Abstract: 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.

Abstract: Monoacetals of aromatic diketones in which the acetal group is derived from primary mono- or dialkohols are useful as sensitizers in the photochemical polymerization or photochemical crosslinking of polymers. They are prepared from the diketones (benzils) by reaction with sulfites. The sulfites and the benzils may be formed immediately before the reaction in the same vessel without isolating these compounds. Most of the benzil monoacetals are new compounds.