Patents by Inventor Deepak R. Patil

Deepak R. Patil 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: 5696286
    Abstract: A process for the preparation of aromatic substituted carboxylic acids is disclosed. The process comprisesi) forming an aromatic-substituted acrylonitrile by dehydrating a cyanohydrin of the formula ##STR1## where Ar is C.sub.6 to C.sub.10 aryl unsubstituted or substituted with C.sub.1 to C.sub.6 linear or branched alkyl, C.sub.1 to C.sub.6 linear or branched alkoxy, halo, amino, amino mono- or disubstituted with C.sub.1 to C.sub.6 linear or branched alkyl or carboxylic acid or the alkyl esters thereof; and R is hydrogen or C.sub.1 to C.sub.6 linear or branched alkyl;ii) catalytically reducing the aromatic-substituted acrylonitrile when not more than 10% of the cyanohydrin is converted to said acrylonitrile to form a first reaction solution comprising an aromatic substituted aliphatic nitrile;iii) hydrolyzing the aromatic-substituted aliphatic nitrile.
    Type: Grant
    Filed: August 9, 1993
    Date of Patent: December 9, 1997
    Assignee: Albemarle Corporation
    Inventors: Deepak R. Patil, George A. Knesel, Patricia Pringle
  • Patent number: 5574183
    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 diastereomeric salt by reaction comprising said racemic mixture of a C.sub.1 to C.sub.6 linear or branched aliphatic carboxylic acid and an amount of a chiral organic base sufficient to react with one of the enantiomers of the racemic mixture; ii) precipitating from the reaction solution formed in step i) the diastereomeric salt; iii) separating said precipitated diastereomeric salt; iv) decomposing the salt into its enantiomeric component and its organic base component; and v) isolating a substantially pure enantiomer from said decomposed salt.
    Type: Grant
    Filed: January 24, 1995
    Date of Patent: November 12, 1996
    Assignee: Albemarle Corporation
    Inventors: Deepak R. Patil, Venkataraman Ramachandran
  • Patent number: 5260482
    Abstract: A process for obtaining a substantially pure enantiomer of an aryl-substituted aliphatic carboxylic acid is described. The process combines an aryl substituted aliphatic carboxylic acid, a base and water in an inert solvent to make a hydrated salt of the said acid. The process leads to enhanced yield of an enantiomerically enriched hydrated salt of the carboxylic acid.
    Type: Grant
    Filed: October 14, 1992
    Date of Patent: November 9, 1993
    Assignee: Ethyl Corporation
    Inventors: Patricia Pringle, William T. Murray, Douglas K. Thompson, Azfar A. Choudhury, Deepak R. Patil
  • Patent number: 5256816
    Abstract: A process for obtaining a substantially pure enantiomer of an aryl-substituted aliphatic carboxylic acid is described. In this process, the aryl-substituted aliphatic carboxylic acid is reacted with an inorganic base in the presence of an organic base to substantially enrich the precipitate in one of the enantiomers and an improved yield. 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: October 26, 1993
    Assignee: Ethyl Corporation
    Inventors: William T. Murray, Robert E. Young, Azfar A. Choudhury, Deepak R. Patil
  • Patent number: 5235100
    Abstract: A process for the separation of a racemic mixture of certain aliphatic carboxylic acids or esters thereof is disclosed. The process comprises:i) separating a racemic mixture of an aliphatic carboxylic acid or ester thereof having the formula: ##STR1## where R.sub.1 is hydrogen or C.sub.1 to C.sub.6 linear or branched alkyl; R.sub.2, R.sub.3 and R.sub.4 are different and are hydrogen or C.sub.1 to C.sub.6 linear or branched alkyl; cycloalkyl; alkyl-substituted cycloalkyl; C.sub.6 to C.sub.14 aryl; C.sub.1 to C.sub.6 alkylthio; C.sub.2 to C.sub.8 cycloalkylthio; C.sub.6 to C.sub.10 arylthio; C.sub.6 to C.sub.10 arylcarbonyl; C.sub.4 to C.sub.8 cycloalkenyl; trifluoromethyl; halo; or C.sub.4 to C.sub.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: August 10, 1993
    Assignee: Ethyl Corporation
    Inventors: Azfar A. Choudhury, Abbas Kadkhodayan, Deepak R. Patil
  • Patent number: 5235095
