Patents by Inventor Thanikavelu Manimaran

Thanikavelu Manimaran 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).

  • Patent number: 5304524
    Abstract: A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
    Type: Grant
    Filed: October 8, 1992
    Date of Patent: April 19, 1994
    Assignee: Ethyl Corporation
    Inventors: W. Dirk Klobucar, Charles H. Kolich, Thanikavelu Manimaran, Tse-Chong Wu
  • Patent number: 5302263
    Abstract: A process for obtaining an aryl-substituted aliphatic nitrile is described. The process utilizes a solution of an aryl-substituted aliphatic halide and an organic or inorganic cyanide substantially insoluble in the solution. The mixture is subjected to ultrasonic vibrations for a time and at a temperature sufficient to produce the aryl-substituted aliphatic nitrile.
    Type: Grant
    Filed: April 29, 1993
    Date of Patent: April 12, 1994
    Assignee: Ethyl Corporation
    Inventor: Thanikavelu Manimaran
  • Patent number: 5302751
    Abstract: A process is disclosed that is useful for separating the enantiomers of a racemic mixture of an aliphatic carboxylic acid having the formula ##STR1## where R.sub.1 is hydrogen or alkyl, R.sub.2, R.sub.3 and R.sub.4 are independently different and are hydrogen, alkyl, cycloalkyl, alkenyl, alkynyl, phenyl, substituted phenyl, naphthyl, substituted naphthyl, heteroaryl, substituted heteroaryl, haloalkyl, alkoxyalkyl, alkylthioalkyl, phenylalkyl, substituted phenylalkyl, heteroalkylalkyl, substituted heteroalkylalkyl or cycloalkylalkyl.
    Type: Grant
    Filed: January 21, 1992
    Date of Patent: April 12, 1994
    Assignee: Ethyl Corporation
    Inventors: Thanikavelu Manimaran, Alicia A. Potter
  • Patent number: 5278337
    Abstract: A process for obtaining a substantially pure enantiomer of an aryl-substituted aliphatic carboxylic acid is described. The process utilizes first an enantiomerically enriched mixture the of aryl-substituted aliphatic carboxylic acid obtained from kinetic resolution, diastereomeric crystallization or asymmetric synthesis processes. This enriched mixture is reacted with a base producing a salt that has the following properties:1) has at least one eutectic point;2) a composition that is not at the eutectic point; and3) a eutectic composition that is closer to the racemic composition than is the eutectic composition of said aryl-substituted carboxylic acid.Substantially pure, enantiomeric salt is separated, leaving a mother liquor comprising the solvent and aryl-substituted aliphatic carboxylic acid enriched in the other enantiomer.
    Type: Grant
    Filed: October 14, 1992
    Date of Patent: January 11, 1994
    Assignee: Ethyl Corporation
    Inventors: Thanikavelu Manimaran, G. Patrick Stahly, R. Carl Herndon, Jr.
  • Patent number: 5248813
    Abstract: A process for obtaining a substantially pure enantiomer of an aryl-substituted aliphatic carboxylic acid is described. The process utilizes first an enantiomerically enriched mixture the of aryl-substituted aliphatic carboxylic acid obtained from kinetic resolution, diastereomeric crystallization or asymmetric synthesis processes. This enriched mixture is reacted with a base producing a salt that has the following properties:(1) has at least one eutectic point;(2) a composition that is not at the eutectic point; and(3) a eutectic composition that is closer to the racemic composition than is the eutectic composition of said aryl-substituted carboxylic acid.Substantially pure, enantiomeric salt is separated, leaving a mother liquor comprising the solvent and aryl-substituted aliphatic carboxylic acid enriched in the other enantiomer.
    Type: Grant
    Filed: October 14, 1992
    Date of Patent: September 28, 1993
    Assignee: Ethyl Corporation
    Inventors: Thanikavelu Manimaran, G. Patrick Stahly, R. Carl Herndon, Jr.
