Patents by Inventor Keiji Kagawa

Keiji Kagawa 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).

  • Synthesis of substituted phenylacetic acid
    Patent number: 4220592
    Abstract: A substituted acetonitrile such as .alpha.-isopropyl-p-chlorophenylacetonitrile is hydrolyzed using an acid to produce the corresponding substituted phenylacetic acid such as .alpha.-isopropyl-p-chlorophenylacetic acid in such a manner that, in a lot in any one hydrolysis reaction, (1) the hydrolysis is carried out in at least two steps, (2) an acid to be used in a subsequent first reaction step is a waste acid produced in a previous second reaction step and the subsequent reaction step(s) thereof if any, and (3) an acid to be used in a second reaction step and the subsequent reaction step(s) if any, is the waste acid produced in a previous second reaction step and subsequent reaction step(s), respectively, and a fresh acid.
    Type: Grant
    Filed: July 10, 1978
    Date of Patent: September 2, 1980
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Keiji Kagawa, Naoya Kanda, Fujio Masuko, Hirotoshi Nakanishi