[chemical substances]
   compounds
     Class amides [RkE(=O)l(OH)m (l≠0; ≥1 (OH):=(NR2))]
       Class primary amides [acyl-NR2]
         821.1 Class carboxamides [RC(=O)NR2]
         821.1 Class sulfonamides [RS(=O)2NR2] - amides of sulfonic acids