Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Patent
1996-05-16
1997-07-08
Owens, Amelia
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C07D30702
Patent
active
056463073
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a process for the preparation of .gamma.-butyrolactone.
Havel et al (J. Org. Chem. 41, 513 (1976)) produced .gamma.-butyrolactone by oxidation of 2,3-dihydrofuran with triplet oxygen. .gamma.-butyrolactone forms in this reaction only in a yield of 1.4%. Piancatelli et al (Tetrahrahedron Lett. 39, 3483 (1977)) oxidized 2,3-dihydrofuran by means of pyridinium chlorochromate. The expensive oxidizing agent pyridinium chlorochromate is consumed in this reaction in stoichiometric amounts, for which reason this process is unsuitable, since it is uneconomical for commercial use.
It has not hitherto been possible to obtain .gamma.-butyrolactone starting from 2,5-dihydrofuran by a direct method. Alper et al (J. Mol. Cat. 72, 143 (1992)) described the cobalt(I) chloride-catalyzed oxidation of 2,5-dihydrofuran with oxygen to form 2-buten-4-olide of the formula I ##STR1## whose C--C double bond has to be hydrogenated in a subsequent reaction before .gamma.-butyrolactone is obtained. Thus this process is also uneconomical.
According to EP-A 24,770, the reaction of 2,5-dihydrofuran in the liquid phase with water over a platinum/palladium-on-aluminum oxide catalyst leads to 4-hydroxybutyraldehyde. .gamma.-Butyrolactone was not found in this reaction.
.gamma.-Butyrolactone is a chemical required in large quantities and serves, for example, as solvent for polyacrylonitrile, cellulose acetate, polystyrene, shellac, and resins and is also used as starting material for the preparation of economically important products such as pyrrolidone, N-methyl pyrrolidone and poly(vinyl pyrrolidone).
It was the object of the present invention to provide a process which makes possible the preparation of .gamma.-butyrolactone, starting from 2,5-dihydrofuran or 2,3-dihydrofuran, in an economical manner. In particular it was desirable to find a way to prepare .gamma.-butyrolactone starting from 2,5-dihydrofuran directly in a single stage.
Accordingly we have found a process for the preparation of .gamma.-butyrolactone, which is characterized in that 2,5-dihydrofuran or 2,3-dihydrofuran or a mixture of these two dihydrofurans is caused to react in the gas phase in the presence of water and in the presence or absence of additional hydrogen at elevated temperature over a hydrogenating catalyst.
Although the chemical reaction mechanism for the reaction underlying the process according to the invention is still unknown, it is thought that this reaction could occur according to the following reaction scheme. If this is so, the 2,5-dihydrofuran II is initially isomerized over the hydrogenating catalyst according to equation (1) to form 2,3-dihydrofuran III: ##STR2##
Then water is possibly added to the 2,3-dihydrofuran according to equation (2): ##STR3## in which 2-hydroxytetrahydrofuran of the formula IV forms, which is in a balanced relationship with its open-chain isomer 4-hydroxybutyraldehyde of the formula V ##STR4##
2-Hydroxytetrahydrofuran IV is then presumably hydrogenated by the hydrogenation catalyst according to equation (3) ##STR5## to form .gamma.-butyrolactone of the formula VI. The hydrogenation catalyst employed would thus act as a dehydrogenation catalyst. Since the catalysts which can be used in the invention are usually employed as hydrogenation catalysts in industry, we will continue to call these catalysts "hydrogenation catalysts" for the purposes of this application in spite of their dehydrogenating effect in the process according to the invention. As mentioned above, the above reaction mechanism is merely an attempt at an explanation of the chemical events taking place at the catalyst in the process according to the invention, which have not been investigated in greater detail. This idea concerning the reaction mechanism is substantially supported by the observations that both 2,5-dihydrofuran and 2,3-dihydrofuran can be employed in the process of the invention and that the said process can be carried out in the absence of additional hydrogen, and is also supported by the by-products found.
In
REFERENCES:
patent: 5034545 (1991-07-01), Fischer
patent: 5082956 (1992-01-01), Monnier et al.
Methoden der Org. Chem., vol. V, 1c, pp. 16-26 (1980).
J. Mol. Cat., 72 (1992) 143-152.
Tetrahedron Lett. 39, (1977) pp. 3483-3484.
J. Or. Chem., vol. 41, No. 3, 1976 p. 513.
Bull. Soc. Chem., France 668 (1950).
J.C.S. Perkin II, J. Chem. Soc. II 366, (1972).
Fischer Rolf
Pinkos Rolf
BASF - Aktiengesellschaft
Owens Amelia
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