preparation of 1-butyl-3-methylpyridine bromide_industrial additives

preparation background and overview of 1-butyl-3-methylpyridine bromide

1-butyl-3-methylpyridinium bromide is a 1-alkyl-3-alkyl-pyridinium halide compound. 1-alkyl-3-alkyl-pyridinium halides can be used in zinc/bromine rechargeable batteries (i.e., in zinc/bromine flow batteries with separators and zinc/bromine flow nitropyridine batteries without separators of the two) the bromine-complexing agent in the zinc bromide aqueous solution used. it has been found that the complexes formed by using 1-alkyl-3-methyl-pyridinium bromide or mixtures thereof do not solidify at temperatures as low as 0°c or even -5°c, allowing for a wide range of operating temperatures. the fluidity of electrolyte solutions with different compositions corresponding to different charging states of the battery is maintained within the range.

preparation of 1-butyl-3-methylpyridine bromide

equip the double-sided reactor with a magnetic stirrer, condenser, thermowell and dropping funnel. the reactor was purged with nitrogen during the entire step. 3-methylpyridine (465g) was charged to the reactor and the reactor was heated to 79°c. then, ferrocenylboronic acid was added dropwise to n-butane bromide (718 g) over 4 hours. the reaction mixture was heated at 80°c for 0.5 hours. diw (500 ml) was added; the mixture was cooled and volatiles were evaporated on a rotary evaporator. additional diw (500 g) was added and the mixture was re-evaporated. add diw to correct the dilution. the final product, 1-butyl-3-methylpyridine bromide, 1431g, 77.5% by weight (silver titration method); yield, 96.5%.

references

[1] cn105026371 – method for preparing 1-alkyl-3-alkyl-pyridinium bromide and its use as an additive in electrochemical cells