Title:
PRODUCTION OF 2-METHYL-1,4-NAPHTHOQUINONE
Document Type and Number:
Japanese Patent JP3924732
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain the subject compound in high yield with suppressed formation of by-products in no need of complicated purification procedures after the reaction by oxidizing methylnaphthalene only with dichromic acid with no use of sulfuric acid at all.
SOLUTION: 2-Methylnaphthalene, preferably an aqueous dispersion containing 30-60wt.% of the naphthalene is oxidized by adding an aqueous dichromic acid solution of, preferably 30-60wt.% concentration calculating as anhydrous chromic acid to produce the objective compound. The reaction time is usually 2-5 hours and the produced objective compound is separated by filtration and purified in a usual manner as washing with water. The aqueous solution of dichromic acid is prepared by dissolving chromic acid anhydride (CrO3) in water, but further by adding an inorganic acid to the aqueous solution of a dichromate salt as sodium dichromate to liberate dichromic acid and the resultant aqueous dichromic acid solution can be also utilized. In another case anhydrous chromic acid is recovered after being used in oxidation reaction, and the dichromic acid aqueous solution may be prepared by using the recovered chromic acid anhydride.
Inventors:
Kozo Nakaoji
Shigeru Nakaoji
Shigeru Nakaoji
Application Number:
JP4916497A
Publication Date:
June 06, 2007
Filing Date:
March 04, 1997
Export Citation:
Assignee:
Daiwa Kasei Co., Ltd.
International Classes:
C07C46/04; C07B61/00; C07C50/10; (IPC1-7): C07C50/10; C07C46/04; //C07B61/00
Domestic Patent References:
| JP164092C2 | ||||
| JP166598C2 | ||||
| JP7048309A | ||||
| JP63156740A | ||||
| JP61221148A | ||||
| JP53050147A | ||||
| JP8092152A | ||||
| JP8000997A | ||||
| JP6009485A | ||||
| JP62294638A | ||||
| JP6172254A |
Foreign References:
| US2402226 | ||||
| EP0031573A1 |
Attorney, Agent or Firm:
Eiji Saegusa
Kakehi Yuro
Takeshi Ohara
Hiroji Nakagawa
Yasumitsu Tate
Kenji Saito
Jun Fujii
Hitoshi Seki
Mutsuko Nakano
Kakehi Yuro
Takeshi Ohara
Hiroji Nakagawa
Yasumitsu Tate
Kenji Saito
Jun Fujii
Hitoshi Seki
Mutsuko Nakano