Trialkyl phosphine oxide prepn. by alkylating red phosphorus - with gradual alkyl iodide addn. at constant temp.

摘要

Trialkyl phosphine oxides having formula R3PO (I), (where R is 1-16C alkyl) are prepd. by reacting red P with an alkyl iodide and heating in the presence of a catalyst. Novelty consists in adding alkyl iodide gradually to reaction mixt. while keeping temp. const. at 180-230 degrees C. (I) are used as complex-formers, lubricant additives, flame-inhibiting impregnants and intermediates for synthesis of organic P cpds. Yields of (I) are 80-90%. Process time is only 8-10 hrs. Const. alkyl iodide addn. during red P alkylation generates const. catalyst excess and renders process auto-catalytic. Alkyl iodide-dehydrohalogenation is prevented.