Patents Assigned to SRM Chemical, Ltd. Co.
  • Patent number: 6137009
    Abstract: The invention is a process to manufacture the intermediate secondary amine N-ethyl-2-chloro-6-fluoro-benzylamine, and then the process of reacting this intermediate to manufacture the herbicide flumetralin. Equimolar quantities of monoethylamine, sodium hydroxide, and 2-chloro-6-fluorobenzyl chloride are reacted at a temperature between about 70.degree. C. and about 100.degree. C. in a composition containing at least 2.5 times the required quantity of monoethylamine. The reagent monoethylamine functions as solvent and heat sink for the reaction, and also minimizes the formation of undesired byproducts. The excess monoethylamine is removed after formation of the intermediate. Then, equimolar quantities of sodium hydroxide in water and molten 4-chloro-3-5-dinitrobenzotrifluoride are added to the intermediate, and the temperature is controlled between about 90.degree. C. and about 115.degree. C. The product of this reaction is relatively pure, i.e., 98 percent by weight, molten flumetralin.
    Type: Grant
    Filed: October 12, 1999
    Date of Patent: October 24, 2000
    Assignee: SRM Chemical, Ltd. Co.
    Inventors: Stefan Kwiatkowski, Steven G. Mobley, Kryzsztof Pupek, Miroslaw Golinski, Paul D. Smith
  • Patent number: 6018079
    Abstract: A simple and inexpensive process is described for reducing the concentration of N-nitroso-containing compounds in compositions comprising N-nitroso-containing compounds and other desired compounds wherein the N-nitroso-containing compounds thermally decompose at a temperature below the decomposition temperature of the desired compounds. For compositions comprising dinitroaniline herbicides wherein the N-nitroso compound is a N-nitroso derivative of a precursor in the manufacture of the herbicide, for example Flumetralin, N-ethyl-N-(2-chloro-6-fluorobenzyl)-2,6-dinitro-4-trifluoromethylaniline, the process requires heating the mixture to a temperature greater than about 120.degree. C., and holding the composition at that temperature for a time effective to decompose the N-nitroso compound present in the mixture. Volatile decomposition products are advantageously removed from the composition.
    Type: Grant
    Filed: May 10, 1999
    Date of Patent: January 25, 2000
    Assignee: SRM Chemical, Ltd, Co.
    Inventors: Lowell J. Lawrence, Stephan Kwiatkowski
  • Patent number: 5922913
    Abstract: Disclosed is a process of nitrating or dinitrating an aromatic amine compound that involves reacting the aromatic amine and nitric acid in the presence of acetic acid such that the molar ratio of the aromatic amine compound to acetic acid is from about 1:2 to about 1:16, and the molar ratio of nitric acid to the aromatic amine is between about 1.0 to about 1.5 times the nitric acid needed to complete the reaction. More particularly, the invention is a process of forming Pendimethalin, N-(1-ethylpropyl)-2,6-dinitro-3,4-xylidine, from N-(1-ethylpropyl)-3,4-xylidine (4-NAX) that involves reacting 4-NAX and nitric acid in the presence of acetic acid such that the molar ratio of nitric to the 4-NAX is between about 2:1 and about 3:1, preferably between about 2:1 and about 2.6:1, and such that the molar ratio of 4-NAX to acetic acid is between about 1:2 to about 1:16, preferably between about 1:4 and about 1:8.
    Type: Grant
    Filed: November 6, 1998
    Date of Patent: July 13, 1999
    Assignee: SRM Chemical, Ltd., Co.
    Inventors: Lowell J. Lawrence, Stefan Kwiatkowski, Paul D. Smith
  • Patent number: 5922915
    Abstract: A simple and inexpensive process is described for reducing the concentration of N-nitroso-containing compounds. The process is applicable for compositions comprising N-nitroso-containing compounds and other desired compounds wherein the N-nitroso-containing compounds thermally decompose at a temperature below the decomposition temperature of the desired compounds. For compositions comprising N-nitroso-pendimethalin in Pendimethalin, the process requires heating the mixture to a temperature greater than about 120.degree. C., and holding the Pendimethalin at that temperature for a time effective to decompose the N-nitroso-pendimethalin present in the mixture. Volatile decomposition products are advantageously removed from the composition.
