Dimethylformamide → HCID 86692437, compound

Participants

Reaction Conditions

Reaction Steps

Methylboronic acid (457 mg), tripotassium phosphate (3.40 g) and 1,1′-bis(diphenylphosphino)ferrocene-palladium (II) dichloride dichloromethane complex (296 mg) were added to a N,N-dimethylformamide solution (36 ml) of 1-(5-bromo-3-chloropyridin-2-yl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (2.50 g) described in Reference Example 44(2), and the mixture was stirred at 100° C. for three hours. Methylboronic acid (154 mg) and 1,1′-bis(diphenylphosphino)ferrocene-palladium (II) dichloride dichloromethane complex (103 mg) were subsequently added and the mixture was further stirred for three hours. The reaction solution was cooled to room temperature and left stand for 16 hours, and methylboronic acid (153 mg) and 1,1′-bis(diphenylphosphino)ferrocene-palladium (II) dichloride dichloromethane complex (114 mg) were further added and the mixture was stirred again at 100° C. for five hours. After completion of the reaction, the reaction solution was cooled to room temperature, diluted with water and extracted with ethyl acetate three times. The organic layer was washed with water, dried over anhydrous sodium sulfate and concentrated. The resulting residue was purified with silica gel column chromatography (n-hexane/ethyl acetate) to give 1-(3-chloro-5-methylpyridin-2-yl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (1.03 g).

Provenance & Evidence