Potassium Carbonate → 4-(3-nitro-2-methoxy-phenyl)-1-(p-tolylsulfonyl)-1H-pyrrole-2-carboxylic acid methyl ester

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Reaction Steps

To a solution of 15 mL of 1,4-dioxane and 5 mL of water was added 2-(2-methoxy-3-nitro-phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 6a (2.05 g, 5.5 mmol) followed by 4-iodo-1-(toluene-4-sulfonyl)-1H-pyrrole-2-carboxylic acid methyl ester 57e (2.03 g, 5 mmol), potassium carbonate (1.38 g, 10 mmol) and tetrakis(triphenylphosphine)palladium (144 mg, 0.125 mmol). Upon completion of the addition, the reaction mixture was reacted at 80° C. for 30 minutes under microwave. The reaction was monitored by TLC until the disappearance of the starting materials. The mixture was concentrated under reduced pressure and the residue was diluted with 20 mL of water. After mixing well, the mixture was extracted with ethyl acetate (20 mL×3). The combined organic extracts were washed with saturated brine, dried over anhydrous magnesium sulfate, filtered to remove the drying agent and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to obtain the title compound 4-(3-nitro-2-methoxy-phenyl)-1-(p-tolylsulfonyl)-1H-pyrrole-2-carboxylic acid methyl ester 57f (1.04 g, yield 48%) as a grey solid.

Provenance & Evidence