Patents by Inventor Lianchao ZHOU

Lianchao ZHOU 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).

  • Method for preparing apremilast
    Patent number: 10781173
    Abstract: Provided is a method for preparing apremilast of formula I. Method one: (S)-1-(3-ethoxy-4-methoxyphenyl)-2-(methylsulfonyl)ethylamine N-acetyl-L-leucine salt of formula II is reacted with 3-acetylaminophthalic anhydride of formula III in an aprotic solvent to produce the compound of formula I; method two: (S)-1-(3-ethoxy-4-methoxyphenyl)-2-(methylsulfonyl)ethylamine N-acetyl-L-leucine salt of formula II is reacted with 3-acetylaminophthalic anhydride of formula III in an organic solvent in the presence of an organic alkali or an alkali metal hydride to produce the compound of formula I. The method for preparing apremilast requires inexpensive raw materials and reagents, is suitable for industrial production, and has great economic effects.
    Type: Grant
    Filed: June 30, 2017
    Date of Patent: September 22, 2020
    Assignee: ZHEJIANG HUAHAI PHARMACEUTICAL CO., LTD
    Inventors: Xiaoqiu Du, Lianchao Zhou, Jiegen Liu
  • METHOD FOR PREPARING APREMILAST
    Publication number: 20190248740
    Abstract: Provided is a method for preparing apremilast of formula I. Method one: (S)-1-(3-ethoxy-4-methoxyphenyl)-2-(methylsulfonyl)ethylamine N-acetyl-L-leucine salt of formula II is reacted with 3-acetylaminophthalic anhydride of formula III in an aprotic solvent to produce the compound of formula I; method two: (S)-1-(3-ethoxy-4-methoxyphenyl)-2-(methylsulfonyl)ethylamine N-acetyl-L-leucine salt of formula II is reacted with 3-acetylaminophthalic anhydride of formula III in an organic solvent in the presence of an organic alkali or an alkali metal hydride to produce the compound of formula I. The method for preparing apremilast requires inexpensive raw materials and reagents, is suitable for industrial production, and has great economic effects.
    Type: Application
    Filed: June 30, 2017
    Publication date: August 15, 2019
    Inventors: Xiaoqiu DU, Lianchao ZHOU, Jiegen LIU