Purification of diethylene glycol monoethyl ether

摘要

The present invention provides a method for purifying diethylene glycol monoethyl ether, which is commonly known as Carbitol TM or Ethyl Carbitol TM . The method according to the present invention includes combining n-heptanol as an azeotrope-forming agent to crude diethylene glycol monoethyl ether which contains ethylene glycol as an impurity to form a mixture, subjecting the mixture to distillation whereby an overhead product comprising an azeotrope of ethylene glycol and n-heptanol and a bottoms product are produced, and recovering purified diethylene glycol monoethyl ether from the bottoms product. By practicing the method of the present invention, the ethylene gylcol content of diethylene glycol monoethyl ether can be reduced from thousands of parts per million to less than about twenty-five parts per million such that the purified diethylene glycol monoethyl ether is suitable for use as a solvent in pharmaceutical manufacturing applications.