Patents by Inventor Yong Tack Lee

Yong Tack Lee 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).

  • Production method for adefovir dipivoxil
    Patent number: 8637669
    Abstract: The present invention relates to an improved method of preparing adefovir dipivoxil of Formula 1. The method of the present invention is characterized by using dimethylsulfoxide as a reaction solvent, and comprises a process of preparing adefovir dipivoxil of Formula 1 by allowing adefovir of Formula 2 to react with chloromethylpivalate at a reaction temperature of 30 to 50° C. under the presence of dimethylsulfoxide and triethylamine solvents.
    Type: Grant
    Filed: September 17, 2009
    Date of Patent: January 28, 2014
    Assignee: CJ Cheiljedang Corporation
    Inventors: Kwang Do Choi, Yong Tack Lee, Myeong Sik Yoon, Hye Suk Hong, Il Hwan Cho, Si Beum Lee, Seong Cheol Bang, Da Won Oh, Min Kyoung Lee
  • PURIFICATION METHOD FOR ADEFOVIR DIPIVOXIL
    Publication number: 20110207928
    Abstract: The present invention relates to a novel method of purifying adefovir dipivoxil of Formula 1. The purification method according to the present invention comprises the steps of dissolving impure adefovir dipivoxil containing byproducts generated during a synthetic reaction, salts thereof or complexes thereof in water or a water-containing mixed solvent; purifying the adefovir dipivoxil solution through a reverse-phase column; and adding a base to the purified adefovir dipivoxil solution and extracting the same with an organic solvent. Further, the present invention provides a method of preparing amorphous adefovir dipivoxil by removing the solvent from the high purity solution of adefovir dipivoxil represented by formula I purified by the above method.
    Type: Application
    Filed: September 10, 2009
    Publication date: August 25, 2011
    Applicant: CJ Cheiljedang Corporation
    Inventors: Il Hwan Cho, Myeong Sik Yoon, Kwang Do Choi, Yong Tack Lee, Si Beum Lee, Seong Cheol Bang, Min Kyoung Lee, Da Won Oh
  • IMPROVED PRODUCTION METHOD FOR ADEFOVIR DIPIVOXIL
    Publication number: 20110207930
    Abstract: The present invention relates to an improved method of preparing adefovir dipivoxil of Formula 1. The method of the present invention is characterized by using dimethylsulfoxide as a reaction solvent, and comprises a process of preparing adefovir dipivoxil of Formula 1 by allowing adefovir of Formula 2 to react with chloromethylpivalate at a reaction temperature of 30 to 50° C. under the presence of dimethylsulfoxide and triethylamine solvents.
    Type: Application
    Filed: September 17, 2009
    Publication date: August 25, 2011
    Applicant: CJ CHEILJEDANG CORPORATION
    Inventors: Kwang Do Choi, Yong Tack Lee, Myeong Sik Yoon, Hye Suk Hong, Il Hwan Cho, Si Beum Lee, Seong Cheol Bang, Da Won Oh, Min Kyoung Lee
  • STABILIZED SOLID DISPERSION OF ADEFOVIR DIPIVOXIL AND PREPARATION METHOD THEREOF
    Publication number: 20110201575
    Abstract: The present invention relates to an amorphous solid dispersion with improved stability comprising 9-[2-[[bis[(pivaloyloxy)methyl]phosphono]methoxy]ethyl]adenine as a nucleotide analogue, a pharmaceutical composition comprising the same, and a method for preparing the same.
    Type: Application
    Filed: September 16, 2009
    Publication date: August 18, 2011
    Applicant: CJ CHEILJEDANG CORPORATION
    Inventors: Yong Tack Lee, Myeong Sik Yoon, Hye Suk Hong, Il Hwan Cho, Tae Kun An, Si Beum Lee, Hae Jong Jang, Mi Kyung Park