Water → HCID 11746243, compound

Participants

Reaction Conditions

Reaction Steps

1.37 kg (8.0 mol) of toluenesulphonamide in 6 l of toluene are introduced into a further 20 l HC4 vessel having a distillation bridge. The mixture is treated with 3.2 kg of 45% strength sodium hydroxide solution, 0.8 l of water and 130.5 g of tetrabutylammonium hydrogensulphate, heated to a maximum internal temperature of 40° C. and vacuum is applied. The previously obtained dichloromethane solution (15.21) is then added dropwise in the course of 1.5 hours and the dichloromethane is removed by distillation at 450 mbar at the same time (bath temperature: 60° C.). During the distillation, foam formation takes place. At the end, a solution with an internal temperature of 33-40° C. is present. After completion of the addition, further dichloromethane is removed by distillation until distillate barely still passes over (time: about 85 minutes; internal temperature 40° C. with a bath temperature of 60° C. at the end). The vessel contents are then transferred whilst still warm to a separating funnel and the vessel is rinsed at 50° C. with 5 l of water and 2 l of toluene. Before the phase separation, the solid constituents in the intermediate phase are filtered off with suction and washed with 0.5 l of toluene. The organic phase is washed with 2.4 l of water with stirring, separated off and evaporated to dryness in a rotary evaporator. The solid residue (1758 g) is suspended in 1.6 l of methanol at a bath temperature of 50° C., the suspension is transferred to a 10 l flask having a plane-ground joint and the flask is rinsed with 2.4 l of diisopropyl ether. The mixture is warmed to reflux temperature (59° C.) and stirred for a further 30 minutes under reflux. The suspension is cooled to 0° C., stirred at 0° C. for 1 hour, filtered off with suction and washed with 0.8 l of a cold mixture of methanol/diisopropyl ether (1:1.5). The crystallizate is dried at 50° C./400 mbar under a nitrogen atmosphere.

Provenance & Evidence