Title:
PRODUCTION OF OXALIC ACID ALKYLENE CYCLIC ESTER AND PURIFICATION
Document Type and Number:
Japanese Patent JP3809215
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a method for economically and efficiently producing a cyclic ester from an oligomer of an alkylene oxalate.
SOLUTION: This method for producing an oxalic acid alkylene cyclic ester by depolymerizing an oligomer of an alkylene oxalate comprises (1) a process for heating a mixture of the oligomer of the alkylene oxalate and at least one high-boiling polar organic solvent having 225-450°C boiling point under normal pressure or reduced pressure to a temperature to cause the depolymerization of the oligomer, (2) a process for dissolving the oligomer in the solvent until the residual ratio of the melt phase of the oligomer reaches ≤0.5, (3) a process for continuously heating the oligomer at the same temperature to depolymerize the oligomer in the solution phase, (4) a process for distilling the formed cyclic ester and the solvent and (5) a process recovering the cyclic ester from the distillate.
Inventors:
Yoshiya Shiiki
Kawakami Shinkai
Kawakami Shinkai
Application Number:
JP6545196A
Publication Date:
August 16, 2006
Filing Date:
February 27, 1996
Export Citation:
Assignee:
Kureha Co., Ltd.
International Classes:
C07D319/12; C07D321/08; C07D321/12; (IPC1-7): C07D319/12; C07D321/08; C07D321/12
Foreign References:
| US3197445 |
Other References:
Carothers, W. H. et al. ,Polymerization and ring formation. V. Glycol esters of oxalic acid,Journal of the American Chemical Society,,1930年,Vol.52, pp.3292-3300
Attorney, Agent or Firm:
Shigeaki Nishikawa
Previous Patent: FACE CLAMP CHUCK
Next Patent: NETWORK INTERFACE BOARD, DIGITAL COPYING MACHINE AND COMPUTER READABLE MEMORY
Next Patent: NETWORK INTERFACE BOARD, DIGITAL COPYING MACHINE AND COMPUTER READABLE MEMORY