Preparation of Cationic Surfactants from sec- Chloroalkanes and Alkanol Amines

Abstract

In recent years, n-paraffins and n-olefins have been attracted interest as the lipophilic group of surfactants. And secondary chloroalkanes became easy to obtain from these materials by commercial process.The method of preparation of cationics from primary chloroalkanes with pyridine have been commercially carried out from past time and is being practiced currently. But the method of preparation of cationics from secondary chloroalkanes with lower amines did not come into operation, because the reation was difficult, and olefins were formed as by-product. The authors attempted the reaction between secondary chloroalkanes and alkanolamines and found that N-β-oxyethyl-2-amino alkanes can be prepared quite easily by a new one-step process. Chloroalkanes were insoluble in alkanolamines, but these materials reacted easily under the condition of heterogenous agitating system by homomixer. Good yield of N-β-oxyethyl-2-amino alkanes were obtained under the condition; 1 atm., 150160°C, without catalyst, without solvent. After reaction, the purification of the product was very easy because the reaction product was separated almost quantitatively from the lower phase of excess ethanolamines and these salts of hydrochloride. The hydrochloride produced by the dehydrochlorination, reacted with excess ethanolamines selectively. Ethanolamines were reproduced easily from these salts of hydrochloride by the addition of sodium hydroxide.The reaction rate was retarded by increased chain length of chloroalkanes, and the yield decreased according with shift of the substituted position of chlorine to the center.From these results, it was concluded that 2-chloroalkanes prepared from α-olefins are most suitable source materials in this reaction.