Patents by Inventor Tangjun Wang

Tangjun Wang 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).

  • Preparation method of carfentrazone-ethyl
    Patent number: 8957220
    Abstract: A preparation method of carfentrazone-ethyl comprises steps of: reacting 1-(5-amino-4-chloro-2-fluorophenyl)-4-difluoromethyl-3-methyl-1H-1,2,4-triazol-5-one with acrylic acid through a diazo arylation reaction to give 2-chloro-3-{2-chloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,3-triazol-1-yl]-4-fluorophenyl}propionic acid; and reacting the 2-chloro-3-{2-chloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,3-triazol-1-yl]-4-fluorophenyl}propionic acid with ethanol through an esterification reaction in a presence of an acidic catalyst to give carfentrazone-ethyl.
    Type: Grant
    Filed: January 12, 2012
    Date of Patent: February 17, 2015
    Assignees: Zhejiang Zhuji United Chemicals Co., Ltd, Luzhou Oriental Agrochemicals Co., Ltd.
    Inventors: Qunzhen Guo, Guoping Cai, Tangjun Wang, Jiandi Yu, Wei Liu
  • Preparation method of carfentrazone-ethyl
    Publication number: 20130345435
    Abstract: A preparation method of carfentrazone-ethyl comprises steps of: reacting 1-(5-amino-4-chloro-2-fluorophenyl)-4-difluoromethyl-3-methyl-1H-1,2,4-triazol-5-one with acrylic acid through a diazo arylation reaction to give 2-chloro-3-{2-chloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,3-triazol-1-yl]-4-fluorophenyl}propionic acid; and reacting the 2-chloro-3-{2-chloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,3-triazol-1-yl]-4-fluorophenyl}propionic acid with ethanol through an esterification reaction in a presence of an acidic catalyst to give carfentrazone-ethyl.
    Type: Application
    Filed: January 12, 2012
    Publication date: December 26, 2013
    Inventors: Qunzhen Guo, Gouping Cai, Tangjun Wang, Jiandi Yu, Wei Liu