Hydrochloric Acid → 1-{5-[(1E)-3-Methoxy-1-propenyl]pyridin-2-yl}-5-methyl-1H-pyrazole-4-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

Tetrahydrofuran (4 ml) was added to 1-(5-bromopyridin-2-yl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (620 mg) described in Reference Example 24(2), palladium (II) acetate (45 mg), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (S-Phos) (82 mg), 3-methoxy-1-propenylboronic acid pinacol ester (594 μl) and tripotassium phosphate (1.0 g), and stirred at 100° C. for 4.5 hours. Then, water (5 ml), 4N aqueous solution of sodium hydroxide (5 ml) and ethanol (5 ml) were added to the reaction solution and the mixture was stirred at 80° C. for two hours. The reaction solution was acidified by the addition of water and 1N hydrochloric acid aqueous solution, extracted with ethyl acetate and the solvent was evaporated in vacuo. The resulting solid was washed with water to give the titled compound (300 mg) as a white solid.

Provenance & Evidence