GB890542A - Production of benzene and its trisubstituted and hexasubstituted derivatives - Google Patents

Abstract

The trimerization of acetylenes to benzenes is effected in the presence as catalyst of:- (i) an iron (III) halide or a titanium or nickel compound (ii) a metal of Group Ia, IIa, IIb, IIIa or the lanthanide series and (iii) a halide of an element of Group IIb, IIIa, IVa or Va, aluminium or an aluminium halide being essentially present; the Periodic Table references are to one in which the transition elements are in sub-Groups B and Group VIII and the remaining elements in sub-Groups A. In the catalyst system the compound (i) may be a lower alkyl titanate, e.g. titanium tetra-methylate, -ethylate or -propylate, a titanium halide, e.g. the tri- or tetra-chloride or -bromide, a titanium ester halide, e.g. diethoxy titanium dichloride or dibutoxy titanium dibromide, organo-titanium halides, e.g. bis-cyclopentadienyl titanium dichloride or dimethyl titanium dibromide, ferric chloride or bromide, or nickel salts or chelate complexes, e.g. nickelous chloride, bromide, iodide, carbonate, formate, acetate, oxalate, benzoate, oleate, sulphate or nitrate nickel acetylacetonate, nickel acetoacetic acid ester, nickel benzoyl acetonate, nickel monoacetyl-acetonate ethylate, nickel dimethylglyoxime, nickelous oxide, hydroxide or sulphide or nickelic hydroxide. Nickel compounds are preferably anhydrous, those containing water of crystallization may be used with an excess of metal (ii). The metal (ii) may be lithium, sodium, potassium, berryllium, magnesium, calcium, strontium, barium, aluminium, gallium, indium, zinc or cerium and preferably has a large surface area. The halide (iii) may be a chloride or bromide of boron, aluminium, gallium, indium, thallium, silicon, tin, zinc, phosphorus, antimony or bismuth. Where compound (i) is a halide and metal (ii) is aluminium, aluminium halide as halide (iii) may be formed in situ. A compound forming a complex with the halide (iii) may be used, e.g. an ether, thioether, sulphoxide nitrone, tertiary base, or alkali or alkaline earth halide, hydroxide, hydride or cyanide, typical examples being anisol, phenetol, diethyl ether, diphenyl ether, diphenylene oxide, diphenyl sulphide, thiobutyric acid, quinoline, triethylamine, sodium chloride, magnesium chloride, calcium chloride, lithium hydride, calcium hydride, and potassium cyanide. The mol. ratio of (i) to redox equivalent of (ii) to mol. of (iii) may be from 1:300:100 to 1:10:10 or the titanium compound may be in excess and the mol. ratio of the sum of (i) and (iii) to complex forming compound may be 1:0,2-3. The total amount of catalyst may be as low as 0,3% by weight of the acetylene. Two or all of the components of the catalyst are preferably ground in a ball mill at up to 150 DEG C. for 1-10 hours in the solvent to be used which is present in an amount of 0,2 to 0,5 that of the acetylene and may be, e.g. benzene, toluene, xylene, pentane, ethylbenzene, cumene, chlorobenzene, heptane, cyclohexane, iso-octane or tetrahydrofurane. Specification 802,510 is referred to.ALSO:The production of benzene or tri- or hexasubstituted benzenes by the trimerisation of acetylene or a mono- or di-substituted acetylene is effected in the presence as catalyst of (i) an iron (III) halide or a titanium or nickel compound; (ii) a metal of group Ia, IIa, IIba or the lanthanide series; and (iii) a halide of an element of group IIb, IIIa, IVa or Va; aluminium or an aluminium halide being essentially present; the Periodic Table references are to one in which the transition elements are in sub-groups B and group VIII and the remaining elements in sub-groups A. The starting material may be acetylene propine, butine-1, pentine-1, hexine-1, octine-1, dodecine-1, octadecine-9, octadecine-1, vinyl acetylene, phenyl acetylene, cyclohexyl acetylene, benzyl acetylene, butine-2, hexine-3, methyl ethyl acetylene or tolane. In the catalyst system the compound (i) may be a lower alkyl titanate, e.g. titanium tetra-methylate, -ethylate or -propylate, a titanium halide, e.g. the tri- or tetra-chloride or -bromide, a titanium ester halide, e.g. diethoxy titanium dichloride or dibutoxy titanium dibromide, organo-titanium halides, e.g. bis-cyclopentadienyl titanium dichloride or dimethyl titanium dibromide, ferric chloride or bromide, or nickel salts or chelate complexes, e.g. nickelous chloride, bromide, iodide, carbonate, formate, acetate, oxalate, benzoate, oleate, sulphate or nitrate nickel acetylacetonate, nickel acetoacetic acid ester, nickel benzoyl acetonate nickel monoacetylacetonate ethylate, nickel dimethylglyoxime, nickelous oxide, hydroxide or sulphide or nickelic hydroxide. Nickel compounds are preferably anhydrous, those containing water of crystallisation may beused with an excess of metal (ii). The metal (ii) may be lithium sodium, potassium, beryllium, magnesium, calcium, strontium, barium, aluminium, gallium, indium, zinc or cerium and preferably has a large surface area. The halide (iii) may be a chloride or bromide of boron, aluminium, gallium, indium, thallium, silicon, tin, zinc, phosphorus, antimony or bismuth. Where compound (i) is a halide and metal (ii) is aluminium, aluminium halide as halide (iii) may be formed in situ. A compound forming a complex with the halide (iii) may be used, e.g. an ether, thioether, sulphoxide nitrone, tertiary base, or alkali or alkaline earth halide, hydroxide, hydride or cyanide, typical examples being anisol, phenetol, diethyl ether, diphenyl ether, diphenylene oxide, diphenyl sulphide, thiobutyric acid, quinoline, triethylamine, sodium chloride, magnesium chloride, calcium chloride, lithium hydride, calcium hydride, and potassium cyanide. The mol ratio of (i) to redox equivalent of (ii) to mol of (iii) may be from 1 : 300 : 100 to 1 : 10 : 10 or the titanium compound may be in excess and the mol ratio of the sum of (i) and (ii) to complex forming compound may be 1 : 0.2-3. The total amount of catalyst may be as low as 0.3% by weight of the acetylene. Two or all of the components of the catalyst are preferably ground in a ball mill at up to 150 DEG C. for 1-10 hours in the solvent to be used which is present in an amount of 0.2 to 0.5 that of the acetylene and may be, e.g. benzene, toluene, xylene, pentane, ethylbenzene, cumene, chlorobenzene, heptane, cyclohexane, iso-octane, or tetrahydrofurane. The reaction temperature may be -5 DEG C. to 150 DEG C. and the pressure preferably atmospheric or up to 10 atmospheres gauge if low-boiling reactants are used.