Patents by Inventor Hugh L. Dryden, Jr.

Hugh L. Dryden, Jr. 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).

  • One-pot process for the preparation of .alpha.-L-aspartyl-L-phenylalanine methyl ester hydrochloride
    Patent number: 5476961
    Abstract: A one-pot process for the preparation of .alpha.-L-aspartyl-L-phenylalanine methyl ester hydrochloride is disclosed (.alpha.-APM(HCl)). .alpha.-APM(HCl) is an intermediate in the preparation of aspartame.
    Type: Grant
    Filed: June 21, 1993
    Date of Patent: December 19, 1995
    Assignee: The NutraSweet Company
    Inventors: John B. Hill, Yefim Gelman, Hugh L. Dryden, Jr., Robert Erickson, Kuang Hsu, Mark R. Johnson
  • One-pot process for the preparation of .alpha.-L-aspartyl-L-phenylalanine methyl ester hydrochloride
    Patent number: 5053532
    Abstract: A one-pot process for the preparation of .alpha.-L-aspartyl-L-phenylalanine methyl ester hydrochloride is disclosed (.alpha.-APM(HCl)). .alpha.-APM(HCl) is an intermediate in the preparation of aspartame.
    Type: Grant
    Filed: July 3, 1990
    Date of Patent: October 1, 1991
    Assignee: The Nutra Sweet Company
    Inventors: John B. Hill, Yefim Gelman, Hugh L. Dryden, Jr., Robert Erickson, Kuang Hsu, Mark R. Johnson
  • Preparation of N-formyl-L-aspartic anhydride
    Patent number: 4945172
    Abstract: N-formyl-L-aspartic anhydride is prepared using a minimum excess of formic acid. Acetic anhydride and a C.sub.3 -C.sub.6 secondary alcohol are added to the reaction mixture to consume excess formic acid. The reaction is suitable for further reactions without modification.
    Type: Grant
    Filed: November 28, 1989
    Date of Patent: July 31, 1990
    Assignee: The Nutra Sweet Company
    Inventors: John B. Hill, Hugh L. Dryden, Jr., Robert Erickson
  • Method and intermediates for producing .alpha.-L-aspartyl-L-phenylalanine
    Patent number: 4555362
    Abstract: This invention encompasses a method and intermediates for preparing a commercial sweetening agent, .alpha.-L-aspartyl-L-phenylalanine methyl ester. The process involves reacting L-aspartic acid with diketene to form N-acetoacetyl-L-aspartic acid which is converted to N-acetoacetyl-L-aspartic anhydride by reaction with acetic anhydride. N-acetoacetyl-L-aspartic anhydride is reacted with L-phenylalanine methyl ester to provide N-acetoacetyl-.alpha.-L-aspartyl-L-phenylalanine methyl ester which is converted to .alpha.-L-aspartyl-L-phenylalanine methyl ester by reaction with hydroxylamine hydrochloride.
    Type: Grant
    Filed: May 15, 1984
    Date of Patent: November 26, 1985
    Assignee: G. D. Searle & Co.
    Inventors: Hugh L. Dryden, Jr, John B. Hill
  • Process for preparing steroidal 3-oxo-4,6-dienes such as 17-hydroxy-3-oxo-17.alpha.-pregna-4,6-diene-21-carboxylic acid.gamma.-lactone
    Patent number: 4155906
    Abstract: A process for preparing 17-hydroxy-3-oxo-17.alpha.-pregna-4,6-diene-21-carboxylic acid .gamma.-lactone by contacting 17-hydroxy-3-oxy-17.alpha.-pregna-3,5-diene-21-carboxylic acid .gamma.-lactone with an appropriate halogenating agent in the presence of an amine base, the corresponding hydrohalide salt thereof, and approximately 1-2 molar equivalents (relative to the lactonic starting material) of water, using a cold solvent as the contact medium, and heating the resultant mixture with a dehydrohalogenating agent, is disclosed.
    Type: Grant
    Filed: December 2, 1977
    Date of Patent: May 22, 1979
    Assignee: G. D. Searle & Co.
    Inventors: Hugh L. Dryden, Jr., Gayle M. Webber
  • Process for the preparation of trimethylsulfoxonium bromide
    Patent number: 4141920
    Abstract: The present invention is concerned with an improved process for the preparation of trimethylsulfoxonium bromide. The improvement in the process comprises the addition of a scavenger to the reaction mixture of dimethyl sulfoxide and methyl bromide.
    Type: Grant
    Filed: September 9, 1977
    Date of Patent: February 27, 1979
    Assignee: G. D. Searle & Co.
    Inventors: Hugh L. Dryden, Jr., Mike G. Scaros, John P. Westrich
  • Process for the preparation of 17.beta.-hydroxy-3-oxo-17.alpha.-pregn-4-ene-21-carboxylic acid .gamma.-lactone
    Patent number: 4057542
    Abstract: A new process for the preparation of 17.beta.-hydroxy-3-oxo-17.alpha.-pregn-4-ene-21-carboxylic acid .gamma.-lactone is described herein. The process makes use of androst-4-ene-3,17-dione as the starting material and 17.alpha.-ethynyl-17.beta.-hydroxyandrost-4-en-3-one as an early intermediate.
    Type: Grant
    Filed: August 30, 1976
    Date of Patent: November 8, 1977
    Assignee: G. D. Searle & Co.
    Inventors: Hugh L. Dryden, Jr., Mike G. Scaros, Thomas J. Telinski
  • Process for the preparation of 17.beta.-hydroxy-3-oxo-17.alpha.-pregn-4-ene-21-carboxylic acid .gamma.-lactone
    Patent number: 4057543
    Abstract: A new process utilizing certain novel intermediates for the preparation of 17.beta.-hydroxy-3-oxo-17.alpha.-pregn-4-ene-21-carboxylic acid .gamma.-lactone is described herein. The procedure utilizes readily available and inexpensive sarsasaponin as starting material.
    Type: Grant
    Filed: July 1, 1976
    Date of Patent: November 8, 1977
    Assignee: G. D. Searle & Co.
    Inventors: Hugh L. Dryden, Jr., Charles S. Markos
  • Process for the conversion of maleic acid derivatives to their corresponding fumaric isomers
    Patent number: H645
    Abstract: A process for the isomerization of maleic acid, its monoesters and monoamides in the presence of thiourea in anhydrous conditions at elevated temperature to the corresponding fumaryl forms yields intermediates which are useful in the synthetic pathways of aspartame and other useful polypeptides.
    Type: Grant
    Filed: July 16, 1987
    Date of Patent: June 6, 1989
    Assignee: The NutraSweet Company
    Inventor: Hugh L. Dryden, Jr.