Pyrrolidine → N-acetyl-3-methyl-4-(pyrrolidin-1-yl-carbonyl)-aniline

Participants

Reaction Conditions

Reaction Steps

25.0 g (124 mmol) N-acetyl-4-amino-2-methyl-benzoic acid are combined with 3 drops DMF in 1000 ml dichloromethane and a solution of 21.0 ml (30.56 g, 241 mmol) oxalyl chloride in 100 ml TEA is added dropwise with stirring and cooling in the ice bath. Then the mixture is heated to 50° C. for 4.5 hours. The reaction mixture is filtered and the filtrate is evaporated down completely i. vac. The residue is taken up in 100 ml dichloromethane and this solution is added dropwise to a mixture of 10.4 ml (8.86 g, 125 mmol) pyrrolidine and 34.4 ml (25.0 g, 247 mmol) TEA in 500 ml dichloromethane with stirring and cooling in the ice bath. The mixture is stirred for 16 hours at ambient temperature. After filtering the filtrate is washed with 1-molar hydrochloric acid and sat. sodium chloride solution, combined with activated charcoal and dried over sodium sulphate. After evaporation i. vac. the residue is purified by chromatography on silica gel.

Provenance & Evidence