Properties of onium salts of phosphorus and nitrogen

Ammonium and phosphonium halides when heated with excess dimethyl or diethyl phosphite can undergo anion exchange as a result of alkylation of halide ions with dialkyl phosphites. Experimental data were obtained, that cast some doubt in the commonly accepted opinion that reactions of tertiary amines and phosphines with dihalides in apolar media result in exclusive formation of monosalts.