P-Toluenesulfonamide → N-(p-Toluenesulfonyl)-3-pyrroline

Participants

Reaction Conditions

Reaction Steps

A 1.0 l stirred vessel having a bottom discharge valve is charged with 51.3 g (0.3 mol) of p-toluenesulphonamide, 200 ml (1.2 mol) of 6 N sodium hydroxide, 400 ml of toluene and 4.44 g (15 mmol) of tetrabutyl-ammonium chloride and, at an internal temperature of 60° C., 37.5 g (0.3 mol) of cis-1,4-dichloro-2-butene are added dropwise with vigorous stirring over a period of 20 minutes, whereupon the internal temperature rises by 2° C. The mixture is stirred for another hour at 60° C. and another 2 hours at 80° C., the aqueous phase is then separated off and the organic phase is washed at 60° C. with 100 ml of 1 N sulphuric acid and 2×200 ml of water. The organic phase is filtered through a fluted filter moistened with toluene into a crystallisation vessel. Upon cooling to 0° C., 44.8 g of product, melting point 128 to 130° C., are obtained. From the concentrated mother liquor (approx. 20 g), recrystallisation from 100 ml of isopropanol or 60 ml of toluene affords a further 12 to 15 g of product, melting point: 125 to 127° C. Yield: 85 to 90% of theory.

Provenance & Evidence