Which reaction can I use to transform 2-hydroxyethyl-triethylammonium bromide to 2-hydroxyethyl-triethylammonium chloride?

[Amal]

We have synthesized 2-hydroxyethyl-triethylammonium bromide, then using it we have tried to prepare other salts. First we have used an ion exchange column to obtain 2-hydroxyethyl-triethylammonium chloride, after several tries we didn't get any good results. Following this example : [emim][br] + KOH -> [emim][OH] + KBr [emim][OH] + CH3COOH -> [emim][CH3COO] + H2O We have tried to prepare 2-hydroxyethyl-triethylammonium acetate but for some reasons, the reaction didn't take place. Can anyone help me to find an alternative method to synthesize those salts using 2-hydroxyethyl-triethylammonium bromid

[BabcockHall]

How much molar excess ion exchange resin did you use? Which resin did you use? Bromide binds a little bit more strongly to some exchangers than chloride does, so that fact should help the exchange.