EP0699655B1 — Process for the preparation of quaternary diesters

USPTO Abstract

Disclosed is a process for the preparation of quaternary diesters of the formula: <CHEM> wherein X<-> represents a halogen atom, notably a chlorine atom or a bromine atom, R1 and R2 may be the same or different and have the meaning of an alkyl group having 1 to 3 carbon atoms, a hydroxyethyl group, or be linked together to form an alkylene group having 4 to 6 carbon atoms which may be interrupted by an N atom or O atom, and R3 and R4 may be the same or different and have the meaning of an alkyl group or alkenyl group having 8 to 22 carbon atoms, or be linked together to form an alk(en)ylene group having 8 to 22 carbon atoms, characterised in that a) a secondary amine of the formula R1-NH-R2 is gradually added to and converted with one or more liquid compounds of the formula <CHEM> at a molar ratio in the range of 1,0 : 1,0 and 1,0 : 1,2, after which b) the formed solid amine hydrohalide is separated, followed by c) an aftertreatment, optionally in a solvent, at elevated temperature until the conversion is virtually complete, after which, if so desired, further treatments, such as recrystallisation from an organic solvent, are carried out to achieve a special product form.