Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Patent
1995-11-29
1997-10-07
Davis, Zinna Northington
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C07D21384
Patent
active
056750129
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/JP95/00587 filed Mar. 29, 1995.
TECHNICAL FIELD
The present invention relates to a process for producing a cyanopyridine which is useful, for example, as an intermediate for production of agricultural chemicals or drugs.
BACKGROUND ART
For production of a cyanopyridine, there has been known, for example, a process which comprises reacting nicotinamide with phosphorus Syn., Coll., Vol. IV, p. 166 (1963)!. In this process, however, use of phosphorus pentachloride makes the operation troublesome; the conversion of acid amide group into nitrile group and the chlorination of ring proceed simultaneously, perchlorides are formed, and various side reactions take place; thus, the yield of intended product is not sufficient. Hence, the process has not been satisfactory for selective production of an intended cyanopyridine.
There is also known a process which comprises diazotizing a 3-amino-substituted pyridine derivative and subjecting the diazotization Vol. 487, pp. 127-133 (1931)!. In this process, however, since the reaction proceeds momentarily to generate nitrogen gas explosively, the reaction is difficult to control; the yield of intended product is as low as several %; thus, the process has been insufficient as an industrial process.
The object of the present invention is to solve the problems of the prior art and provide a process for producing, in industry, a cyanopyridine safely and inexpensively with the side reactions being suppressed.
The present inventor made a study hardly in order to achieve the above object. As a result, the present inventor found out that the problems of the prior art can be solved by reacting a particular raw material, i.e. a trichloromethylpyridine having at least one halogen atom substituent at the 2- and 6-positions of the pyridine ring, with an ammonium halide in the presence of an oxide or halide of copper or zinc. A further-continued study has led to the completion of the present invention.
DISCLOSURE OF THE INVENTION
The present invention provides a process for producing a cyanopyridine represented by general formula (3) ##STR3## (wherein R is a hydrogen atom or a halogen atom; X.sup.1 and X.sup.2 are each a hydrogen atom or a halogen atom with a proviso that at least either of X.sup.1 and X.sup.2 is a halogen atom; n is an integer of 1 or 2), which process comprises reacting an ammonium halide with a trichloromethylpyridine represented by general formula (1) ##STR4## (wherein R, X.sup.1, X.sup.2 and n have the same definitions as given above) in the presence of a metal compound represented by general formula (2) oxygen atom; m is an integer of 2 or 1).
BEST MODE FOR CARRYING OUT THE INVNETION
The present invention is hereinafter described in detail.
The trichloromethylpyridine represented by the above-mentioned general formula (1), used in the present invention is a trichloromethylpyridine of general formula (1) wherein the substituents X.sup.1 and X.sup.2 are each a hydrogen atom or a halogen atom including a chlorine atom, a fluorine atom, a bromine atom and an iodine atom (this halogen atom is hereinafter referred to simply as "halogen atom" in some cases) with a proviso that at least either of X.sup.1 and X.sup.2 is a halogen atom; the substituent R is a hydrogen atom or a halogen atom including a chlorine atom, a fluorine atom, a bromine atom and an iodine atom; n is an integer of 1 or 2 and is hereinafter expressed simply as "trichloromethylpyridine (1)" in some cases!. Specific examples of the trichloromethylpyridine are 2-chloro-5-trichloromethylpyridine, 2-chloro-3-trichloromethylpyridine, 2-bromo-5-trichloromethylpyridine, 2-bromo-3-trichloromethylpyridine, 2-fluoro-3-trichloromethylpyridine, 2-fluoro-5-trichloromethylpyridine, 2,3-dichloro-5-trichloromethylpyridine, 2,6-dichloro-3-trichloromethylpyridine, 3-bromo-2-chloro-5-trichloromethylpyridine, 2,6-dibromo-3-trichloromethylpyridine, 2,3,6-trichloro-5-trichloromethylpyridine, 3-bromo-2,6-dichloro-5-trichloromethylpyridine, 2,3,4,6-tetrachloro-5-trichloro-methylpyri
REFERENCES:
Organic Synthesis, vol. 4, p. 166. 1963.
Ann. Chem., vol. 487, pp. 127-133. 1931.
Davis Zinna Northington
Ihara Chemical Industry Co. Ltd.
LandOfFree
Process for production of cyanopyridine 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 production of cyanopyridine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for production of cyanopyridine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2358469