Process for producing 2,6-dihydroxy-3,4-dialkylpyridines

Details Process for producing 2,6-dihydroxy-3,4-dialkylpyridines Process for producing 2,6-dihydroxy-3,4-dialkylpyridines

2002-03-28

2003-09-23

Desai, Rita (Department: 1751)

Organic compounds -- part of the class 532-570 series

Organic compounds

Heterocyclic carbon compounds containing a hetero ring...

C546S290000

Reexamination Certificate

active

06624307

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to a composition for the oxidation dyeing of keratin fibers, in particular human keratin fibers such as hair. More particularly, it relates to pyridine derivatives made by a novel process, which derivatives are used in such composition.
2. Reported Developments
The preferred compound of the present invention, 2,6-dihydroxy-3,4-dimethylpyridine, is known and has been reported by H. Rogerson and J. F. Thorpe,
J. Chem. Soc
., (1905) 87, 1685 and J. P. Wibaut and E. C. Kooyman,
Rec. Trav. Chim
. (1944), 63, 231. Years later, the compound and its use in hair-dyeing composition was reported in U.S. Pat. Nos. 4,838,893, 4,900,325 and 5,769,903. The above-quoted patents do not appear to describe the synthesis of 2,6-dihydroxy-3,4-diakylpyridine which, by the literature references, appears to be economically unattractive.
SUMMARY OF THE INVENTION
Compounds of substituted 2,6-dihydroxy-3,4-dialkylpyridine are prepared by the following synthetic method shown in Scheme A:
wherein
R
1
is H, C
1
-C
4
alkyl or aryl;
R
2
is H, C
1
-C
4
alkyl or aryl;
R
3
is methyl, ethyl, t-butyl;
R
3
is H, CN, CONH
2
;
M is an alkali metal, preferably Na or K;
R is methyl, ethyl or tert-butyl; and
Alcohol is methanol, ethanol, isopropanol, propanol, butanols or pentanols.
The preferred compound produced by the method of the present invention is 2,6-dihydroxy-3,4-dimethylpyridine is shown in Scheme B:


REFERENCES:
patent: 4745652 (1988-05-01), Rose et al.
patent: 4838893 (1989-06-01), Rose et al.
patent: 4900325 (1990-02-01), Rose et al.
patent: 5769903 (1998-06-01), Audousset et al.
patent: 6074438 (2000-06-01), Lim et al.
Kenner C. Rice in the Synthesis and Analgesic . . . Journal of Medicinal Chemistry 1975, vol 18 No. 8.*
James Kutney et in Synthesis in Pyridine Series 1961.*
J.B. Wibout and E.C. Kooyman, Synthesis of 3,4-Dimethylpyridie, 2,3-Dimethylpyridine and 2-Methyl-3-Ethylpyridine,Rec. Trav. Chim., vol. 63, p. 231 (1944).
Rogerson and Thorpe, “Some Alkyl Derivatives of Glutaconic Acid and 2:6-Dihydroxypyridine”,Journal of the Chemical Society, vol. 87, pp. 1685 (1905).

Affiliated with

Also associated with

Rating

Process for producing 2,6-dihydroxy-3,4-dialkylpyridines does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process for producing 2,6-dihydroxy-3,4-dialkylpyridines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for producing 2,6-dihydroxy-3,4-dialkylpyridines will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3014633