Quaternary compound of a tertiary amine and methyl chloride

A process for forming a quaternary ammonium compound, comprising

• (a) placing in a reaction vessel a molten amine which is a tertiary amine of the formula (1a)
• (R.sup.1)N(R.sup.2)(R.sup.3) (1a)
• or an imidazoline of the formula (1b) ##STR7## wherein either of the adjacent pair of carbon atoms is unsubstituted or is substituted with R.sup.4, wherein R.sup.1 is a lower alkyl group containing 1 to 6 carbon atoms, and R.sup.2, R.sup.3 and R.sup.4 are the same or different and each has the formula R.sup.a --O--(CH.sub.2).sub.b -- or R.sup.a --, wherein R.sup.a is a straight or branched alkyl or alkylene radical containing 12 to 24 carbon atoms and 0 to 3 carbon-carbon double bonds, and b is 1 to 4, which molten amine is free of solvent;
• b) reducing pressure within said reaction vessel so that a vacuum is established over said molten amine, which is effective to purge said amine of gases;
• (c) completely quaternizing said molten amine by reacting it with a quaternizing agent consisting of one or more compounds of the formula QX, wherein Q is hydrogen, benzyl, methyl or ethyl and X is a monovalent anion, capable of quaternizing said amine such that the product formed by said reaction contains no unreacted quaternizing compounds, the combination of amine and quaternizing agent constituting a reaction mixture;
• (d) adding solvent to said reaction mixture only if necessary to maintain said reaction mixture in a fluid state before the completion of said quaternization and then not before the viscosity of the reaction mixture is within 10% of no longer being fluid, and only in an amount sufficient to fluidize said reaction mixture and solubilize unreacted quaternizing agent but insufficient to cause a second phase to form in said reaction mixture;
• and
• (e) recovering a product comprising high-purity quaternary ammonium compound of the formula (2a) ##STR8## or the formula (2b) ##STR9## wherein Q, R.sup.1, R.sup.2 and R.sup.3 are as defined above and either of the adjacent pair of carbon atoms in formula (2b) is unsubstituted or is substituted with R.sup.4 as defined above from said reaction vessel.