Preparation of methyltris(m-sulfonatophenyl) phosphonium iodide trisodium salt and use thereof in carbonylation reactions to prepare carboxylic acids and/or their esters

摘要

In a process for preparing methyltris(m-sulfonatophenyl) phosphonium iodide trisodium salt, the sodium salt of trisulfonated triphenylphosphine and methanol are introduced as the initial charge, a solution of methyl iodide in methanol is added dropwise at elevated temperature, and after an additional reaction time the reaction product is evaporated to dryness in vacuo.PPMethyltris(m- sulfonatophenyl)phosphonium iodide trisodium salt can be used to prepare carboxylic acids and/or their esters by carbonylation of saturated aliphatic alcohols having from 1 to 20 carbon atoms or their halo, ester or ether derivatives over a rhodium catalyst in the presence of water and methyl iodide under a CO partial pressure of from 0.3 to 200 bar at a temperature of from 100° to 240° C., provided methyltris(m- sulfonatophenyl)phosphonium iodide trisodium salt and carboxylic acid are added to the liquid phase prior to carbonylation.