| 摘要 |
<p>2 : 3 : 6 - Trichlorobenzoic acid or a mixture of isomeric trichlorobenzoic acids including the 2 : 3 : 6-isomer is produced by converting 2 : 3 : 6-trichlorobenzyl halide (e.g. chloride or bromide) or a mixture of isomeric trichlorobenzyl halides including the 2 : 3 : 6-isomer (preferably in an amount of at least 50 per cent) into an ester or esters: <FORM:0817173/IV (b)/1> R being H, CH3, C2H5 or other organic radical, and oxidizing the product with, for example, nitric acid to the trichlorobenzoic acid, which may be converted into its salts. The trichlorobenzyl chloride or bromide may be produced by converting toluene, o- or m-chlorotoluene, dichlorotoluenes or mixtures thereof to a mixture of trichloro isomers, and halogenating the side-chain. The mixed isomers contain mainly the 2 : 3 : 6-trichlorotoluene. In examples, o-chlortoluene is chlorinated to the 2 : 3 : 6-trichlorotoluene in various runs, or toluene is trichlorinated, the trichlorotoluene mixtures produced are chlorinated or brominated in the side-chain to trichlorobenzyl chloride or bromide, and this is converted to formate, acetate, oxalate, malonate, glycolate, levulinate, or benzoate, and the ester oxidized with nitric acid to the trichlorobenzoic acid as isomeric mixture, which may be isolated as its salts. Specification 817,174, [Group VI], is referred to.</p> |
