Patent ID: 7405330

Claim:
A process for producing polytrimethylene ether glycol comprising: A) forming a reaction mixture comprising (1) a 1,3-propanediol reactant selected from the group consisting of 1,3-propanediol, oligomers of 1,3-propanediol having a degree of polymerization of 2-9, and mixtures of the 1,3-propanediol and said oligomers, (2) at least one polycondensation catalyst and (3) at least one ionic liquid comprised of an ammonium cation and an anion having the Formula: wherein: (i) Z is —(CH 2 ) n —, wherein n is an integer from 2 to 12; (ii) R 2 , R 3 and R 4 taken independently are H, —CH 3 , —CH 2 CH 3 or C 3 to C 6 straight-chain or branched monovalent alkyl; and (iii) A − is R 5 —SO 3 − or (R 6 —SO 2 ) 2 N − ; wherein R 5 and R 6 are independently selected from the group consisting of: (a) —CH 3 , —C 2 H 5 , or C 3 to C 25 straight-chain, branched or cyclic alkane or alkene, optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH 2 and SH; (b) —CH 3 , —C 2 H 5 , or C 3 to C 25 straight-chain, branched or cyclic alkane or alkene comprising one to three heteroatoms selected from the group consisting of O, N and S, and optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH 2 and SH; (c) C 6 to C 25 unsubstituted aryl or unsubstituted heteroaryl having one to three heteroatoms independently selected from the group consisting of O, N and S; and (d) C 6 to C 25 substituted aryl or substituted heteroaryl having one to three heteroatoms independently selected from the group consisting of O, N and S; and wherein said substituted aryl or substituted heteroaryl has one to three substituents independently selected from the group consisting of: (1) —CH 3 , —C 2 H 5 , or C 3 to C 25 straight-chain, branched or cyclic alkane or alkene, optionally substituted with at least one member selected from the group consisting of Cl, Br, F, I, OH, NH 2 and SH, (2) OH, (3) NH 2 , and (4) SH; thereby forming a polyether phase comprising at least one polytrimethylene ether glycol and an ionic liquid phase that comprises the at least one polycondensation catalyst; and B) separating the polyether phase from the ionic liquid phase, thereby forming a separated ionic liquid phase.