Patents Assigned to Cheng Hong Chemical Co., Ltd.
  • Process for preparing 1,1'-dialkyl-4,4'-bipyridylium dihalide
    Patent number: 4223150
    Abstract: 1,1' dialkyl -4,4'-bipyridylium dihalide is prepared by heating 4,4'-bipyridyl with an .alpha.-halogen substituted organic acid of formula X R.sub.1 COOH where X is Cl or Br, R is C.sub.1-3, preferably monochloroacetic acid alkyl group in the presence of water until the pH is below 4.0.
    Type: Grant
    Filed: October 10, 1978
    Date of Patent: September 16, 1980
    Assignee: Cheng Hong Chemical Co., Ltd.
    Inventor: Ming F. Chen