Patents by Inventor Koichi Ishii

Koichi Ishii 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).

  • Method relating to manufacture of coumarin derivatives
    Patent number: 3933847
    Abstract: A coumarin dye of the formula (Ia), ##SPC1##Wherein R.sub.1 is hydrogen, chlorine or C.sub.1 -C.sub.2 alkyl, R.sub.2 and R.sub.3 are hydrogen or C.sub.1 -C.sub.4 alkyl, or a quarternary salt thereof having the formula (Ib), ##SPC2##Wherein R.sub.1, R.sub.2 and R.sub.3 are as defined above, R.sub.4 is C.sub.1 -C.sub.2 alkyl or benzyl, and X.sup.- is an anion, is prepared by an improved method, which comprises reacting a diamine of the formula, ##SPC3##Wherein R.sub.1 is as defined above, with a compound of the formula,X -- CH.sub.2 -- Ywherein X and Y are the same or different and are carboxyl, carbamoyl, alkoxycarbonyl or cyano, in 10 to 70 % sulfuric acid to prepare an imidazolyl acetic acid of the formula, ##SPC4##Wherein R.sub.1 is as defined above, and then reacting the imidazolyl acetic acid with a compound of the formula, ##SPC5##Wherein R.sub.2 and R.sub.3 are as defined above, to obtain the dye (Ia), or further reacting the resulting dye (Ia) with an alkylating agent to obtain the dye (Ib).
    Type: Grant
    Filed: December 19, 1973
    Date of Patent: January 20, 1976
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Masaaki Ohkawa, Koichi Ishii