GB1067034A - Halogenated alkoxyalkoxybenzonitriles - Google Patents

Abstract

The invention comprises compounds of the formula <FORM:1067034/C2/1> in which R1 denotes a straight or branched chain alkyl or alkenyl group of 1-18 carbon atoms, R2 denotes hydrogen or a straight or branched chain alkyl or alkenyl group of 1-18 carbon atoms, X1 denotes a halogen atom and X2 denotes a halogen atom or a nitro group. The compounds may be prepared by reacting a metallic salt of a phenol of the formula <FORM:1067034/C2/2> in which M denotes a metal, with an alkoxyalkyl halide of the formula R1OCH(R2)Halogen. Alternatively, the compounds may be prepared by halogenating a corresponding unhalogenated or monohalogenated compound. Halogenation may be effected with elementary halogen, or chlorination may be effected with a mixture of sulphur monochloride, sulphuryl chloride and aluminium chloride, or bromation may be effected with sodium or potassium hypobromite, or iodination may be effected with iodine monochloride or with an alkali-metal iodide and an oxidizing agent. The halogenation may be effected in two stages, and different halogens may be introduced in each stage. As a further alternative, the compounds may be prepared by treating an oxime of the formula <FORM:1067034/C2/3> by known methods for the conversion of oximes to nitriles. An example is given of the preparation of 3,5 - diiodo - 4 - methoxymethoxybenzonitrile by reacting 3,5-diiodo-4-hydroxybenzonitrile sodium salt with monochlorodimethyl ether in tetramethylene sulphone. Other products similarly obtainable are 3,5-dichloro- and 3,5 - dibromo - 4 - methoxymethoxybenzonitrile, 3,5 - diiodo - 4 - n - octyloxymethoxybenzonitrile, and 3 - iodo - 4 - methoxymethoxy - 5 - nitrobenzonitrile. Reference is made also to the production of a 3-chloro-5-bromo-benzonitrile derivative of Formula I. The products are useful as herbicides (see Division A5). Oximes of Formula III above are obtainable from hydroxylamine and the corresponding benzaldehyde derivatives, which are themselves obtainable by treating a metallic derivative of the corresponding 4-hydroxybenzaldehyde with an alkoxyalkyl halide. n-Octyloxymethyl chloride, used in the preparation of one of the products of the example, is prepared by treating a mixture of n-octyl alcohol and paraformaldehyde with dry hydrogen chloride.ALSO:As selective herbicides, use is made of compounds of the formula <FORM:1067034/A5-A6/1> in which R1 denotes a straight or branched chain alkyl or alkenyl group of 1-18 carbon atoms, R2 denotes hydrogen or a straight or branched chain alkyl or alkenyl group of 1-18 carbon atoms, X1 denotes a halogen atom and X2 denotes a halogen atom or a nitro group (see Division C2). The compounds may be formulated as wettable powders, granules, solutions or emulsions, including self-emulsifiable concentrates, or aerosol preparations with the aid of solid or liquid diluents, carriers, or ionic or non-ionic surface-active agents, a number of each of which are specified. The compositions may include other herbicides, particularly those of the phenoxyalkanoic acid type. The use of the compositions for controlling annual broad-leafed weeds and for destroying potato haulms is stressed. Examples are given.