A general method for the quaternization of N,N-dimethyl benzylamines with long chain n-alkylbromides

Benzalkonium bromides (BAK) are an important class of cationic surfactants with both industrial and commercial uses. They are used as preservatives for ophthalmic, nasal and parenteral products and they are also used as a topical antiseptic and medical equipment disinfectant. In this work a universal method for the preparation of these compounds is described. Using quaternization of N,N-dimethylbenzylamines with long-chain n-alkylbromides we have prepared C8, C10, C12, C14, C16, C18 and C20 homologues of the benzalkonium bromides (BAK).