Patents by Inventor Masatoshi Tukamoto

Masatoshi Tukamoto 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).

  • Optically active N-substituted phenylalaninols and use thereof
    Patent number: 4536601
    Abstract: Optically active N-substituted phenylalaninols of the formula (I): ##STR1## wherein R is isopropyl, 1-ethylpropyl, cyclopentyl, cyclohexyl, cycloheptyl, 4-methylbenzyl, 4-methoxybenzyl, or 3,4-methylenedioxybenzyl; and acid addition salts thereof which are useful as a resolving agent, and a process for preparing D-3-acetylthio-2-methylpropionic acid which comprises reacting DL-3-acetylthio-2-methylpropionic acid with an optically active N-substituted phenylalaninol of the formula (I) to form diastereomeric salts, subjecting the formed diastereomeric salts to a fractional crystallization from a solvent to separate the D-acid salt from the L-acid salt, and then decomposing the D-acid salt with a mineral acid to give D-3-acetylthio-2-methylpropionic acid.
    Type: Grant
    Filed: September 23, 1983
    Date of Patent: August 20, 1985
    Assignee: Dainippon Pharmaceutical Co., Ltd.
    Inventors: Masatoshi Tukamoto, Tadahiro Sawayama