Nonsteroidal antiinflammatory agents. 2. Synthesis and biological activity of 2-chloroindolecarboxylic acids

The Vilsmeier and the Arndt-Eistert reactions have been employed for the synthesis of 1-phenyl-2-chloroindole-3-acetic acid (4). The antiinflammatory activity of 2-chloroindole-3-carboxylic acid (1), 1- methyl-2-chloroindole-3-carboxylic acid (2), 1-phenyl-2-chloroindole-3-carboxylic acid (3), and 4 was compared with the activity of indomethacin in the carrageenin rat edema. The best results are given by compounds 1 and 2 bearing H or CH3 at position 1 and COOH at position 3.