Patents by Inventor Wei-Guo Gao

Wei-Guo Gao 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 of citalopram, intermediate therefor and production method of the intermediate
    Patent number: 7119215
    Abstract: A compound of formula [V] is prepared by oxidizing a compound of formula [III]. Citalopram can be industrially and economically produced and at a high yield by converting a compound of formula [V], which is prepared from a compound of formula [III], to a compound of formula [VI], and then alkylating the compound of formula [VI] to form citalopram.
    Type: Grant
    Filed: February 28, 2002
    Date of Patent: October 10, 2006
    Assignee: Sumitomo Chemical Company Limited
    Inventors: Tetsuya Ikemoto, Wei-Guo Gao, Masami Igi
  • Production method of citalopram, intermediate therefor and production method of the intermediate
    Publication number: 20040230066
    Abstract: Citalopram can be industrially and economically produced and at a high yield by reacting a compound of the following formula [VI] with 3-(dimethylamino)propyl chloride in the presence of at least one of N,N,N′,N′-tetramethylethylenediamine and 1,3-dimethyl-2-imidazolidinone and a condensing agent. The compound of the following formula [III], which is a key compound for the production of citalopram, can be easily produced by subjecting the compound of the following formula [II] to reduction and cyclization.
    Type: Application
    Filed: June 14, 2004
    Publication date: November 18, 2004
    Applicant: Sumika Fine Chemicals Co., Ltd.
    Inventors: Tetsuya Ikemoto, Wei-Guo Gao, Masami Igi
  • Production method of 2-cyclohexyl-2-hydroxy-2-phenylacetic acid intermediate therefor and production method thereof
    Patent number: 6777576
    Abstract: The present invention relates to production of 2-cyclohexyl-2-hydroxy-2-phenylacetic acid useful as an intermediate for pharmaceutical products, by an industrial means, economically, safely in a good yield. Novel 2-(2′-cyclohexen-1′-yl)-2-hydroxy-2-phenylacetic acid ester obtained by reacting cyclohexene and benzoylformic acid ester in the presence of a Lewis acid is hydrolyzed and reduced to give 2-cyclohexyl-2-hydroxy-2-phenylacetic acid.
    Type: Grant
    Filed: November 6, 2001
    Date of Patent: August 17, 2004
    Assignee: Sumika Fine Chemicals Co., Ltd.
    Inventors: Tetsuya Ikemoto, Wei-Guo Gao, Mitsuhiro Takeda, Masami Igi
  • Production method of citalopram, intermediate therefor and production method of the intermediate
    Publication number: 20040138497
    Abstract: Citalopram can be industrially and economically produced and at a high yield by reacting a compound of the following formula [VI] with 3-(dimethylamino)propyl chloride in the presence of at least one of N,N,N′,N′-tetramethylethylenediamine and 1,3-dimethyl-2-imidazolidinone and a condensing agent. The compound of the following formula [III], which is a key compound for the production of citalopram, can be easily produced by subjecting the compound of the following formula [II] to reduction and cyclization.
    Type: Application
    Filed: December 23, 2003
    Publication date: July 15, 2004
    Applicant: Sumika Fine Chemicals Co., Ltd.
    Inventors: Tetsuya Ikemoto, Wei-Guo Gao, Masami Igi
  • Production method of 2-cyclohexyl- 2-hydroxy-2-phenylacetic acid intermediate therefor and production method thereof
    Publication number: 20030013911
    Abstract: The present invention relates to production of 2-cyclohexyl-2-hydroxy-2-phenylacetic acid useful as an intermediate for pharmaceutical products, by an industrial means, economically, safely in a good yield. Novel 2-(2′-cyclohexen-1′-yl)-2-hydroxy-2-phenylacetic acid ester obtained by reacting cyclohexene and benzoylformic acid ester in the presence of a Lewis acid is hydrolyzed and reduced to give 2-cyclohexyl-2-hydroxy-2-phenylacetic acid.
    Type: Application
    Filed: November 6, 2001
    Publication date: January 16, 2003
    Applicant: Sumika Fine Chemicals Co., Ltd.
    Inventors: Tetsuya Ikemoto, Wei-Guo Gao, Mitsuhiro Takeda, Masami Igi
  • Production methods of citalopram and an intermediate therefor
    Patent number: 6458975
    Abstract: Citalopram can be industrially and economically produced and at a high yield by reacting a compound of the following formula [VI] with 3-(dimethylamino)propyl chloride in the presence of at least one of N,N,N′,N′-tetramethylethylenediamine and 1,3-dimethyl-2-imidazolidinone and a condensing agent.
    Type: Grant
    Filed: November 28, 2001
    Date of Patent: October 1, 2002
    Assignee: Sumika Fine Chemicals Co., Ltd.
    Inventors: Tetsuya Ikemoto, Wei-Guo Gao, Nobuhiro Arai, Masami Igi
  • Production method of citalopram, intermediate therefor and production method of the intermediate
    Patent number: 6433196
    Abstract: Citalopram can be industrially and economically produced and at a high yield by reacting a compound of the following formula [VI] with 3-(dimethylamino)propyl chloride in the presence of at least one of N,N,N′,N′-tetramethylethylenediamine and 1,3-dimethyl-2-imidazolidinone and a condensing agent. The compound of the following formula [III], which is a key compound for the production of citalopram, can be easily produced by subjecting the compound of the following formula [II] to reduction and cyclization.
    Type: Grant
    Filed: September 5, 2000
    Date of Patent: August 13, 2002
    Assignee: Sumika Fine Chemicals Co., Ltd.
    Inventors: Tetsuya Ikemoto, Wei-Guo Gao, Nobuhiro Arai, Masami Igi
  • Production method of citalopram, intermediate therefor and production method of the intermediate
    Publication number: 20020095051
    Abstract: Citalopram can be industrially and economically produced and at a high yield by reacting a compound of the following formula [VI] with 3-(dimethylamino)propyl chloride in the presence of at least one of N,N,N′,N′-tetramethylethylenediamine and 1,3-dimethyl-2-imidazolidinone and a condensing agent. The compound of the following formula [III], which is a key compound for the production of citalopram, can be easily produced by subjecting the compound of the following formula [II] to reduction and cyclization.
    Type: Application
    Filed: February 28, 2002
    Publication date: July 18, 2002
    Applicant: Sumika Fine Chemicals Co., Ltd.
    Inventors: Tetsuya Ikemoto, Wei-Guo Gao, Nobuhiro Arai, Masami Igi
  • PRODUCTION METHOD OF CITALOPRAM, INTERMMEDIATE THEREFOR AND PRODUCTION METHOD OF THE INTERMEDIATE
    Publication number: 20020062040
    Abstract: Citalopram can be industrially and economically produced and at a high yield by reacting a compound of the following formula [VI] with 3-(dimethylamino)propyl chloride in the presence of at least one of N,N,N′,N′-tetramethylethylenediamine and 1,3-dimethyl-2-imidazolidinone and a condensing agent. The compound of the following formula [III], which is a key compound for the production of citalopram, can be easily produced by subjecting the compound of the following formula [II] to reduction and cyclization.
    Type: Application
    Filed: November 28, 2001
    Publication date: May 23, 2002
    Applicant: Sumika Fine Chemicals Co., Ltd.
    Inventors: Tetsuya Ikemoto, Wei-Guo Gao, Nobuhiro Arai, Masami Igi