    Type: Grant
    Filed: May 11, 1998
    Date of Patent: July 13, 1999
    Assignee: SRM Chemical, Ltd., Co.
    Inventors: Lowell J. Lawrence, Stefan Kwiatkowski
  • Patent number: 5777168
    Abstract: This invention relates to a process for producing N-alkyl-dinitroalkylaniline and particularly N-sec-butyl-4-tert-butyl-2,6-dinitroaniline by methylation of an alkylphenol followed by a one or two stage dinitration of the resulting alkylanisole which is followed by reaction with an amine.
    Type: Grant
    Filed: June 3, 1997
    Date of Patent: July 7, 1998
    Assignee: SRM Chemical, Ltd. Co.
    Inventors: Stefan Kwiatkowski, Krzysztof Pupek, Brenda L. Lawrence, Lowell J. Lawrence
  • Patent number: 5770545
    Abstract: This invention relates to pendralin ?2,6-dinitro-N-(1-ethylpropyl)-4-tert-butylaniline!, preemergence and postemergence herbicidal methods and herbicidal compositions employing pendralin.
    Type: Grant
    Filed: March 14, 1997
    Date of Patent: June 23, 1998
    Assignee: SRM Chemical, Ltd. Co.
    Inventors: Lowell J. Lawrence, Terry L. Johnson, Stephan Kwiatkowski, Paul D. Smith
  • Patent number: 5728881
    Abstract: A process is provided for preparing 2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine from 4-chlorotrifluoromethylbenzene. The process includes a two stage nitration and an amination step. Ethylene dichloride is utilized as a diluent and solvent in the nitration steps. Spent acid from the first nitration is reconstituted with sulfur trioxide for use in the second nitration. Spent acid from the second nitration is used directly in the first nitration and evaporation is used to remove nitrosoamines from the final trifluralin product.
    Type: Grant
    Filed: March 5, 1997
    Date of Patent: March 17, 1998
    Assignee: SRM Chemical, Ltd. Co.
    Inventors: Stefan Kwiatkowski, Krzysztof Pupek, Miroslaw J. Golinski, Paul D. Smith, Lowell J. Lawrence
  • Patent number: 5705698
    Abstract: A process is provided for the preparation of isometrically pure pendimethalin and iso-pendimethalin as well as mixtures thereof.
    Type: Grant
    Filed: March 25, 1996
    Date of Patent: January 6, 1998
    Assignee: SRM Chemical, Ltd. Co.
    Inventors: Lowell J. Lawrence, Stefan Kwiatkowski, Krzysztof Pupek, Miroslaw J. Golinski
  • Patent number: 5689006
    Abstract: This invention relates to a process for producing N-alkyl-dinitroalkylaniline and particularly N-sec-butyl-4-tert-butyl-2,6-dinitroaniline by methylation of an alkylphenol followed by nitration of the resulting alkylanisole which is followed by reaction with an amine.
    Type: Grant
    Filed: June 29, 1995
    Date of Patent: November 18, 1997
    Assignee: SRM Chemical, Ltd. Co.
    Inventors: Stefan Kwiatkowski, Krzysztof Pupek, Brenda L. Lawrence, Lowell J. Lawrence
  • Patent number: 5663441
    Abstract: This invention relates to a process for producing mono- and di- N-alkyl-dinitroalkylaniline or dinitroaniline derivative and particularly N-sec-butyl-4-tert-butyl-2,6-dinitroaniline by methylation of an alkylphenol or phenol derivative followed by nitration of the resulting acetic acid alkylanisole or anisole derivative which is followed by reaction with an amine. Acetic acid by-product produced during nitration is recycled by converting back to acetic anhydride.
    Type: Grant
    Filed: March 22, 1996
    Date of Patent: September 2, 1997
    Assignee: SRM Chemical, Ltd. Co.
    Inventors: Stefan Kwiatkowski, Krzysztof Pupek, Brenda L. Lawrence, Lowell J. Lawrence