Method of making trimethylene carbonate
AssigneePPG Industries Ohio, Inc.
InventorsMark P. Bowman, Charles B. Kreutzberger
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Abstract
A method of synthesizing trimethylene carbonate, which includes the steps of reacting 1,3-propanediol and phosgene in vapor form, providing a combination of temperature and pressure at which trimethylene carbonate is in its vapor phase, providing a residence time sufficient to react 1,3-propanediol and phosgene to trimethylene carbonate, condensing the trimethylene carbonate vapors, and isolating the condensed trimethylene carbonate. The present method advantageously does not require the use of catalysts and the associated expense of recovering and/or recycling or disposing of catalyst residues.
Claims16
A method of synthesizing trimethylene carbonate comprising:
- (a) contacting 1,3-propanediol in vapor phase with phosgene gas;
- (b) providing the combined reactants of (a) with a combination of temperature and pressure at which trimethylene carbonate is in its vapor phase;
- and
- (c) providing a residence time under the conditions of (b) sufficient to react 1,3-propanediol and phosgene to form trimethylene carbonate.
A method of synthesizing trimethylene carbonate comprising the steps of:
- (a) reacting 1,3-propanediol and phosgene, or a phosgene equivalent, in vapor form, in the presence of non-reactive gas, wherein the molar ratio of 1,3-propanediol to phosgene is from 1.0:0.7 to 1.0:2.0, and wherein the temperature of the reaction vessel is between 100° C. and 400° C., and the pressure in the reaction vessel is less than 20 mm of mercury;
- (b) providing a combination of temperature and pressure at which trimethylene carbonate is in its vapor phase and providing a residence time sufficient to react 1,3-propanediol and phosgene to trimethylene carbonate, wherein the temperature is between 100° C. and 400° C. and the pressure in the reaction vessel is less than 20 mm of mercury, and wherein the residence time is from 1 to 30 seconds;
- and
- (c) condensing the trimethylene carbonate vapors.
Dependencies are inferred from the claim text.