Patents by Inventor Frederic C. Chang

Frederic C. Chang 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).

  • Process for production of chenodeoxycholic acid
    Patent number: 4425273
    Abstract: A process for producing chenodeoxycholic acid of the following formula ##STR1## which comprises reducing a 12-oxocholanic acid tosylhydrazone compound of the following formula ##STR2## wherein R.sub.1 and R.sub.2 are identical or different and each represents an acyl group, Ts represents a tosyl group, and R.sub.3 represents an alkyl group, in an organic acid solvent, and subjecting the reduction product to a hydrolyzing treatment.
    Type: Grant
    Filed: June 18, 1982
    Date of Patent: January 10, 1984
    Inventors: Takeshi Iida, Frederic C. Chang