Patents by Inventor Hirohisa KITAHARA

Hirohisa KITAHARA 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-(1-tert-butoxycarbonyl-4-piperidylacetyl)-4-mesyloxypiperidine and 1-(1-tert-butoxycarbonyl-4-piperidylacetyl)-4-mesyloxypiperidine
    Patent number: 11827603
    Abstract: The object of the present invention is to provide 1-(1-tert-butoxycarbonyl-4-piperidylacetyl)-4-mesyloxypiperidine having a low content of impurities The object can be solved by a method for preparing 1-(1-benzyl-4-piperidylacetyl)-4-hydroxypiperidine, comprising the steps of: (1) reductively reacting 1-benzyl-4-piperidylidene acetic acid ethyl ester represented by the formula [1]: to obtain 1-benzyl-4-piperidyl acetic acid ethyl ester represented by the formula [2]: (2) adding an ammonium chloride aqueous solution and an organic solvent to the liquid containing 1-benzyl-4-piperidyl acetic acid ethyl ester, mixing the whole, and separating into an organic layer and an aqueous layer, (3) collecting 1-benzyl-4-piperidyl acetic acid ethyl ester from the organic layer, and (4) reacting the obtained 1-benzyl-4-piperidyl acetic acid ethyl ester with 4-hydroxypiperidine represented by the formula [3]: in the presence of base, to obtain 1-(1-benzyl-4-piperidylacetyl)-4-hydroxypiperidine repr
    Type: Grant
    Filed: January 18, 2019
    Date of Patent: November 28, 2023
    Assignee: YUKI GOSEI KOGYO CO., LTD.
    Inventors: Kiyono Nakagawa, Yoshihiro Ito, Hirohisa Kitahara
  • METHOD FOR PRODUCING 1-(1-TERT-BUTOXYCARBONYL-4-PIPERIDYLACETYL)-4- MESYLOXYPIPERIDINE AND 1-(1-TERT-BUTOXYCARBONYL-4-PIPERIDYLACETYL)-4-MESYLOXYPIPERIDINE
    Publication number: 20220388959
    Abstract: The object of the present invention is to provide 1-(1-tert-butoxycarbonyl piperidylacetyl)-4-mesyloxypiperidine having a low content of impurities The object can be solved by a method for preparing 1-(1-benzyl piperidylacetyl)-4-hydroxypiperidine, comprising the steps of: (1) reductively reacting 1-benzyl-4-piperidylidene acetic acid ethyl ester represented by the formula [1]: to obtain 1-benzyl-4-piperidyl acetic acid ethyl ester represented by the formula [2]: (2) adding an ammonium chloride aqueous solution and an organic solvent to the liquid containing 1-benzyl-4-piperidyl acetic acid ethyl ester, mixing the whole, and separating into an organic layer and an aqueous layer, (3) collecting 1-benzyl-4-piperidyl acetic acid ethyl ester from the organic layer, and (4) reacting the obtained 1-benzyl-4-piperidyl acetic acid ethyl ester with 4-hydroxypiperidine represented by the formula [3]: in the presence of base, to obtain 1-(1-benzyl-4-piperidylacetyl)-4-hydroxypiperidine represented by the for
    Type: Application
    Filed: January 18, 2019
    Publication date: December 8, 2022
    Applicant: YUKI GOSEI KOGYO CO., LTD.
    Inventors: Kiyono NAKAGAWA, Yoshihiro ITO, Hirohisa KITAHARA