40932-60-3Relevant articles and documents
A new process to prepare 3,6-dichloro-2-hydroxybenzoic acid, the penultimate intermediate in the synthesis of herbicide dicamba
Walker, Daniel P.,Harris, G. Davis,Carroll, Jeffery N.,Boehm, Terri L.,McReynolds, Matthew D.,Struble, Justin R.,van Herpt, Jochem,van Zwieten, Don,Koeller, Kevin J.,Bore, Mangesh
supporting information, p. 1032 - 1036 (2019/03/17)
Glyphosate [N-(phosphonomethyl)glycine] is a broad spectrum, post-emergent herbicide that is among the most widely used agrochemicals globally. Over the past 30 years, there has been a development of glyphosate-resistant weeds, which pose a significant challenge to growers and crop scientists, resulting in lower crop yields and increased costs. 3,6-Dichloro-2-methoxybenzoic acid (dicamba) is the active ingredient in XtendiMax a standalone herbicide developed by Bayer Crop Science to control broadleaf weeds, including glyphosate-resistant species. 3,6-Dichloro-2-hydroxybenzoic acid (3,6-DCSA) is the penultimate intermediate in the synthesis of dicamba. Existing dicamba manufacturing routes utilize a high temperature, high pressure Kolbe-Schmitt carboxylation to prepare 3,6-DCSA. Described in this Letter is a new, non-Kolbe-Schmitt process to prepare 3,6-DCSA from salicylic acid in four chemical steps.
Process for preparing esters of 3,5,6-trichlorosalicyclic acid
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, (2008/06/13)
An improved process for the synthesis of esters of 3,5,6-trichlorosalicylic acid in quantitative yield comprises reacting the acid with an alcohol under distillation conditions in the presence of a titanium ester or chelate catalyst, whereby byproduct ether formation from the alcohol is suppressed. The process is especially applicable to a process by which salicylic acid is chlorinated first in concentrated sulfuric acid and then with iodine catalyst to make the trichlorosalicylic acid which is extracted and then reacted with an alcohol and a titanium catalyst to make the ester.
Processes for preparing 3,5,6-trichlorosalicylic acid and esters thereof
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, (2008/06/13)
An improved single-pot process for synthesis of 3,5,6-trichlorosalicylic acid and esters thereof is described. Salicylic acid is chlorinated first in concentrated sulfuric acid and then with iodine catalyst to make the trichlorosalicylic acid which is extracted and then reacted with an alcohol to make the ester.