40567-33-7Relevant academic research and scientific papers
Process development for a herbicide intermediate via catalytic carboxylation of an aromatic diazonium compound
Siegrist, Urs,Rapold, Thomas,Blaser, Hans-Ulrich
, p. 429 - 431 (2003)
A laboratory process is described for the preparation of 2-sulfo-4-methoxybenzoic acid (SMBA) via diazotization of 2-amino-4-methoxy-sulfonic acid followed by Pd-catalyzed carbonylation in the presence of water. The most important process parameters were the catalyst precursor and water content. Both a two-step procedure using isolated diazonium compound as well as a one-pot reaction proved to be feasible. A yield of > 95% SMBA was obtained after 3-4 h, using 1 mol % PdCl2 at 8 bar and 60°C. This is the first technically feasible catalytic carbonylation of an arene diazonium compound.
Process for the preparation of aromatic O-sulfocarboxylic acids and sulfonylureas
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, (2008/06/13)
The invention relates to a process for the prepn of ortho-sulfocarboxylic acids, which comprises: a) in a first reaction step, diazotizing an aromatic o-aminosulfonic acid in the presence of an acid and nitrite in water, in an organic solvent or in a mixture thereof, to an o-diazonium sulfonate, and, b) in a second reaction step, reacting the o-diazonium sulfonate in the presence of a palladium catalyst in water, in an organic solvent or in a mixture thereof, with carbon monoxide, under overpressure, to an aromatic o-sulfocarboxylic acid. The invention also relates to a process for the preparation of sulfonylureas using o-sulfocarboxylic acids as intermediates. Thus, 4-methoxyaniline-2-sulfonic acid was diazotized and treated with CO to give 97% 4-methoxybenzoic acid 2-sulfonic acid.
