Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Patent
1992-09-25
1994-04-05
Rotman, Alan L.
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C07D21361
Patent
active
053006500
DESCRIPTION:
BRIEF SUMMARY
INDUSTRIAL FIELD OF UTILIZATION
The present invention relates to a process for producing an aminomethylpyridine having a chlorine atom at the .alpha.-position. The aminomethylpyridine having a chlorine atom at the .alpha.-position is a compound which is useful as a raw material for synthesis of medicines, agricultural chemicals, etc.
PRIOR ART
For production of an aminomethylpyridine having a chlorine atom at the .alpha.-position, there has example, 2-chloro-5-cyanopyridine to a catalytic reduction using a Raney nickel in the presence of ammonia, water and, as necessary, an organic solvent to produce 2-chloro-5-aminomethylpyridine (DT Laid-Open Publication No. 3726933).
PROBLEMS TO BE SOLVED BY THE INVENTION
In the above conventional process, however, the yield of desired product is about 50% as shown in Comparative Example described later, and is not sufficiently high; thus, said process is not satisfactory as an industrial process.
The object of the present invention is to provide a process for producing an aminomethylpyridine having a chlorine atom at the .alpha.-position, at a high yield as compared with the conventional processes.
MEANS FOR SOLVING THE PROBLEMS
In order to improve the conventional processes, the present inventor paid attention to aminomethylpyridine which is produced in a large amount as a by-product in said process (reference can be made to Comparative Example described later). In view of the fact that a chlorine atom bonding to the .alpha.-position of pyridine nucleus is very active generally, the present inventor assumed that the above aminomethylpyridine as by-product is formed as a result of removal of a chlorine atom at the .alpha.-position under the catalytic reduction conditions employed.
Hence, the present inventor made research on a method capable of depressing the reaction for the above removal of chlorine atom (dechlorination). As a result, it was surprisingly found the fact that the removal of a chlorine atom at the .alpha.-position and other side reactions are depressed by subjecting a starting material, i.e., a cyanopyridine having a chlorine atom at the .alpha.-position, to a catalytic reduction in the presence of a hydrogenation catalyst in a non-aqueous reaction system and thereby the yield of desired product, i.e., an aminomethylpyridine having a chlorine atom at the .alpha.-position can be increased. The finding has led to the completion of the present invention.
The present inventor made further study. As a result, it was found the fact that the removal of a chlorine atom at the .alpha.-position atom and other side reactions are depressed more preferably by subjecting a cyanopyridine having a chlorine atom at the .alpha.-position, to a catalytic reduction with a tertiary amine being allowed to coexist in the reaction system and thereby the yield of a desired product, i.e., an aminomethylpyridine having a chlorine atom at the .alpha.-position can be increased further. The finding has led to the completion of the present invention.
The present invention relates to a process for producing an aminomethylpyridine having a chlorine atom at the .alpha.-position in the pyridine nucleus by subjecting a starting material, i.e., a cyanopyridine having a chlorine atom at the .alpha.-position, to a catalytic reduction in the presence of a hydrogenation catalyst, which process is characterized in that said cyanopyridine is subjected to a catalytic reduction in an non-aqueous reaction system, as well as to a process for producing an aminomethylpyridine having a chlorine atom at the .alpha.-position in the pyridine nucleus by subjecting a cyanopyridine having a chlorine atom at the .alpha.-position, to a catalytic reduction in the presence of a hydrogenation catalyst, which process is characterized in that said cyanopyridine is subjected to a catalytic reduction with a tertiary amine being allowed to coexist in the reaction system.
As to the cyanopyridine having a chlorine atom at the .alpha.-position, used as a starting material in the Present invention, there are ment
Davis Zinna N.
Koei Chemical Co. Ltd.
Rotman Alan L.
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