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