Patent GB-827372-A (GB)
Title: Improvements in or relating to aroxyaliphatic compounds
Inventor: HEYWOOD BASIL JASON
IPC: C07C43/23
Filed: 1956-03-02
Abstract: The invention comprises phenoxy-alkanols and -alkenols of the general formula <FORM:0827372/IV (b)/1> wherein X represents a chlorine atom and Y represents a hydrogen or a chlorine atom or X represents a methyl radical or a hydrogen atom and Y represents a hydrogen, A represents a hydrocarbon chain containing 4 carbon atoms which may be saturated or unsaturated and may carry a methyl radical on the carbon atom adjacent to the phenoxy group and their esters with organic acids or inorganic oxy-acids.  Such compounds are employed in herbicidal compositions (see Group VI) and may be prepared by methods known per se for the preparation of phenoxy alkanols and their esters.  Thus the dibromide Br-Ar-Br, prepared from the corresponding diol or tetrahydrofuran, may be reacted with an alkali metal phenoxide and the remaining bromine atom converted to an ester group by reaction with an alkali metal salt, e.g. potassium acetate. Alternatively the g -(aroxy)-butyric acid or ester may be reduced with, e.g., lithium aluminium hydride.  The desired chlorine atoms may be introduced if necessary as the final stage of the preparation, e.g. d -(2 : 4-di-chlorophenoxy)-butanol, by chlorination of d  - (phenoxy) - butanol.  d  - (2 - methyl - 4 - chlorophenoxy) - n - butyl acetate is prepared by reacting d -(2-methyl-4-chlorophenoxy)-n-butyl bromide with potassium acetate. The corresponding d -(2 : 4-dichloro-phenoxy) compound is prepared in an analogous manner and the acetates are hydrolysed to the corresponding alcohols; d -2 : 4-dichlorophenoxybutyl alcohol is converted to the benzoate by reaction with benzoyl chloride and to the sodium sulphate ester by reaction with chlorsulphonic acid and sodium carbonate; d -2 : 4 : 5-trichlorophenoxypentanol is prepared by reducing g -2 : 4 : 5-trichlorophenoxyvaleric acid with lithium aluminium hydride in ether and 4-(2 : 4-dichlorophenoxy)-but-2-en-1-ol is obtained by reacting 1 : 4 - dichlorobut - 3 - yne with sodium 2 : 4 - dichloro-phenoxide to obtain 1-chloro-4-(2 : 4-dichloro-phenoxy)-but-2-yne which is reacted with potassium acetate to obtain 4-(2 : 4-dichloro-phenoxy)-but-2-yn-1-yl-acetate which is hydrolysed to obtain the corresponding alcohol which is hydrogenated in the presence of Raney nickel to obtain 4-(2 : 4-dichloro-phenoxy)-but-2-en-1-ol.ALSO:Herbicidal compositions contain a phenoxy-alkanol or -alkenol of the general formula <FORM:0827372/VI/1> wherein X represents a chlorine atom and Y represents hydrogen or a chlorine atom or X represents a methyl radical or a hydrogen atom and Y represents a hydrogen atom, A represents a hydrocarbon chain containing 4 carbon atoms, which may be saturated or unsaturated and may carry a methyl radical on the carbon adjacent to the phenoxy group or an ester thereof with an organic acid or inorganic oxyacid and an inert carrier or diluent. Other aroxyaliphatic compounds may be included in the compositions, e.g. 4-chloro-2-methyl- and 2 : 4-dichloro-phenoxy acetic acids and the corresponding g -substituted butyric acids and their derivatives. The compositions may contain solid diluents, e.g. talc or clay, or may be in the form of aqueous emulsions containing an ionic or non-ionic emulsifying agent.  Compositions for dispersion in water are described containing d  - (2 - methyl - 4 - chloro - phenoxy)-n-butyl acetate or d -(2 : 4-dichlorophenoxy)-n-butyl acetate in admixture with a polyethylene oxide non-ionic emulsifying agent with a castor oil base and a petroleum oil.  The p  Provisional Specification relates also to compositions containing, in addition, compounds disclosed in Specification 785,049.