GB1477782A - Electrolytic hydrodimerization of olefinic hydrocarbons - Google Patents

Abstract

1477782 Electrolytic hydrodimerization of olefinic compounds MONSANTO CO 28 July 1975 [15 Aug 1974] 31455/75 Addition to 1419155 Heading C2C [Also in Division C7] An olefinic compound R 2 C = CRX where X=-CN, -CONR 2 or COOR<SP>1</SP>, R<SP>1</SP> being C 1 -C 4 alkyl, and R being R<SP>1</SP> or H, is cathodically electro-hydrodimerized by electrolysing an aqueous solution containing #0À1 wt. per cent of said compound, #10<SP>-5</SP> mole/1. of monoquaternary phosphonium or multi-valent multiquaternary ammonium or phosphonium ions, #0À1 wt. per cent of a conductive salt, and an amount sufficient to inhibit H 2 -formation at the cathode of Y 2 N(ZYN) n R<SP>11</SP>COOM where Y=H, R<SP>11</SP>COOM, (CH 2 ) m+1 OH, or C 1 -C 20 alkyl, R<SP>11</SP> = (CH 2 ) m or CHR<SP>111</SP>, R<SP>111</SP> being OH, COOM, (CH 2 ) m COOM, C 1 -C 8 alkyl, hydroxyalkyl or hydroxyphenyl, Z = divalent C 2 -C 6 hydrocarbon, M=H, NH 4 or alkali metal, m= 1, 2, n=0-4 and at least one Y-R<SP>11</SP>COOM or (CH 2 ) m+1 OH. The examples all relate to dimerizing acrylonitrile to adiponitrile, but other possible starting compounds are listed, as are suitable quaternary salts. Said conductive salt can be a quaternary phosphonium or ammonium phosphate, sulphate, alkylsulphate or arylsulphate, or a quaternaryphosphonium or -ammonium or alkali metal orthophosphate, borate, perchlorate, carbonate or sulphate, condensed borates and phosphates may be used. The electrolyte may contain an undissolved organic phase, e.g. containing said olefinic compound, plus its reaction product and by-products. The cell may have a cation permeable membrane, or diaphragm, or be undivided; the anode may be Pt, Ru, Ni, Pb, PbO 2 , Fe, steel or magnetite and the cathode Cd, Hg, Th, Pb, Zn, Mn, Sn or graphite; anodecathode spacing is 1-12À5 mm., the electrolyte velocity between the electrodes is #0À3 m./sec., the C.D. 0À01-1À5 A/cm.<SP>2</SP>, the temperature 5-75‹ C., the pH 2-11, and the pressure at or above atmospheric.