Patent GB-951449-A (GB)
Title: Improvements in or relating to nuclear-chlorinated aromatic compounds
Filed: 1960-04-27
Abstract: The invention comprises halo-benzaldoximes (other than alpha-2, 6-dichlorobenzaldoxime, i.e. the trans-isomer) and their acyl derivatives having the general formula: <FORM:0951449/C2/1> wherein Hlg represents a halogen atom, R1 is a halogen atom or an alkyl group containing 1 to 6 carbon atoms, and X is an acyl residue of a monocarboxylic acid when n=1, or X is an acyl residue of a dicarboxylic acid when n=2.  Examples 1 and 10 describe the preparation of beta -2, 6- dichlorobenzaldoxime by heating a solution of 2, 6-dichlorobenzaldehyde in ethanol with an aqueous solution of sodium hydroxylamine di- and mono-sulphonate, respectively. In Example 5, an ethereal solution of beta-2, 6-dichlorobenzaldoxime is treated with 2, 3, 6-trichlorophenylacetyl chloride and powdered sodium bicarbonate.  The mixture is filtered; and the filtrate is washed with dilute hydrochloric acid, dried over anhydrous sodium sulphate, filtered and evaporated, whereby the beta-2, 3, 6-trichlorophenylacetyloxime of 2, 6-dichlorobenzaldehyde is obtained.  Example 8 describes the preparation of the alpha-2, 3, 6-trichlorophenylacetyloxime of 2, 6-dichlorobenzaldehyde by reacting trichlorophenylacetyl chloride, in the presence of collidine, with alpha-2, 6-dichlorobenzaldehyde (which is itself obtained by reacting dichlorobenzaldehyde with hydroxylamine). Examples 4 and 7 describe the preparation of the beta- and alpha-2-methyl-4-chlorophenoxyacetyl oximes, respectively, of 2, 6-dichlorobenzaldehyde. Examples 2, 3, 6 and 9 relate to the acetyl-, beta-caproyl-, beta-chloroacetyl-, and alpha-2, 4-dichlorophenoxyacetyl-oximes of 2, 6-dichlorobenzaldehyde, respectively.  A list is given of other oximes within the scope of the invention; this list includes:  the alpha-41-nitrophenylacetyl-oxime of 2-chloro-6-methylbenzaldehyde, the beta-ethoxyacetyloxime of 2-bromo -6- chlorobenzaldehyde, the alpha-carboxyethyl-propionyl-oxime of 2-bromo -6- chlorobenzaldehyde, the beta acetyloxime of 2, 6-dibromobenzaldehyde, and the alpha-2, 4-dichlorophenoxyacetyloxime of 2-chloro -6- fluorobenzaldehyde. These halobenzaldoximes and their acyl derivatives have use in the production of compositions for combating weeds or otherwise influencing plant growth.  Specification 948,263 is referred to.ALSO:Compositions comprising a halo-benzaldoxime (other than alpha-2,6-dichlorobenzaldoxime, i.e. the transisomer) having the general formula <FORM:0951449/A5-A6/1> wherein Hlg represents a halogen atom, R1 is a halogen atom or an alkyl group containing 1 to 6 carbon atoms, and X is an acyl residue of a monocarboxylic acid when n = 1, or X is an acyl radical of a dicarboxylic acid when n = 2, in admixture with a solid or liquid inert carrier, are effective in inhibiting the growth of weeds or otherwise influencing plant growth.  Specific active compounds are: alpha-2,6-dichlorobenzaldoxime acetate, 2,6-dichlorobenzaldoxime caproate, and the 2,4-dichlorophenoxyacetyl-, 2 - methyl - 4 - chlorophenoxyacetyl-, and 2,3,6 - trichlorophenylacetyloximes of 2,6-dichlorobenzaldehyde.  In general, the beta-isomers have a larger influence on the growth of plants than the corresponding alpha-isomers.  Specified carriers are: kaolin, chalk, pipeclay, dolomite, attapulgite, kieselguhr; and benzene, toluene or xylene, mixed with acetone or cyclohexanone.  Wetting agents such as fatty alcohol sulphates or alkylaryl-sulphonates, as well as dispersing agents such as lignin sulphonates, may be included in the compositions.  Specified forms are spraying powders, miscible oils, dusts, solutions and suspensions.  Specification 948,263 is referred to.