Potassium Phosphate, Tribasic → HCID 86692411, compound

Participants

Reaction Conditions

Reaction Steps

Isopropenylboronic acid pinacol ester (5.2 ml) was added to 1-(5-bromopyridin-2-yl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (6.2 g) described in Reference Example 24(2), palladium (II) acetate (448 mg), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (S-Phos) (820 mg), tripotassium phosphate (0.6 g) and tetrahydrofuran (20 ml), and the mixture was stirred at 100° C. for 8 hours. Water was added and the reaction mixture was extracted with ethyl acetate and the organic layer was washed with saturated brine, dried over anhydrous sodium sulfate and concentrated in vacuo. To the resultant yellow oil was added 1,4-Dioxane (25 ml) and 10% palladium-carbon (containing ca. 50% of water; 500 mg), and the mixture was stirred under hydrogen atmosphere at room temperature for 5 hours. The reaction solution was filtered through Celite, the filtrate was concentrated in vacuo and the residue was purified with silica gel column chromatography (n-hexane/ethyl acetate). 4N Aqueous solution of sodium hydroxide (5 ml), water (5 ml) and ethanol (10 ml) were added to the resulting oily residue and stirred at 80° C. for 4 hours. The reaction solution was concentrated in vacuo, 1N hydrochloric acid aqueous solution was added to the resulting residue at 0° C., and the precipitated solid was washed with water to give the titled compound (1.56 g) as a pale red solid.

Provenance & Evidence