反应详情

The reaction between monoethanolamine hydrochloride and thionylchloride is carried out in a molar ratio of 1:1.05 - 1.2, at 50° to 100°C. for 3 to 10 hours, in water-insoluble solvents such as benzene, toluene, xylene, monochlorobenzene, dichlorobenzene and 1,2-dichloroethane, and in the presence of a catalyst such as dimethylformamide, diethylformamide, N-methylpyrrolidone and pyridine to obtain 2-chloroethylamine hydrochloride with good purity. And, as a result of further investigation, the inventors have found that sulfur dioxide which is produced as a by-product in the course of the chlorination acts as a negative catalyst in the subsequent amidation, i.e. the reaction between the sulfonylhalide (II) and the resulting 2-chloroethyl-amine or salts thereof, and that the yield can be much increased by forcing sulfur dioxide to be removed.