Sodium Carbonate → 6-(2,4-Difluorophenyl)-5-(4-formylphenyl)-pyrazolo[1,5-a]pyrimidine-3-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

130 mg (0.4 mmol) 5-Chloro-6-(2,4-difluorophenyl)pyrazolo[1,5-a]pyrimidine-3-carboxylic acid methyl ester are given in 1.4 mL dimethoxyethane (no complete dissolution). 0.8 mL Na2CO3 solution (10%) and 66 mg (0.44 mmol) 4-formylphenylboronic acid are added. After addition of 15 mg (0.02 mmol) 1,1′-bis(diphenylphosphino)ferrocenedichloropalladium(II) the reaction mixture is purged 3× with argon and heated at 90° C. for 18 hours (complete dissolution). The reaction mixture is cooled down, treated with water and diluted with dichloromethane. The water phase is extracted once more with dichloromethane and the combined organic phases are washed with brine and dried (Na2SO4). The solvent is removed and the crude product purified via chromatography (silicagel, dichloromethane/methanol). 69.4 mg (41.7%) of the desired aldehyde are obtained.

Provenance & Evidence