Patent GB-943697-A (GB)
Title: Production of 1,5 cyclo-octadiene from butadiene and catalysts for use therein
Inventor: KUTEPOW NIKOLAUS VON
IPC: B01J31/18
Filed: 1961-07-06
Abstract: The invention comprises a compound of the general formula: <FORM:0943697/C2/1> in which R is an alkyl or aromatic radical, Z is an a , b -unsaturated aldehyde or an a ,b -unsaturated nitrile, x is 2 or 3 and y is O or 1, the sum of x and y being les than or equal to 3.  Such compounds and similar phosphite-containing nickel complexes with less than four ligands may be obtained by reacting an organic nickel complex containing O-valent nickel and which is free from carbon monoxide groups with a triester of phosphorous acid in an inert solvent or diluent with substantial exclusion of oxygen. Suitable nickel complexes for use in the process are nickel (O)-bis-acrylonitrile, nickel(O)-bis-cinnamonitrile, nickel(O)-bis-fumaronitrile, and nickel(O)-bis-acrolein.  The group R in the phosphite may be the radical of a C1-C12 alkano or of a phenol or naphthol which may be substituted by alkyl or aryl radicals, alkoxy groups or halogen atoms, e.g. chlorine. The reaction is suitably carried out at from 20 DEG  to 120 DEG C. at normal pressure but higher or lower pressures may be used. Suitable solvents are hydrocarbons, ethers, and nitriles of lower fatty acids e.g. acetonitrile or propionitrile.  Examples are given for the production of the following complexes: <FORM:0943697/C2/2> <FORM:0943697/C2/3> <FORM:0943697/C2/4> <FORM:0943697/C2/5> <FORM:0943697/C2/6> tris-(tri-m-tolyl-phosphite)-nickel, and complexes obtained from nickel(O)-bis-acrylonitrile and tri-(a -naphthyl)-phosphite, tri-(2,4-dimethylphenyl)-phosphite, and tri-(p-tertiary-butylphenyl)-phosphite respectively.  The products are useful as catalysts for the dimerisation of butidiene to form cyclooctadiene-1,5 (see Division C5).ALSO:Cyclooctadiene-(1,5) is obtained by dimerization of butadiene at an elevated temperature of at least 50 DEG  C. in the presence of a catalyst consisting of a nickel complex with less than four ligands which has been obtained by reaction of an organic nickel complex compound free from carbon monoxide groups and containing O-valent nickel with a triester of phosphorous acid in an inert solvent or diluent with substantial exclusion of oxygen (see Division C2).  Particularly suitable catalysts are the complexes obtained from a triester of phosphorous acid and nickel (O) complexes with a ,b -unsaturated aldehydes or a ,b -unsaturated nitriles, e.g. acrolein, g -bromocrotonaldehyde, acrylonitrile, cinnamonitrile, and fumaronitrile. The triester of phosphorous acid may be derived from a C1-C12 alkanol or from a phenol or naphthol which may be substituted by an alkyl, aryl or alkoxy group or by a halogen atom, e.g. chlorine. The dimerization of the butadiene is preferably carried out in the presence of a solvent or diluent, e.g. a hyrocarbon, a liquid carboxylic acid amide, a cyclic ether, a nitrile or a ketone and a polymerization inhibitor, e.g. hydroquinone may be present.  Suitable dimerization temperatures are from 50 DEG  to 250 DEG C. and it is preferred to operate at an elevated pressure, e.g. 3 to 20 atmospheres.  Higher pressures may also be used by forcing in an inert gas such as nitrogen, rare gases, saturated or mono-olefinic gaseous hydrocarbons or carbon dioxide. The process may also be carried out at normal pressure, e.g. by blowing butadiene in gaseous form into a solution of the catalyst in a suitable solvent.  The butadiene may be used pure or in admixture with other hydrocarbons, e.g. those obtained in the cracking of higher hydrocarbons. The process may be carried out batchwise, continuously, or semi-continuously.  Small amounts of 4-vinyl-cyclohexene-(1) may be obtained as by-product.  Examples are given in which the following complexes are used as catalysts: <FORM:0943697/C3/1> <FORM:0943697/C3/2> <FORM:0943697/C3/3> <FORM:0943697/C3/4> <FORM:0943697/C3/5> tris-(tri m-tolyl phosphite nickel, nickel (O)-bis-(p-tertiarybutylphenyl)-phosphite, tris-(tri-phenyl phosphite) nickel and the complexes obtained from nickel (O)-bis-acrylonitrile and tri-2,4-dimethylphenyl phosphite tri-(a -naphthyl) phosphite and tri-4-isooctyl phenyl phosphite respectively.