Patents by Inventor Arthur K. Hoffmann

Arthur K. Hoffmann 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: 4620009
    Abstract: A process for the manufacture of 1-(2-alkoxyethyl)-4-phenyl-4-imidazolin-2-ones, 1-(2-alkoxyethyl)-4-phenyl-2-imidazolidones, 1-(2-alkoxyethyl)-4-phenyl-imidazolidine-2-thiones, certain of the corresponding 1-(2-hydroxyethyl) derivatives and their 3-acylated derivatives, and certain related compounds which are all useful as intermediates in a new process for the manufacture of tetramisole, dl-2,3,5,6-tetrahydro-6-phenylimidazo-[2,1-b]thiazole, and its derivatives. The compound tetramisole is useful as an anthelmintic.
    Type: Grant
    Filed: October 1, 1981
    Date of Patent: October 28, 1986
    Assignee: Cyanamid Agricultural de Puerto Rico, Inc.
    Inventors: Sivaraman Raghu, Arthur K. Hoffmann, Balwant Singh
  • Patent number: 4370482
    Abstract: A process for the manufacture of 1-(2-alkoxyethyl)-4-phenyl-4-imidazolin-2-ones, 1-(2-alkoxyethyl)-4-phenyl-2-imidazolidones, 1-(2-alkoxyethyl)-4-phenyl-imidazolidine-2-thiones, certain of the corresponding 1-(2-hydroxyethyl) derivatives, and their 3-acylated derivatives, and certain related compounds which are all useful as intermediates in a new process for the manufacture of the anthelmintic levamisole, (-)-2,3,5,6-tetrahydro-6-phenylimidazo-[2,1-b]thiazols, and its derivatives through conventional resolution procedures. The new process also permits the direct manufacture of optically active 1-(2-alkoxyethyl)-4-phenyl-2-imidazolidone and their 3-acylated derivatives, optically active 1-(2-alkoxyethyl)-4-phenylimidazolidine-2-thiones, and levamisole, the levorotatory isomer of tetramisole, using catalytic amounts of a chiral reducing agent, with the elimination of conventional resolution procedures.
    Type: Grant
    Filed: October 28, 1981
    Date of Patent: January 25, 1983
    Assignee: American Cyanamid Co.
    Inventors: Sivaraman Raghu, Arthur K. Hoffmann, Balwant Singh
  • Patent number: 4314066
    Abstract: A process for the manufacture of 1-(2-alkoxyethyl)-4-phenyl-4-imidazolin-2-ones, 1-(2-alkoxyethyl)-4-phenyl-2-imidazolidones, 1-(2-alkoxyethyl)-4-phenyl-imidazolidine-2-thiones, certain of the corresponding 1-(2-hydroxyethyl) derivatives, and their 3-acylated derivatives, and certain related compounds which are all useful as intermediates in a new process for the manufacture of the anthelmintic levamisole, (-)-2,3,5,6-tetrahydro-6-phenylimidazo-[2,1-b]thiazole, and its derivatives through conventional resolution procedures. The new process also permits the direct manufacture of optically active 1-(2-alkoxyethyl)-4-phenyl-2-imidazolidone and their 3-acylated derivatives, optically active 1-(2-alkoxyethyl)-4-phenylimidazolidine-2-thiones, and levamisole, the levorotatory isomer of tetramisole, using catalytic amounts of a chiral reducing agent, with the elimination of conventional resolution procedures.
    Type: Grant
    Filed: February 15, 1978
    Date of Patent: February 2, 1982
    Assignee: American Cyanamid Co.
    Inventors: Sivaraman Raghu, Arthur K. Hoffmann, Balwant Singh
  • Patent number: 4310672
    Abstract: A process for the manufacture of 1-(2-alkoxyethyl)-4-phenyl-4-imidazolin-2-ones, 1-(2-alkoxyethyl)-4-phenyl-2-imidazolidones, 1-(2-alkoxyethyl)-4-phenyl-imidazolidine-2-thiones, certain of the corresponding 1-(2-hydroxyethyl) derivatives and their 3-acylated derivatives, and certain related compounds which are all useful as intermediates in a new process for the manufacture of tetramisole, di-2,3,5,6-tetrahydro-6-phenylimidazo-[2,1-b]thiazole, and its derivatives. The compound tetramisole is useful as an anthelmintic.
    Type: Grant
    Filed: March 17, 1980
    Date of Patent: January 12, 1982
    Assignee: American Cyanamid Co.
    Inventors: Sivaraman Raghu, Arthur K. Hoffmann, Balwant Singh
  • Patent number: 4273764
    Abstract: Resmethrin and 4,5-benzospiro[2,4]hepta-4,6-diene-1-carboxylic acid, .alpha.-cyano-m-phenoxybenzyl ester are stabilized against degradation with stabilizing amounts of nickel complexes of 2,2'-thiobis(p-alkylphenols).
    Type: Grant
    Filed: August 30, 1979
    Date of Patent: June 16, 1981
    Assignee: American Cyanamid Company
    Inventors: Arnold Zweig, Arthur K. Hoffmann
  • Patent number: 4210760
    Abstract: Dehydrogenation processes comprising contacting 1-(2-alkoxyalkyl)-4-aryl-2-imidazolidone with catalysts comprising a noble metal adsorbed on a carrier to produce 1-(2-alkoxyalkyl)-4-aryl-4-imidazolin-2-ones, the dehydrogenation products being useful for synthesis with prochiral catalysts to provide enantiomerically enhanced imidazolidones.
    Type: Grant
    Filed: November 6, 1978
    Date of Patent: July 1, 1980
    Assignee: American Cyanamid Company
    Inventors: Sivaraman Raghu, Arthur K. Hoffmann
  • Patent number: 4139707
    Abstract: A process for the manufacture of 1-(2-alkoxyethyl)-4-phenyl-4-imidazolin-2-ones, 1-(2-alkoxyethyl)-4-phenyl-2-imidazolidones, 1-(2-alkoxyethyl)-4-phenyl-imidazolidine-2-thiones, certain of the corresponding 1-(2-hydroxyethyl) derivatives and their 3-acylated derivatives, and certain related compounds which are all useful as intermediates in a new process for the manufacture of tetramisole, dl-2,3,5,6-tetrahydro-6-phenylimidazo-[2,1-b]thiazole, and its derivatives. The compound tetramisole is useful as an anthelmintic.
    Type: Grant
    Filed: March 8, 1978
    Date of Patent: February 13, 1979
    Assignee: American Cyanamid Company
    Inventors: Sivaraman Raghu, Arthur K. Hoffmann, Balwant Singh