Patents by Inventor Wolfgang Frieben

Wolfgang Frieben 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 preparing 5-vinyl-2-pyrrolidinone and intermediates therefor
    Patent number: 4621145
    Abstract: 4-Amino-5-hexenoic acid is prepared by:(a) reacting 5-oxo-2-pyrrolidine-acetonitrile with hydrogen and dimethylamine in the presence of a palladium catalyst to form N,N-dimethyl-2-[5'-oxo-2'-pyrrolidine]ethylamine;(b) oxidizing N,N-dimethyl-2-[5'-oxo-2'-pyrrolidine]-ethylamine to produce the corresponding N-oxide derivative;(c) pyrolysis of the N-oxide derivative to form 5-vinyl-2-pyrrolidinone;(d) optionally, separating N,N-dimethyl-2-[5'-oxo-2'-pyrrolidine]ethylamine by-product from the 5-vinyl-2-pyrrolidinone product; and(e) hydrolyzing 5-vinyl-2-pyrrolidinone to form 4-amino-5-hexenoic acid.
    Type: Grant
    Filed: November 29, 1983
    Date of Patent: November 4, 1986
    Assignee: Merrell Dow Pharmaceuticals Inc.
    Inventors: Wolfgang Frieben, Fritz Gerhart