Carbon Dioxide → n-Phenylacridan-9-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A solution of N-phenylacridan (14.15 g, 55 mmol) in 200 mL of dry THF under inert atmosphere was cooled to −78° C. and 33.0 mL of 2.5 M n-butyllithium in hexanes (82.5 mmol) was added dropwise over 20 minutes. The solution was stirred at −78° C. for 30 minutes and then warmed to room temperature over 35 minutes. The reaction mixture was again cooled to −78° C. and 350 g of crushed dry ice was added causing a precipitate to form. The reaction was allowed to slowly warm to room temperature causing the reaction to become homogeneous. Stirring under argon was continued at room temperature. The resultant precipitate was collected by suction filtration. The solid was dissolved in 100 mL of water, which was acidified to pH 3 with 2N HCl and extracted with 4×200 mL of ethyl acetate. The combined organics were dried over sodium sulfate and concentrated to dryness to afford 8.72 g of crude product. The reaction mixture filtrate was also concentrated to dryness to afford a solid that was taken up in 300 mL of water. The aqueous solution was acidified, extracted with 3×200 mL of methylene chloride and the combined organics were dried over sodium sulfate and concentrated to afford a second crop of 3.44 g of N-phenylacridan-9-carboxylic acid (73.4%).

Provenance & Evidence