Dimethyl Carbonate - Production

Production

Dimethyl carbonate can be prepared by the reaction of phosgene with methanol via methyl chloroformate:

COCl₂ + CH₃OH → CH₃OCOCl + HCl

CH₃OCOCl + CH₃OH → CH₃OCO₂CH₃ + HCl

Overall:

COCl₂ + 2 CH₃OH → CH₃OCO₂CH₃ + 2 HCl

This historical synthesis process is undesirable because of phosgene's toxicity and has been largely replaced by other synthesis routes. It is produced industrially by a transesterification of propylene carbonate and methanol, which also affords propylene glycol. A second large scale commercial synthesis route uses a process where carbon monoxide, methanol and oxygen are reacted to form dimethyl carbonate. World production in 1997 was estimated at 1000 barrels a day. Production of dimethyl carbonate worldwide is limited to Asia and Europe.