Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Reexamination Certificate
1999-10-22
2002-01-22
Davis, Brian J. (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
C568S835000
Reexamination Certificate
active
06340775
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
A subject of the present invention is a process for reduction of a carbonyl compound. More precisely, the invention relates to a process for reduction of an aldehyde and/or of a ketone.
2. Description of Related Art
Various processes exist for reduction of carbonyl compounds to alcohols. In particular, reduction of aldehydes and ketones to alcohols by a hydrogenation process, in the presence of Raney nickel, is known.
The problem that arises is that the reduction of an aldehyde or of a ketone, carried out according to the aforesaid process, is a reaction that is not stereoselective, so that a mixture of stereo-isomers is obtained. This is the case when we carry out the reduction of a substituted cyclohexanone, thus resulting in a thermodynamic mixture of the stereo-isomers.
The objective of the present invention is to provide a simple reduction process that is applicable to any carbonyl compound, and more particularly to carbonyl compounds for which it is required to obtain a majority stereo-isomer.
Furthermore, Van Bekkum et al. have described the reduction of 4-tert.-butylcyclohexanone to cis-4-tert.-butylcyclohexanol, catalysed by a BEA zeofite [J. Chem. Soc., Chem. Commun., p. 1859-60 (1995)].
Use of the said catalyst on an industrial scale poses a problem because the productivity of the catalyst is inadequate and it would be necessary to have an extremely large reactor.
The aim of the present invention is to provide a process by which the aforesaid drawbacks can be obviated.
SUMMARY OF THE INVENTION
There has now been found, and this is what constitutes a subject of the present invention, a process for reduction of a carbonyl compound to the corresponding alcohol, by reaction of the said carbonyl compound with an alcohol in the presence of a zeolite catalyst, characterized by the fact that it comprises:
mixing, in any manner whatever, the carbonyl compound and the alcohol,
passing the said mixture over a catalyst bed containing at least one zeolite,
subjecting the reaction mixture leaving the catalyst bed to recirculation over the catalyst bed, for a number of times that is sufficient to obtain the desired degree of conversion of the substrate.
REFERENCES:
patent: 3980718 (1976-09-01), Shabtai et al.
Database CAPLUS on STN, Acc. No. 1967:121862, Kaye, ‘Automatic recycling apparatus for elution chromatography: isolation fo cis-4-tert-butylcyclohexanol.’ Mikrochim. Acta (1967), 2, pp. 322-327 (abstract).*
E.J. Creyghton et al, “Stereoselective reduction of 4-tert-butylcyclohexanone to cis-4-tert-butylcyclohexanol catalysed by zeolite BEA”, Journal of the Chemical Society, Chemical Communications, No. 18, Sep. 21, 1995, Letchworth, GB, pp. 1859-1860, XP002038921.
Jacquot Roland
Spagnol Michel
Davis Brian J.
Rhodia Chimie
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