  • Patent number: 5202472
    Abstract: A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: April 13, 1993
    Assignee: Ethyl Corporation
    Inventors: Thanikavelu Manimaran, W. Dirk Klobucar, Charles H. Kolich
  • Patent number: 5190905
    Abstract: A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: March 2, 1993
    Assignee: Ethyl Corporation
    Inventors: Charles H. Kolich, Thanikavelu Manimaran, W. Dirk Klobucar
  • Patent number: 5191095
    Abstract: A process for the asymmetric reduction of olefinic amides of the formula ##STR1## where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: March 2, 1993
    Assignee: Ethyl Corporation
    Inventors: Thanikavelu Manimaran, W. Dirk Klobucar, Charles H. Kolich
  • Patent number: 5187281
    Abstract: A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: February 16, 1993
    Assignee: Ethyl Corporation
    Inventors: Charles H. Kolich, Thanikavelu Manimaran, W. Dirk Klobucar
  • Patent number: 5187135
    Abstract: A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: February 16, 1993
    Assignee: Ethyl Corporation
    Inventors: Charles H. Kolich, Thanikavelu Manimaran, W. Dirk Klobucar
  • Patent number: 5187136
    Abstract: A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: February 16, 1993
    Assignee: Ethyl Corporation
    Inventors: W. Dirk Klobucar, Charles H. Kolich, Thanikavelu Manimaran
  • Patent number: 5177231
    Abstract: A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: January 5, 1993
    Assignee: Ethyl Corporation
    Inventors: Thanikavelu Manimaran, W. Dirk Klobucar, Charles H. Kolich
  • Patent number: 5162576
    Abstract: A method for resolving (.+-.)-(.alpha.)-(3-benzoylphenyl) propionic acid is disclosed. The method comprises:i) converting said propionic acid with (-)-cinchonidine in a solvent comprising a mixture of an aliphatic ester and an alkyl alcohol;ii) separating teh diastereomeric salt from such conversion;iii) purifying said separated diastereomeric salt by a single recrystallization; andiv) isolating highly pure (+)-.alpha.-(3-benzoylphenyl) propionic acid without any further recrystallization.
    Type: Grant
    Filed: April 15, 1991
    Date of Patent: November 10, 1992
    Assignee: Ethyl Corporation
    Inventors: Thanikavelu Manimaran, Alicia A. Potter
  • Patent number: 5015764
    Abstract: A process for the separation of a racemic mixture of certain aliphatic carboxylic acids or esters thereof is disclosed. The process comprises (i) forming a salt solution comprising said racemic mixture of a C.sub.1 to C.sub.6 linear or branched aliphatic carboxylic acid and an organic or inorganic base (ii) treating said salt solution with one-half molar equivalent of a chiral organic nitrogenous base having a base strength no stronger than said organic or inorganic base (iii) precipitating from the reaction solution formed in step (ii) the less soluble diastereomeric salt and (iv) separating said precipitated diastereomeric salt.
    Type: Grant
    Filed: June 18, 1990
    Date of Patent: May 14, 1991
    Assignee: Ethyl Corporation
    Inventors: Thanikavelu Manimaran, Fred J. Impastato
  • Patent number: 4968837
    Abstract: Racemic 2-(N-propylamino)-5-methoxytetralin is resolved by treating it with a chiral diaroyltartaric acid in an organic solvent at an elevated temperature to form a salt of the amine and chiral diaroyltartaric acid which is soluble in the solvent at the elevated temperature, cooling to precipitate the salt, isolating it, and converting it to the free amine. The product is useful as an intermediate in the synthesis of optionally-active pharmaceutical, such as N-0437.
    Type: Grant
    Filed: July 28, 1989
    Date of Patent: November 6, 1990
    Assignee: Ethyl Corporation
    Inventors: Thanikavelu Manimaran, Fred J. Impastato