Potassium Phosphate, Tribasic → HCID 178497013, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 42 mg (0.1 mmol) of 5-(4-bromo-phenyl)-6-cyclohexyl-7-oxo-4,7-dihydro-pyrazolo[1,5-a]pyrimidine-2-carboxylic acid methyl ester, 21 mg (0.15 mmol) of 3,5-dimethyl-isoxazoleboronic acid, 7.3 mg (0.01 mmol) of Pd catalyst, and 63 mg (0.3 mmol) of potassium phosphate in 1 mL of 1,4-dioxane was shaken at 95° C. in a sandbath overnight. The reaction mixture was then diluted with dichloromethane, filtered through a small pad of Celite, dried over sodium sulfate and evaporated to give a residue, which was purified via reverse-phase chromatography (Gilson) to afford desired 6-cyclohexyl-5-[4-(3,5-dimethyl-isoxazol-4-yl)-phenyl]-7-oxo-4,7-dihydro-pyrazolo[1,5-a]pyrimidine-2-carboxylic acid methyl ester as a solid as indicated by LC-MS—calcd for C25H26N4O4 [M++H]+: 447.19, found: 447.3. This material was then converted to 6-cyclohexyl-5-[4-(3,5-dimethyl-isoxazol-4-yl)-phenyl]-7-oxo-4,7-dihydro-pyrazolo[1,5-a]pyrimidine-2-carboxylic acid (591) via the well known LiOH saponification protocol (37% yield over 2 steps); LC-MS—calcd for C24H24N4O4 [M++H]+: 433.18, found: 433.1.

Provenance & Evidence