Diisopropylethylamine → 4-(5-Methylcarbamoyl-4-o-tolyl-pyridin-2-yl)-piperazine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

A mixture of 8.31 g (31.9 mmol) 6-chloro-N-methyl-4-o-tolyl-nicotinamide, 6.53 g (35.0 mmol) 1-tert-butoxycarbonyl piperazine, 16.7 ml (95.6 mmol) N-ethyldiisopropylamine and a catalytic amount of 4-(N,N-dimethylamino)-pyridine was heated at reflux over night. After cooling to room temperature the mixture was dissolved in dichloromethane and washed with two portions of 0.1 N aqueous hydrochloric acid solution. Drying with sodium sulfate and concentration gave 10.7 g of the crude product. Flash column chromatography afforded 6.28 g (48.0%) of the title compound as an off-white solid.

Provenance & Evidence