GB1250991A - - Google Patents

Abstract

1,250,991. Electrohydrodimerization process. BADISCHE ANILIN- & SODA-FABRIK A.G. 3 Jan., 1969 [5 Jan., 1968], No.551/69. Heading C2C. [Also in Division C7] Adiponitrile is produced by direct electrochemical hydrodimerization of acrylonitrile in an electrolytic cell without a diaphragm in the presence of an aqueous conducting solution containing a mixture of tetramethylammonium and tetraethylammonium cations in the ratio by weight (calculated as (CH 3 ) 4 N<SP>+</SP>: (C 2 H 5 ) 4 N<SP>+</SP> but including any tetramethylammonium and tetraethylammonium groups present in any undissociated compounds thereof) of from 1: 4 to 4:1 at a pH in the range from 7À0 to 9À5 and under relative movement between the electrolyte and electrodes (e.g. the electrolyte and/or electrodes may be vibrated). The pH may be kept within the specified range by the continuous addition of base. Thus, a tetraethyl ammonium salt (or tetramethylammonium salt) may be placed in the cell and the pH value be adjusted with tetramethyl ammonium hydroxide (or tetraethylammonium hydroxide). Current densities, voltages and temperatures may be 10-80 A/dm<SP>2</SP>, 5-12 volts and 20-40‹ C. The tetraethylammonium and tetramethylammonium salts may be derived from the following sulphonic acids: benzene-, toluene-, cumene-, ethylbenzene-, naphthalene-, methane- and ethane-sulphonic acids or may be derived from methyl- or ethyl-sulphuric acid or may be sulphates, phosphates, perchlorates, fluorides, tetrafluoborates or fluorosulphonates. Solvents which may be added to the electrolyte are acetonitrile, specified ethers, dimethyl formamide, dimethyl sulphoxide, dimethyl sulphone or specified alcohols.