摘要 |
<p>1. A process for the preparation of 5-sulfamoyl-orthanilic acids of the formula I see diagramm : EP0047973,P5,F1 in which R denotes N-methylanilino, phenylsulfonyl, phenoxy, which is optionally substituted by Cl, CH3 or OCH3 , or alkyl sulfonyl or cycloalkylsulfonyl or cycloalkylalkylsulfonyl having up to 10 carbon atoms in each case, and Ar denotes phenyl or furyl, in the form of their salts, which comprises hydrogenating an aryl ester of the formula II see diagramm : EP0047973,P5,F2 in which Z denotes aryl, in a solvent which is stable to hydrogenation and with the addition of at least one equivalent of a base, in the presence of a palladium catalyst, until one mol equivalent of hydrogen has been absorbed.</p> |