    Abstract: An improved process for the separation of enantiomers of a racemic mixture of certain aliphatic carboxylic acids or esters thereof is disclosed. The process involves: (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; and (iii) precipitating from the reaction solution formed in step (ii) the less soluble diastereomeric salt, the improvement being adding to the salt solution of step (ii) an inert organic or inorganic base that is soluble in the salt solution.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: August 10, 1993
    Assignee: Ethyl Corporation
    Inventors: Abbas Kadkhodayan, Deepak R. Patil, Azfar A. Choudhury
  • Patent number: 5235101
    Abstract: An improved process for the separation of enantiomers of a mixture of certain aliphatic carboxylic acids or esters thereof is disclosed. The process involves adding an inert liquid to the reaction solution formed by: (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 less that equimolar equivalents of a chiral organic nitrogenous base; (iii) precipitating from the reaction solution formed in step (ii) the less soluble diastereomeric salt; (iv) addition of a countersolvent to the slurry formed in step (iii); (v) extracting the more soluble diastereomeric salt or the salt of carboxylic acid and the base added in step (i) into the countersolvent. The inert liquid and the countersolvent must be of sufficiently different density.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: August 10, 1993
    Assignee: Ethyl Corporation
    Inventors: Deepak R. Patil, Azfar A. Choudhury, Abbas Kadkhodayan
  • Patent number: 5221765
    Abstract: A method for racemizing an optically active carboxylic acid, or ester thereof, of the formula: ##STR1## where R.sub.1 is hydrogen or C.sub.1 to C.sub.6 linear or branched alkyl; R.sub.2, R.sub.3 and R.sub.4 are different and are hydrogen or C.sub.1 to C.sub.6 linear or branched alkyl, C.sub.1 to C.sub.6 linear or branched haloalkyl, aralkyl, cycloalkyl, alkyl substituted cycloalkyl, C.sub.6 to C.sub.10 aryl, C.sub.1 to C.sub.6 linear or branched alkoxy, C.sub.6 to C.sub.10 aryloxy, C.sub.1 to C.sub.6 alkylthio, C.sub.2 to C.sub.8 cycloalkylthio, C.sub.6 to C.sub.10 arylthio, C.sub.6 to C.sub.10 arylcarbonyl, C.sub.4 to C.sub.8 cycloalkenyl, trifluoromethyl, halo, C.sub.4 to C.sub.5 heteroaryl, C.sub.10 to C.sub.14 aryl, or biphenyl unsubstituted or substituted with methyl or halo, comprising heating said optically active carboxylic acid or ester thereof in the presence of water at a temperature of from about 75.degree. C. to about 200.degree. C.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: June 22, 1993
    Assignee: Ethyl Corporation
    Inventors: Deepak R. Patil, Azfar A. Choudhury, Abbas Kadkhodayan
  • Patent number: 5220053
    Abstract: An improved process for the separation of enantiomers of a racemic mixture of certain aliphatic carboxylic acids or esters thereof is disclosed. The process involves adding a mixture of the aliphatic carboxylic acid to the material formed by: (i) forming a 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 solvent; (ii) treating said solution with a chiral organic nitrogenous base; (iii) precipitating from the reaction solution formed in step (ii) a crystalline material comprised of the less soluble diastereomeric salt. The solution is admixed with the crystalline material for a time sufficient to cause an increase in the amount of the less soluble diastereomeric salt in the crystalline material.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: June 15, 1993
    Assignee: Ethyl Corporation
    Inventors: Azfar A. Choudhury, Abbas Kadkhodayan, Deepak R. Patil
  • Patent number: 4299501
    Abstract: A semicontinuous or continuous process for preparing semisolid dispersions is provided wherein oil and water phases are circulated from a single vessel through a system of mixers and homogenizers until a dispersion is obtained.
    Type: Grant
    Filed: August 10, 1979
    Date of Patent: November 10, 1981
    Assignee: Ortho Pharmaceutical Corporation
    Inventors: Deepak R. Patil, Glenn A. VanBuskirk