PROCESS AND CATALYST FOR PRODUCING DIALKYL CARBONATES

摘要

The invention relates to a process for preparing dialkyl carbonates which comprises the following steps: a) feeding urea and a primary alcohol to a reaction zone; b) feeding an organotin compound and a high boiling solvent - ether - containing an electron donor atom to the reaction zone; and c) concurrently, in the reaction zone: i) reacting a portion of said primary alcohol and urea in the presence of said organotin compound and said high boiling solvent containing an electron donor atom to produce dialkyl carbonate; ii) removing the dialkyl carbonate and ammonia from said reaction zone as vapour. According to the invention, the homogeneous catalyst used for reacting the urea and primary alcohols to produce dilakyl carbonates comprises a complex of an organotin compound with a bidentate ligand.