Process for preparing quaternary alkammonium halides
Alkylammonium halides of the formula are described wherein the alkylammonium halide is prepared by reacting an alkylamine hydrohalide salt and its corresponding free amine with at least two equivalents of an epihalohydrin.
1. A process for making an alkylammonium halide of the formula (I):
[(R) y —N—[CH 2 —CH(OH)—CH 2 —Z] 4-y ] + X − (I)
wherein y is 1 or 2;
Z is halogen;
X— is halide; and
R, at each occurrence, is independently H or C 1 -C 18 alkyl, provided that at least one R is C 1 -C 18 ,
the process comprising:
combining a mono or di alkylamine hydrohalide salt and its corresponding free amine to form a pre-mixture; and
reacting said pre-mixture with at least two equivalents of an epihalohydrin.
2. The process of claim 1 , further comprising combining the alkylamine hydrohalide salt and its corresponding free amine previous to combination with the epihalohydrin.
3. The process of claim 2 , further comprising combining the alkylamine hydrohalide salt and its corresponding free amine in a proportion to achieve a pH less than about 10 in the resulting pre-mixture.
4. The process of claim 2 , further comprising combining the alkylamine hydrohalide salt and its corresponding free amine in a proportion to achieve a pH less than about 9 in the resulting pre-mixture.
5. The process of claim 2 , further comprising combining the alkylamine hydrohalide salt and its corresponding free amine in a proportion to achieve a pH less than about 8 in the resulting pre-mixture.
6. The process of claim 3 , wherein the pre-mixture is substantially free of alcohol solvent.
7. The process of claim 1 , wherein y is 2.
8. The process of claim 1 , wherein R is unsubstituted C1-C3 alkyl.
9. The process of claim 1 , wherein the alkylamine is a dialkylamine.
10. The process of claim 1 , wherein the alkylammonium halide of formula (I) is bis(3-chloro-2-hydroxypropyl)dimethylammonium chloride.
11. The process of claim 1 , wherein the epihalohydrin is epicholorhydrin.
12. The process of claim 1 , wherein the epihalohydrin to amine plus hydrohalide mole ratio is at least 2.05:1.
13. The process of claim 1 , wherein the epihalohydrin to amine plus hydrohalide mole ratio is about 3:1.
14. The process of claim 1 , further comprising extracting alkylammonium halide of the formula (I) with a halogenated solvent.
15. The process of claim 14 , wherein the product of the process comprises no more than about 20 wt. percent of impurities.
16. The process of claim 14 , wherein the product of the process comprises no more than about 15 wt. percent of impurities.
17. The process of claim 14 , wherein the product of the process comprises no more than about 10 wt. percent, of impurities.
18. The process of claim 14 , wherein the product of the process comprises no more than about 4 wt. percent of impurities.