Patents by Inventor Brian K. M. Cheng

Brian K. M. Cheng 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: 5633407
    Abstract: A process for preparing substituted aromatic azo compounds is provided which comprises contacting a nucleophilic compound and an azo containing compound in the presence of a suitable solvent system, and reacting the nucleophilic compound and the azo containing compound in the presence of a suitable base and a controlled amount of protic material at a temperature of about 10.degree. C. to about 150.degree. C. in a confined reaction zone wherein the molar ratio of protic material to base is 0:1 to about 5:1. In another embodiment, the substituted aromatic azo compounds are further reacted with a nucleophilic compound in the presence of a suitable solvent system, a suitable base and a controlled amount of protic material at a temperature of about 70.degree. C. to about 200.degree. C. in a confined reaction zone wherein the molar ratio of protic material to base is 0:1 to about 5:1 to produce a substituted aromatic amine.
    Type: Grant
    Filed: May 18, 1995
    Date of Patent: May 27, 1997
    Assignee: Flexsys America L. P.
    Inventors: Michael K. Stern, Brian K-M Cheng
  • Patent number: 5618979
    Abstract: A process for preparing substituted aromatic amines which comprises contacting a nucleophilic compound and a substituted aromatic azo compound in the presence of a suitable solvent system, and reacting the nucleophilic compound and the substituted aromatic azo compound in the presence of a suitable base and a controlled amount of protic material at a temperature of about 70.degree. C. to about 200.degree. C. in a confined reaction zone wherein the molar ratio of protic material to base is 0:1 to about 5:1. In another embodiment, the substituted aromatic amines of the invention are reductively alkylated to produce alkylated diamines or substituted derivatives thereof.
    Type: Grant
    Filed: May 18, 1995
    Date of Patent: April 8, 1997
    Assignee: Flexsys America L. P.
    Inventors: Michael K. Stern, Brian K-M Cheng
  • Patent number: 5552531
    Abstract: A process for preparing substituted aromatic azo compounds is provided which comprises contacting a nucleophilic compound and an azo containing compound in the presence of a suitable solvent system, and reacting the nucleophilic compound and the azo containing compound in the presence of a suitable base and a controlled amount of protic material at a temperature of about 10.degree. C. to about 150.degree. C. in a confined reaction zone wherein the molar ratio of protic material to base is 0:1 to about 5:1.
    Type: Grant
    Filed: April 6, 1993
    Date of Patent: September 3, 1996
    Assignee: Monsanto Company
    Inventors: Michael K. Stern, Brian K.-M. Cheng
  • Patent number: 5451702
    Abstract: A process for preparing substituted aromatic amines is provided which comprises contacting a nucleophilic compound and an azo containing compound in the presence of a suitable solvent system, reacting the nucleophilic compound and the azo containing compound in the presence of a suitable base and a controlled amount of protic material at a temperature of about 10.degree. C. to about 150.degree. C. in a confined reaction zone wherein the molar ratio of protic material to base is 0:1 to about 5:1 and reducing the product of the reaction of the nucleophilic compound and the azo containing compound under conditions which produce the substituted aromatic amine. In another embodiment, the substituted aromatic amines of the invention are reductively alkylated to produce alkylated diamines or substituted derivatives thereof.
    Type: Grant
    Filed: April 26, 1993
    Date of Patent: September 19, 1995
    Assignee: Monsanto Company
    Inventors: Michael K. Stern, Brian K-M Cheng
  • Patent number: 5382691
    Abstract: A process for preparing substituted aromatic amines is provided which comprises contacting a substituted aromatic azo compound and an alcohol selected from the group consisting of aliphatic alcohols, cycloaliphatic alcohols, arylalkyl alcohols and mixtures thereof in the presence of a suitable base at a temperature of about 70.degree. C. to about 200.degree. C. In another embodiment, the substituted aromatic amines of the invention are reductively alkylated to produce alkylated diamines or substituted derivatives thereof.
    Type: Grant
    Filed: November 5, 1993
    Date of Patent: January 17, 1995
    Assignee: Monsanto Company
    Inventors: Michael K. Stern, Brian K-M. Cheng
  • Patent number: 5380946
    Abstract: A process for preparing p-nitroaromatic amides is provided which comprises contacting a nitrile, nitrobenzene, a suitable base and water in the presence of a suitable solvent system to form a mixture, and reacting the mixture at a suitable temperature in a confined reaction zone in the presence of a controlled amount of protic material. The p-nitroaromatic amides of the invention can be reduced to p-aminoaromatic amides. In one embodiment, the p-aminoaromatic amide is further reacted with ammonia under conditions which produce the corresponding p-aminoaromatic amine and the amide corresponding to the nitrile starting material or with water in the presence of a suitable basic or acidic catalyst under conditions which produce the corresponding p-aminoaromatic amine and the acid or salt thereof corresponding to the nitrile starting material. In another embodiment, the p-aminoaromatic amine is reductively alkylated to produce alkylated p-aminoaromatic amine.
    Type: Grant
    Filed: July 30, 1993
    Date of Patent: January 10, 1995
    Assignee: Monsanto Company
    Inventors: Michael K. Stern, Brian K. M. Cheng