white to off-white flakes
Triethylamine hydrobromide is used to prepare dimethyl -alfa-diethylaminomaleate by reacting with dimethyl acetylenedicarbosylate. It is involved in the preparation of triphenylpropargylphosphonium bromide.
Equimolar portions of triethylamine and aqueous solutions of HBr in acetone are mixed with cooling. The precipitated salt is washed with anhydrous acetone and dried in vacuum for 1-2hours. [Odinekov et al. J Chem Soc, Faraday Trans 2 80 899 1984.] Recrystallise it from CHCl3 or EtOH. [Beilstein 4 IV 322.]