Methyl 3,6-dichloro-2-methoxybenzoate

The photostimulated reaction of o-, m-, and p-C6H4Cl2 with Mc3Sn ions gives disubstitution in 58%, 90%, and 88% yield, respectively [39] in addition, methyl 2,5-dichlorobenzoate and methyl 3,6-dichloro-2-methoxybenzoate afford bistannylated aromatic compounds in 99% and 64% yields, respectively [40]. Disubstitution products are also obtained by the reaction of 2,6-and 3,5-dichloropyridine under photoinitiation in about 80% yield (Scheme 10.26). Even trisubstitution is possible by the photoinduced reaction of 1,3,5-C6H3C13 with Me3Sn ions in liquid ammonia, in 71% yield [39]. 

In a recent investigation, the photostimulated reaction of methyl 2,5-dichlorobenzoate 46 (R=H) or methyl 3,6-dichloro-2-methoxybenzoate 71 (R = OMe) with PhS ions in excess in liquid ammonia was studied (Eq. 10.27). Compound 46 afforded mainly the product 72 (R=H, 88%) with retention of the chlorine, whereas 71 yielded the disubstitution product 73 (R=OMe) with 80% yield. The different reactivity observed was explained on the basis of the activation energy necessary for the from the tr to the a of the C—Cl bond and the fragmentation of the radical anion intermediates [65] ... 

Preparation by reaction of methyl 3,6-dichloro-2-methoxybenzoate with carban-ion reagent (78% yield), followed by ether cleavage (95%) [1879],... 

Methylation of 2,4-dichlorophenoxyacetic acid and 3,6-dichloro-2-methoxybenzoic acid in soil samples was examined using trimeth-ylphenylammonium hydroxide prior to supercritical extraction with C02 (Hawthorne et al. 1992). Although recoveries of these compounds were apparently limited by competition for the reagent of components of the soil matrix, this procedure possesses obvious advantages for polar analytes such as carboxylic acids and is capable of extension to other analytes. 

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