Patents by Inventor Yashio Takakuwa

Yashio Takakuwa 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 of preparing .alpha.-aromatic propionic acids and intermediates thereof
    Patent number: 4577025
    Abstract: A method for the preparation of an ester of .alpha.-thio-.alpha.-aromatic propionic acid derivatives of the formula: ##STR1## wherein R.sup.1 is alkyl, phenyl or benzothiazolyl, R.sup.2 is alkyl and Ar is an aromatic substituent.The method comprises reacting an ester of .alpha.-chloro-.alpha.-thiopropionic acid of the formula: ##STR2## with an aromatic compound of the formula ARH, in the presence of a Lewis acid. The method provides good reactivity and positional selectivity in the Friedel-Crafts reaction. Many esters of the formula (2) are useful as pharmaceuticals, agricultural chemicals, perfumes or their intermediates.
    Type: Grant
    Filed: August 26, 1983
    Date of Patent: March 18, 1986
    Assignee: Nissan Chemical Industries, Ltd.
    Inventors: Kazutaka Arai, Yoshio Ohara, Yashio Takakuwa, Toyoko Iizumi