Patent ID: 7408070

Claim:
A method for purifying an oxybisphthalimide having structure (II) wherein R 1 is a C 1 -C 8 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical; said method comprising the steps of: (a) providing a first solution comprising at least one oxybisphthalimide (II), at least one solvent, and at least one organic phase transfer catalyst; and (b) contacting the first solution with a solid inorganic adsorbent material, said solid inorganic adsorbent material having a total pore volume of about 0.5 milliliters/gram or greater, and a cumulative pore volume distribution of about 20 percent or greater of particles having a pore diameter in a range between about 3 nanometers and about 20 nanometers; to provide a second solution of the oxybisphthalimide (II), which is substantially free of the organic phase transfer catalyst.