Patents by Inventor John R. Durrwachter

John R. Durrwachter 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 phenethanol ethers
    Patent number: 5602285
    Abstract: Substituted phenethanol ethers are prepared in useful yields by the etherification of corresponding substituted phenethyl alcohols with aliphatic primary alcohols. The etherification is carried out by reacting a substituted phenethyl alcohol with an aliphatic primary alcohol in the presence of an acid catalyst at a temperature of at least about 75.degree. C.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: February 11, 1997
    Assignee: Hoechst Celanese Corp.
    Inventors: John R. Durrwachter, Humberto Ramos, Jr., Mohammad Aslam
  • Aldolase catalyzed stereoselective synthesis of arabinohexulose, xyloheptulose, threohexulose and xylohexulose
    Patent number: 5576426
    Abstract: The present invention relates to aldolase catalyzed stereo-selective synthesis of sugars and compositions of matter comprising arabinohexulose, xyloheptulose, threohexulose, and xylohexulose.
    Type: Grant
    Filed: September 8, 1994
    Date of Patent: November 19, 1996
    Assignee: G. D. Searle & Co.
    Inventors: Chi-Huey Wong, John R. Durrwachter, Richard L. Pederson
  • Process for preparing .alpha.-chloro-.alpha.-oximino-4-hydroxyacetophenone
    Patent number: 5292945
    Abstract: A process for the preparation of .alpha.-chloro-.alpha.-oximino-4-hydroxyacetophenone by reacting nitrosyl chloride with a mixture of 4-hydroxyacetophenone and a strong acid catalyst such as hydrogen chloride is disclosed. The nitrosyl chloride is introduced as a gas into the reactor to contact 4-hydroxyacetophenone and said acid catalyst dissolved in a solvent therein.
    Type: Grant
    Filed: February 16, 1993
    Date of Patent: March 8, 1994
    Assignee: Hoechst Celanese Corporation
    Inventors: John R. Durrwachter, Charlet R. Lindley, Graham N. Mott
  • Fructose 1,6-diphosphate aldolase catalyzed steroselective synthesis of sugars
    Patent number: 5143831
    Abstract: A method for preparing optically pure N-containing sugars is disclosed wherein an optically impure chiral aldehyde acceptor is enzymatically condensed with dihydroxyacetone phosphate or dihydroxyacetone with a catalytic amount of inorganic arsenate in the presence of an aldolase to form an N-containing sugar.
    Type: Grant
    Filed: August 30, 1988
    Date of Patent: September 1, 1992
    Assignee: G. D. Searle & Co.
    Inventors: Chi-Huey Wong, John R. Durrwachter, Richard L. Pederson
  • Process for preparing phenethanol ethers by the reduction of corresponding phenylglyoxal acetals
    Patent number: 5124489
    Abstract: Substituted phenethanol ethers are prepared by the catalytic reduction of corresponding substituted phenylglyoxal acetals. The catalytic reduction is carried out by reacting a substituted phenylglyoxal acetal with hydrogen in the presence of an acid catalyst and a metal catalyst. Certain substituted phenylglyoxal acetals, and more particularly, 4-hydroxyphenylglyoxal dialkyl acetals are prepared by reacting 4-hydroxyacetophenone with a primary or a secondary alkyl alcohol in the presence of a hydrogen ion (H+) source and a nitrosonium ion (NO+) source.
    Type: Grant
    Filed: September 6, 1991
    Date of Patent: June 23, 1992
    Assignee: Hoechst Celanese Corporation
    Inventors: John R. Durrwachter, Michael Meier, Graham N. Mott, Werner H. Mueller
  • Formation of hydroxyaromatic ketoacetal from a hydroxyaromatic methylketone and production of 5-(4'-hydroxyphenyl)hydantoin and Dp-hydroxyphenylglycine from 4-hydroxyacetophenone
    Patent number: 5120855
    Abstract: The present invention provides a method for producing a hydroxyaromatic ketoacetal from a hydroxyaromatic methylketone. The invention further provides a method for producing a hydroxyaromatic ketoaldehyde from a hydroxyaromatic ketoacetal. The hydroxyaromatic ketoaldehyde can be further reacted to form a hydantoin, which hydantoin can be hydrolyzed to produce a hydroxyphenylglycine.
    Type: Grant
    Filed: December 13, 1990
    Date of Patent: June 9, 1992
    Assignee: Hoechst Celanese Corporation
    Inventors: Olan S. Fruchey, Graham N. Mott, John R. Durrwachter