N-Phenylanthranilic acids, such as mefenamic acid, are important nonsteroidal anti-inflammatory drugs (NSAIDs) [ 1 1. Baures , PW ; Oza , VB ; Peterson , SA ; Kelly , JK Synthesis and evaluation of inhibitors of transthyretin amyloid formation based on the nonsteroidal anti-inflammatory drug, flufenamic acid . Bioorg. Med. Chem. 1999 , 7 , 1339 – 1347 . [CrossRef], [PubMed] View all references ] and crucial intermediates for the synthesis of acridones and acridines, ...