Patents by Inventor Gunter Murdel

Gunter Murdel 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 the preparation of (6S)- and (6R)-tetrahydrofolic acid
    Patent number: 5324836
    Abstract: For the preparation of (6S)- and (6R)-tetrahydrofolic acid and their addition salts with a sulfonic acid or with sulfuric acid, (6R,S)-tetrahydrofolic acid is reacted with a sulfonic acid or with sulfuric acid, the resulting acid addition salt is fractionally crystallized and, if desired, the (6S)- or (6R)-tetrahydrofolic acid is liberated from the resulting diastereomeric acid addition salts by treatment with a base and isolated.
    Type: Grant
    Filed: April 8, 1993
    Date of Patent: June 28, 1994
    Assignee: Eprova Akteingesellschaft
    Inventors: Hans R. Muller, Martin Ulmann, Josef Conti, Gunter Murdel
  • Process for the preparation of tetrahydrofolates
    Patent number: 5006655
    Abstract: For the preparation of 5,10-methenyl-(6R)-, 5-formyl-(6S)- or 5-methyl-(6S)-tetrahydrofolic acid or salts thereof, 5,10-methenyl-(6R,S)-tetrahydrofolic acid, the inner salt thereof or one of the salts thereof with strong acids is subjected to diastereomer separation by fractional crystallization and, if desired, the resulting 5,10-methenyl-(6R)-tetrahydrofolic acid is converted by treatment with a hydrolyzing agent into 5-formyl-(6S)-tetrahydrofolic acid or by treatment with a reducing agent into 5-methyl-(6S)-tetrahydrofolic acid, and the resulting free acid may be converted into one of its salts by treatment with a base.
    Type: Grant
    Filed: June 29, 1989
    Date of Patent: April 9, 1991
    Assignee: Eprova AG
    Inventors: Hans R. Muller, Martin Ulmann, Josef Conti, Gunter Murdel