Patents by Inventor Arun S.

Arun S. has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Methods for purifying 2-aryl-3,3-bis(hydroxyaryl)phthalimidines
    Publication number: 20070135612
    Abstract: A method for purifying a 2-aryl-3,3-bis(hydroxyaryl)phthalimidine comprises contacting a crude 2-aryl-3,3-bis(hydroxyaryl)phthalimidine with a purification agent, removing a 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine compound from the crude 2-aryl-3,3-bis(hydroxyaryl)phthalimidine, and producing a purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine product comprising less than 200 parts per million of the 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine compound. The purification agent is selected from the group consisting of an acidic material, an organic acid chloride, an organic anhydride, or a combination thereof. The 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine compound has a formula: wherein each R1 is independently selected from a group consisting of a hydrocarbyl radical, a nitro radical, and a halogen atom; “a” is an integer from 0 to 4; and Ar1 and Ar2 are independently at each occurrence an aromatic radical.
    Type: Application
    Filed: December 14, 2005
    Publication date: June 14, 2007
    Inventors: Balakrishnan Ganesan, Pradeep Nadkarni, Arun S., Ramanarayanan G.V., Suresh Shanmugam, Gurram Kishan, Ravindra Singh