Organic compounds -- part of the class 532-570 series – Organic compounds – Nitriles
Patent
1994-08-17
1996-11-12
Richter, Johann
Organic compounds -- part of the class 532-570 series
Organic compounds
Nitriles
C07C25330
Patent
active
055741819
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This application is a 371 of PCT/NL92/00230, filed Dec. 17, 1992.
The invention relates to a process for the preparation of an aminonitrile by partially hydrogenating a nitrile compound with two or more nitrile groups in the presence of a catalyst which contains a metal from group 8 of the periodic system of the elements.
BACKGROUND OF THE INVENTION
Such a process is known from F. Mares, J. E. Galle, S. E. Diamond and F. J. Regina, Journal of Catalysis 112, (1988), pp. 145-156, according to which publication an alkane dinitrile, such as .alpha.,.omega.-butane dinitrile (succinonitrile), is hydrogenated in the presence of a catalyst consisting of finely divided rhodium halogenide on a magnesium oxide carrier. The catalyst is pretreated with sodium hydroxide, yielding metallic rhodium on a magnesium oxide carrier. During the hydrogenation reaction NH.sub.3 is supplied in an excess relative to the dinitrile. In the hydrogenation of succinonitrile, at a reaction temperature of 100.degree. C., a pressure of 50 atm (5 MPa) and a reaction time of 5.5 hours, a conversion of 89.4% and a selectivity to aminobutyronitrile of 87.3% is achieved. This corresponds to an aminobutyronitrile yield of 78%. Although this yield is high, a further increase in the yield is desirable. In addition to this, a large amount of undesirable by-product is formed (11.9% of the succinonitrile being converted into dimers and oligomers). The article also reports an .epsilon.-amino capronitrile yield of 66.6% from adiponitrile at 90% conversion. Dimers are formed in an amount of 2.7%.
SUMMARY AND OBJECTS OF THE INVENTION
It is the object of the present invention to provide a process for the preparation of an aminonitrile by means of a simple method, at a high reaction velocity and with a high aminonitrile yield, in which the formation of undesirable by-products is limited.
The object of the present invention is achieved in that the hydrogenation is carried out under virtually water-free reaction conditions and the catalyst has been treated with an alkanolate.
Surprisingly, it has been found that according to the present invention, aminonitrile yields in excess of 80% can be attained. Moreover, in the process of the invention there is no need to supply NH.sub.3 during the reaction. As byproduct virtually only oligoamine is formed, which can be worked up in the chemical industry, as opposed to dimers and oligomers, which are formed according to the process known from the art.
DETAILED DESCRIPTION OF THE INVENTION
The process according to the present invention involves preparing an aminonitrile by partially hydrogenating a nitrile compound having at least two nitrile groups with hydrogen under almost water-free reaction conditions in the presence of a catalyst. The catalyst contains a metal from group 8 of the Periodic Table of Elements and the catalyst has been treated with an alkanolate.
The process according to the invention is suitable for the partial hydrogenation of any nitrile compound with two or more nitrile groups.
Thus, for instance, .alpha.,.omega.-alkane dinitriles are suitable for conversion to their corresponding aminonitriles using the process according to the present invention. These alkane dinitriles are of a general formula NC--(CH.sub.2).sub.n --CN, n being an integer from 0 to 12. Preferably, n is an integer from 1 to 6. Examples are: malonitrile (n=1), succinonitrile (n=2), adiponitrile (n=4) and glutaronitrile (n=5). The process according to the present invention is particularly suitable for the hydrogenation of succinonitrile and adiponitrile.
The hydrogenation of .alpha.,.omega.-alkane dinitriles can be represented by the following reaction scheme: ##STR1## In this scheme the product of reaction (1) is the desired .omega.-aminoalkanenitrile, which can react further to form diamines in the presence of hydrogen according to reaction (2). k.sub.1 and k.sub.2 denote the rate constants of reactions (1) and (2). In a selective hydrogenation to the .omega.-amino alkane nitrile the ratio k.sub.1
REFERENCES:
patent: 1628190 (1927-05-01), Raney
patent: 4362671 (1982-12-01), Diamond et al.
patent: 5151543 (1992-09-01), Ziemecki
Mares, et al., Journal of Catalysis, 112, (1988), pp. 145-156.
Tomalia et al, Agnew. Chem. Int. Ed. Engl., 29:138-175 (1990).
Handbook of Chemistry and Physics, 59th Ed., CRC Press, 1978-1979.
Montgomery, Functional Group Activity of Promoted Raney Nickel Catalysts, Catalysis of Organic Reactions, 5:383-409 (1981).
Mares, Preparation and Characterization of a Novel Catalyst for the Hydrogenation of Dinitriles to Aminonitriles, Journal of Catalysis, 112:145-156 (1988).
Bosman Hubertus J. M.
Vandenbooren Franciscus H. A. M. J.
Cross Laura R.
DSM N.V.
Richter Johann
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