Patents by Inventor Zhoujun MENG

Zhoujun MENG 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 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid
    Patent number: 11214553
    Abstract: Disclosed is a method for preparing 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) of formula (II), comprising the following steps: carrying out an alkylation reaction on cyclen in formula (I) and XCH2COOR in the presence of an acid-binding agent in water; adjusting a pH value to separate out a crude product of DOTA; and recrystallizing. The preparation method of the present invention is applicable to large-scale industrial production of DOTA, the whole process does not need to adopt an ion-exchange resin or low-temperature refrigeration mode for purification, and the purity and yield of the product are higher.
    Type: Grant
    Filed: September 18, 2017
    Date of Patent: January 4, 2022
    Assignee: VIWIT PHARMACEUTICAL CO., LTD.
    Inventors: Zhoujun Meng, Yigang He, Yanjun Wei, Yanping Xing
  • METHOD FOR PREPARING 1,4,7,10-TETRAAZACYCLODODECANE-1,4,7,10-TETRAACETIC ACID
    Publication number: 20200347023
    Abstract: Disclosed is a method for preparing 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) of formula (II), comprising the following steps: carrying out an alkylation reaction on cyclen in formula (I) and XCH2COOR in the presence of an acid-binding agent in water; adjusting a pH value to separate out a crude product of DOTA; and recrystallizing. The preparation method of the present invention is applicable to large-scale industrial production of DOTA, the whole process does not need to adopt an ion-exchange resin or low-temperature refrigeration mode for purification, and the purity and yield of the product are higher.
    Type: Application
    Filed: September 18, 2017
    Publication date: November 5, 2020
    Applicant: VIWIT PHARMACEU
    Inventors: Zhoujun MENG, Yigang HE, Yanjun WEI, Yanping XING