Patent ID: 9238603
Filing Date: 2016-01-19
CPC Classification: C07B,C07C

Claim Text:
1. A batch process for the preparation of cis-2,2,4,4-tetramethylcyclobutane-1,3-diol, the process comprising: (A) contacting a monomer selected from 2,2,4,4-tetramethylcyclobutane-1,3-dione, 3-hydroxy-2,2,4,4-tetramethylcyclobutanone, 2,2,4,4-tetramethylcyclobutane-1,3-diol having a starting cis:trans molar ratio of 0:1 to about 2:1, or mixtures thereof with hydrogen in the presence of a reaction solvent in which the resulting cis-2,2,4,4-tetramethylcyclobutane-1,3-diol is partially soluble, and further in the presence of a catalyst comprising about 0.1 to about 10 weight percent ruthenium, based on the total weight of the catalyst, deposited on a support material, under reaction conditions sufficient to produce a reaction product comprising a 2,2,4,4-tetramethylcyclobutane-1,3-diol having a final cis:trans molar ratio of from 2:1 to about 25:1; (B) removing the reaction solvent from the reaction product to obtain 2,2,4,4-tetramethylcyclobutane-1,3-diol solids; (C) dissolving the 2,2,4,4-tetramethylcyclobutane-1,3-diol solids in at least one solvent to form a product solution; and, optionally, (C1) separating the catalyst from the product solution; and, optionally, (D) washing the catalyst at least once; and, optionally, (E) reusing the catalyst, wherein the thermodynamic cis/trans 2,2,4,4-tetramethylcyclobutane-1,3-diol ratio produced by the reaction is greater than the cis/trans 2,2,4,4-tetramethylcyclobutane-1,3-diol solubility ratio in the reaction solvent, and wherein the cis-2,2,4,4-tetramethylcyclobutane-1,3-diol isomer concentration in the reaction solvent is greater than the cis-2,2,4,4-tetramethylcyclobutane-1,3-diol solubility at the reaction temperature.