Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Patent
1991-07-15
1994-04-05
Raymond, Richard L.
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
549427, 549497, 568 42, 568 43, 568306, 568308, 568313, 568343, 568345, 568376, 568388, 568390, 568417, C07C 4564, C07C 4566, C07D30906, C07D33502
Patent
active
053006542
DESCRIPTION:
BRIEF SUMMARY
FIELD OF INVENTION
This invention relates to methods for the preparation of .alpha., .beta.-unsaturated ketones represented by general formula (II) (hereinafter referred to as Compound II) ##STR1## where R is an aliphatic group having a side chain at the 1 position, an alicyclic group which may have substituents, a heterocyclic group which may have substituents or a phenyl group which may have substituents, which are important as intermediates for pharmaceuticals and agricultural chemicals, and to methods for the preparation of .beta.-hydroxyketones represented by general formula (I) (hereinafter referred to as Compound I) ##STR2## (where R is as defined above), which are synthetic intermediates for the said compound.
DESCRIPTION OF RELATED ART
Conventionally known methods for the preparation of Compound II include a method by aldol condensation of aldehyde with acetone [described in such documents as Ber. 40 4764 (1907)], a method by condensing aldehyde with acetone using piperidine-acetic acid as a catalyst [described in such documents as Indian J. Chem. 16B 970-972 (1978)], or a method by reacting aldehyde with metal salt of acetoacetic acid (Japanese open patent No. Sho 57-4930). However, when aldehyde with no .alpha.-hydrogen or with one .alpha.-hydrogen is used as a material, the said methods are inappropriate as industrial manufacturing methods because of low yield due to a large amount of byproducts produced usually or slow reaction, etc.
Existing methods by dehydrating .beta.-hydroxyketones cannot be employed industrially because of various problems if they are applied to .beta.-hydroxyketone with one .gamma.-hydrogen in particular.
For instance, a large amount of such an expensive compound as oxalic acid is required in the reaction, in water, using a dicarboxylic acid catalyst such as oxalic acid (described in such documents as West German patent No. 840,090). It has a problem from the economical viewpoint.
In the reaction using a strong acid catalyst such as sulfuric acid, in water and acetone (described in such documents as West German open patent No. 2,426,039), a large amount of .beta.-hydroxyketones remain and of by products, particularly .beta., .gamma.-unsaturated ketones, are produced in a large quantity.
In the reaction using p-toluenesulfonic acid catalyst in an organic solvent such as benzene [described in such documents as J. Am. Chem. Soc. 81 628-632 (1959)], the reaction proceeds smoothly by azeotropicdehydration. However, isomerization from .alpha., .beta.-unsaturated ketones to .beta., .gamma.-unsaturated ketones suddenly increase at around the end point of the reaction. Therefore it is difficult to control the .beta., .gamma.-unsaturated ketones.
Known methods for the preparation of .beta.-hydroxyketones include methods by synthesizing by aldol condensation of aldehyde with acetone [Ber. 40 4764 (1907), Ann. Chim. (Paris) 6 406-86 (1951)], and methods by reacting aldehyde with alkaline metal salt of acetoacetic acid (Japanese open patent No. Sho 55-141429). Generally the yield is low. The latter, in particular, has low yield when aldehyde with one .alpha.-hydrogen is used.
The object of this invention is to provide preparation methods for .beta.-hydroxyketones which can be used in particular for aldehyde with one .alpha.-hydrogen, which is a drawback of the above methods, and preparation methods for obtaining .alpha., .beta.-unsaturated ketones from the said .beta.-hydroxyketones with high yield.
SUMMARY OF THE INVENTION
The inventors carried out various studies to accomplish the above object, and found that it is possible to easily produce corresponding .beta.-hydroxyketones even if aldehyde with one .alpha.-hydrogen is used with high yield by a gentle reaction in an aqueous solution in the presence of perhydroisoindole and/or pyrrolidine which may have substituents and that the said .beta.-hydroxyketones are reacted in the presence of acid catalyst in a 2-phase system of water and water-insoluble organic solvent so as to give the intended .alpha., .beta.-unsaturated keyt
REFERENCES:
patent: 2088015, Wickert
patent: 4355184 (1982-10-01), Kaku et al.
M. Stiles, et al., J. Am. Chem. Soc., "Catalyst Selectivity in the Reactions of Unsymmetrical Ketones," 81, pp. 628-632 (1959).
V. Chandrasekharan, et al., Indian Journal of Chemistry, "Synthesis of 5-Alkyl & 5-Aryl-resorcinols", 16B, pp. 970-972 (1978).
H. Rupe et al., Ber., "Uber die Einwirkung von Semicarbazid auf ungesattigte Verbindungen," 40, pp. 6764-6770 (1907).
Kyotani Tadashi
Nakajima Masashi
Sawaki Mikio
Mason, Jr. Joseph C.
Nippon Soda Co. Ltd.
Oujevolk George B.
Raymond Richard L.
Smith Ronald E.
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