GB887411A - Preparation of ª-, ª--disubstituted-ª--cyanoketones - Google Patents

Abstract

b ,b -Disubstituted-b -cyanoketones of formula <FORM:0887411/IV (b)/1> where R1 is methyl or ethyl, R2 is hydrogen, methyl or ethyl, the R1 substituents being the same or different and the compounds containing a total of 7-9 carbon atoms are prepared by hydrocyanation of a ,b -unsaturated ketones of formula <FORM:0887411/IV (b)/2> or the tautomeric b -g -unsaturated ketones, the process comprising gradually bringing together, at the reaction temperature, preformed mixtures of (a) an alkaline catalyst capable of generating cyanide ions and said unsaturated ketone or the desired cyanoketone product and (b) hydrocyanic acid and the unsaturated ketone reactant at a rate which is substantially that at which the HCN reacts with the ketone, and carrying out the reaction at superatmospheric pressure and at a temperature of 130 DEG C.-350 DEG C. The process may be carried out batchwise, generally at 130 DEG C.-275 DEG C. and pressures of 25-250 p.s.i.g., e.g. autogenous pressure, or continuously, e.g. at 25-10,000 p.s.i.g.; an inert gas may be present. A volatile, highly-polar inert organic solvent may be present, e.g. dimethylformamide, dimethylacetamide, 1 - methyl - 2 - pyrrolidinone, 1, 5 - dimethyl - 2 - pyrrolidinone or 1, 3 - dimethyl - 2 - imidazolidine. Suitable catalysts include alkali metals and their carbonates, alkali and alkaline earth metal lower alkoxides, oxides, hydroxides, peroxides and cyanides, t-amines and quaternary ammonium bases. About 1%-20% by weight of catalyst may be present. The catalyst may be neutralised at the end of the reaction. The products are stated to be useful as solvents for polymers and as insecticides and fungicides (see Group VI). Specification 730,209 is referred to.ALSO:Insecticidal and fungicidal compositions comprise a b ,b - disubstituted - b - cyanoketone of formula <FORM:0887411/VI/1> where R1 is methyl or ethyl, R2 is hydrogen, methyl or ethyl, the R1 substituents being the same or different and the compounds containing a total of 7-9 carbon atoms, together with an inert solid or liquid carrier, e.g. a hydrocarbon. (For preparation see Group IV (a).) Specification 730,209 is referred to.