Organic compounds -- part of the class 532-570 series – Organic compounds – Four or more ring nitrogens in the bicyclo ring system
Patent
1995-10-05
1998-04-14
Bernhardt, Emily
Organic compounds -- part of the class 532-570 series
Organic compounds
Four or more ring nitrogens in the bicyclo ring system
544235, C07D23704
Patent
active
057393290
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a process for producing a hexahydropyridazine which is useful as an intermediate for benzothiazine type agricultural chemicals (herbicide), and to a process for producing a hexahydropyridazine-1,2-dicarboxy derivative which is useful as an intermediate for producing this hexahydropyridazine.
BACKGROUND ART
The production of hexahydropyridazine has heretofore been carried out by isolating a hexahydropyridazine-1,2-dicarboxy derivative and then decarboxylating the same; however, no process for producing hexahydropyridazine by decarboxylating the hexahydropyridazine-1,2-dicarboxy derivative without isolation has been known.
As a process for producing the above hexahydropyridazine-1,2-dicarboxy derivative, the present inventors have already proposed a process by which a hydrazinedicarboxy derivative represented by the general formula: 1,4-dihalogenobutane in the presence of a base selected from alkali metal carbonates and hydroxides (see Japanese Patent Application Kokai No. 4-244,067).
However, this process has been unable to obtain the objective compound in a sufficient yield in the case where an alkali metal hydroxide is used as the base for a compound having the above formula for hydrazinedicarboxy derivative in which R represents an alkoxy group.
An object of the present invention is to provide a process for producing hexahydropyridazine simply and cheaply on an industrial scale.
Another object of the present invention is to provide a process for producing a hexahydropyridazine-1,2-dicarboxy derivative which process has solved the above-mentioned problems of prior art.
The present inventor has made extensive research for the purpose of providing a process for producing a hexahydropyridazine-1,2-dicarboxy derivative by which the above-mentioned problems of prior art have been solved, and has, as a result, found that when in a process for producing a hexahydropyridazine-1,2-dicarboxy derivative by reacting a hydrazinedicarboxy derivative with a dihalogenobutane in the presence of an alkali metal hydroxide, said reaction is conducted in an aprotic polar solvent, the problems of prior art can be solved, and further found that the hexahydropyridazine is obtained by such a simple procedure that the thus obtained hexahydropyridazine-1,2-dicarboxy derivative is decarboxylated without isolation using an alkali metal hydroxide. Based on this findings, he has completed the present invention directed to a process for producing hexahydropyridazine simply and cheaply on an industrial scale.
DISCLOSURE OF THE INVENTION
That is to say, the first process of the present invention provides a process for producing a hexahydropyridazine-1,2-dicarboxy derivative represented by the general formula: ##STR2## wherein R.sup.1 and R.sup.2 represent each independently an alkyl group, by reacting a hydrazinedicarboxy derivative represented by the general formula: dihalogenobutane represented by the general formula: the presence of an alkali metal hydroxide, characterized in that above reaction is effected in an aprotic polar solvent.
The second process of the present invention provides a process for producing hexahydropyridazine, characterized by reacting a hydrazinedicarboxy derivative represented by the general formula: with a dihalogenobutane represented by the general formula: the presence of an alkali metal hydroxide in an aprotic polar solvent to obtain a hexahydropyridazine-1,2-dicarboxy derivative represented by the general formula: ##STR3## wherein R.sup.1 and R.sup.2 have the same meaning as above, and decarboxylating this hexahydropyridazine-1,2-dicarboxy derivative without isolation in the presence of an alkali metal hydroxide and a hydrogen-donating compound.
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention is explained in detail below.
In the present invention, first of all, according to the first process of the present invention, the hydrazinedicarboxy derivative (1) is reacted with the dihalogenobutane (2) in the presence of an alkali metal hydro
REFERENCES:
patent: 2841584 (1958-07-01), Hunter
patent: 5310738 (1994-05-01), Nakayama
Abstract for JP 4-244067 (Sep. 1, 1992), Nakayama.
English translation of JP 40785 (Apr. 1978).
Bernhardt Emily
Ihara Chemical Industry Co. Ltd.
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