| 摘要 |
The invention comprises the a : a -dichlorobutyrates of haloaryloxyalkanols wherein the haloaryl radical of the said haloaryloxyalkanol is of the benzene series and the alkanol radical contains from 1 to 4 carbon atoms inclusive. The compounds may be prepared by reacting a : a -dichlorobutyric acid with the haloaryloxyalkanol. The reaction may be carried out in a water-immiscible solvent such as ethylene dichloride, chlorobenzene and toluene, with continuous removal of the water of reaction by azeotropic distillation. An esterification catalyst such as sulphuric acid, a phenol sulphonic acid or a cation exchange resin in the acid form may be used. The compounds are used as herbicides, insecticides and parasiticides (see Group VI). In examples the a : a -dichlorobutyric acid esters of the following haloaryloxyalkanols are prepared: 2 - (21 : 41 : 51 - trichlorophenoxy) - ethanol or -1-propanol, 2-(31 : 41-dichlorophenoxy)-ethanol, 1 - (31 : 41 - dichlorophenoxy) - 2 - propanol, 2 - (41 - chloro - 21 - methylphenoxy) - ethanol, 1 - (pentachlorophenoxy)-2-propanol, 2-(41-bromo-or - chloro-phenoxy)-ethanol, 2-(21-bromo - 41 - chlorophenoxy) - ethanol, 2 - (21 : 41-dibromophenoxy) - ethanol, 3 - (21 : 41 - dichlorophenoxy)-1-butanol and 3-(41-chlorophenoxy)-1-propanol. The haloaryloxyalkanol starting materials are prepared by reacting an alkali metal salt of the appropriate phenol with a monohaloaliphatic alcohol such as ethylene or propylene chlorohydrin, 3-bromo- or -chloro-1-propanol, 3-chloro-2-propanol and 3-chloro-1-butanol. Specification 714,559 is referred to.ALSO:The haloaryloxyalkyl esters of a : a -dichlorobutyric acid, wherein the haloaryl radical is of the benzene series and the alkyl radical contains from 1 to 4 carbon atoms (see Group IV (b)) may be used as herbicides, insecticides, bactericides, and for soil sterilisation. They may be mixed with inert finely-divided solids and used as dusts dispersed in water with the aid of a wetting agent and used as sprays, or used as constituents of oil-in-water emulsions. Specified compounds include 2-(21 : 41 : 51-trichlorophenoxy)-ethyl or -1-propyl, 2-(41-chloro-21-methylphenoxy) - ethyl, 2 - (21 - bromo - 41 - chlorophenoxy) ethyl and 2-(21 : 41-dibromophenoxy)-ethyl a : a -dichlorobutyrates. |
