Process for producing substituted arylpyrazoles

Details Process for producing substituted arylpyrazoles Process for producing substituted arylpyrazoles

1998-11-05

2000-05-09

Ramsuer, Robert W.

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

Organic compounds

Heterocyclic carbon compounds containing a hetero ring...

C07D23112

Patent

active

060606053

DESCRIPTION:

BRIEF SUMMARY
TECHNICAL FIELD OF THE INVENTION

The invention relates to a novel process and novel intermediates for preparing substituted arylpyrazoles which are known as intermediates for herbicides.


BACKGROUND OF THE INVENTION

A number of processes for preparing herbicidally active arylpyrazoles have already been disclosed; however, these processes afford the desired products in not quite satisfactory yields (cf. U.S. Pat. No. 5,281,571).


DETAILED DESCRIPTION OF THE INVENTION

This invention, accordingly, provides a novel process for preparing substituted arylpyrazoles of the general formula (I) ##STR2## in which R.sup.1 represents hydrogen or halogen, (II) ##STR3## in which R.sup.1, R.sup.2 and R.sup.3 are each as defined above and ##STR4## in which Z represents 1-hydroxy-isopropyl or trimethylsilyl, appropriate in the presence of a diluent, at temperatures between 50.degree. C. and 150.degree. C., the substituted arylalkines formed of the general formula (IV) ##STR5## in which R.sup.1, R.sup.2, R.sup.3 and Z are each as defined above hydroxide and/or an alkali metal fluoride or alkaline earth metal fluoride, if appropriate in the presence of a reaction auxiliary and if appropriate in the presence of a diluent, at temperatures between 50.degree. C. and 150.degree. C., the arylalkines formed of the general formula (V) ##STR6## in which R.sup.1, R.sup.2 and R.sup.3 are each as defined above (VI) appropriate in the presence of a diluent, at temperatures between 0.degree. C. and 150.degree. C., and the arylalkinones formed of the general formula (VII) ##STR7## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each as defined above the presence of a diluent, at temperatures between 0.degree. C. and 150.degree. C.
Surprisingly, the substituted arylpyrazoles of the general formula (I) can be obtained in very high yields and in very good quality by the process according to the invention.
The process according to the invention thus represents a useful advance on the prior art.
The process according to the invention preferably relates to the preparation of compounds of the formula (I) in which -halogenoalkyl or C.sub.1 -C.sub.6 -alkoxy-carbonyl and -C.sub.6 -alkyl.
The process according to the invention in particular relates to the preparation of compounds of the formula (I) in which methoxycarbonyl or ethoxycarbonyl and each of which is optionally substituted by fluorine and/or chlorine.
Using, for example, in the first step 4-bromo-3-fluoro-2-methyl-benzonitrile and 2-methyl-3-butin-2-ol as starting materials, reacting in the next stage with sodium hydroxide and then further with dichloroacetyl chloride and finally with hydrazine hydrate, the course of the reaction in the process according to the invention can be outlined by the following formula scheme: ##STR8##
The formula (II) provides a general definition of the halogenoarenes to be used as starting materials in the process according to the invention for preparing compounds of the formula (I). In the formula (II), R.sup.1, R.sup.2 and R.sup.3 each preferably or in particular have those meanings which have already been mentioned above, in connection with the description of the compounds of the formula (I) according to the invention, as being preferred or as being particularly preferred for R.sup.1, R.sup.2 and R.sup.3 ; X preferably represents chlorine, bromine or iodine, in particular bromine or iodine.
The starting materials of the formula (II) are known and/or can be prepared by known processes (cf. J. Am. Chem. Soc. 81 (1959), 5643; J. Org. Chem. 27 (1962), 1426-1430; loc. cit. 59 (994), 7238-7242; J. Med. Chem. 13 (1970), 713-722).
The compounds of the formula (II) are obtained, for example, when ##STR9## in which R.sup.1, R.sup.2 and R.sup.3 are each as defined above bromine or iodine, if appropriate in the presence of a catalyst, such as, for example, iron, at temperatures between 0.degree. C. and 50.degree. C. (cf. the Preparation Examples), ##STR10## in which R.sup.1, R.sup.2 and R.sup.3 are each as defined above as, for example, hydrochloric acid (hydroge

REFERENCES:
patent: 5182295 (1993-01-01), Benoit et al.
patent: 5281571 (1994-01-01), Woodard et al.
patent: 5658489 (1997-08-01), Higashii et al.
Recueil des Travaux Chimiques des Pays-Bas, vol. 85, No. 2, Feb. 1966, pp. 167-174, W.P. Trompen et al.
Macromolecules, vol. 30, No. 7, Apr. 1997, pp. 1964-1997, M. Moroni et al.
Houben-Weyl: vol. E8b:, Nov. 29, 1994, pp. 472-474.
Journal of the American Chemical Society, vol. 93, Nr. 10, May 19, 1971, pp. 2471-2481, A.G. Hortmann et al.
Synthesis, Nr. 5, May 1996, Stuttgart DE, pp. 589-591, A.G. Mal'Kina et al.
Synthesis, Nr. 8, Aug. 1980, Stuttgart DE, pp. 627-630, S. Takahashi et al.

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