Patents by Inventor Linhua Wang

Linhua Wang 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: 6664422
    Abstract: The present invention relates to a novel improved process and intermediates for the process of preparing the oxime intermediates of formula (II) wherein R1 is hydrogen, fluoro or chloro, and R2 is methyl, ethyl, methoxy, ethoxy, trifluoromethyl, trifluoromethoxy, cyano, fluoro, chloro or bromo. The novel process comprises diazotizing an aniline of formula (VI) reacting the resulting diazonium salt with isopropenylacetate of formula (X) and reacting the resulting ketone of formula (XI) with an organic nitrite in the presence of hydrogene chloride, and methylating the resulting ketooxime of formula (VIII) with a methylating agent and reacting the resulting O-methyl ketooxime of formula (IX) with hydroxylamine. The compounds of formula (II) are intermediates for highly active fungicides from the class of the strobilurins.
    Type: Grant
    Filed: August 13, 2001
    Date of Patent: December 16, 2003
    Assignee: Bayer Aktiengesellschaft
    Inventors: Rudolf Waditschatka, René Zurflüh, Edward Kelsall, Hugo Ziegler, Linhua Wang
  • Patent number: 6211413
    Abstract: There is provided a process for the preparation of compounds of formula I wherein: X is H or F, Y is CF3 or F and R1 is hydrogen or C1-C2alkyl; in which process (1) a compound of formula II, wherein X and Y are as defined for formula I, is reacted with an organic or inorganic nitrite or nitrous acid; (2) the resulting diazonium compound of formula III is reacted with an aldoxime of formula V R1—CH═NOH   (V) wherein R1 is as defined for formula I, in presence of CuSO4; and (3) the resulting oxime of formula IV is hydrolyzed with aqueous acid to the compound of formula I.
    Type: Grant
    Filed: January 12, 1999
    Date of Patent: April 3, 2001
    Assignee: Bayer Aktiengesellschaft
    Inventors: Arthur Wegmann, Terry Lee Moore, Linhua Wang