 mg (0.15 mmol) 4-(4-{5-[6-(2-fluoro-phenyl)-pyrido[2,3-b]pyrazin-8-yl]-pyridin-3-yl}-pyrazol-1-yl)-piperidine-1-carboxylic acid tert-butyl ester in 0.5 ml formic acid was treated with 36 μl (0.45 mmol) 35% aqueous formaldehyde solution and heated to 80° C. The reaction mixture was stirred at this temperature for 4 hours. The volume of the reaction mixture was reduced under vacuum and 2 N aqueous NaOH was added. The resulting precipitate was filtered off, washed with water and dried. The residue was chromatographed on a silica gel column with dichloromethane/methanol as eluent yielding 6-(2-fluoro-phenyl)-8-{5-[1-(1-methyl-piperidin-4-yl)-1H-pyrazol-4-yl]-pyridin-3-yl}-pyrido[2,3-b]pyrazine as off-white solid; HPLC/MS: 1.47 min, [M+H] 466.

Provenance & Evidence