Photolytic decomposition of indapamide

Photolytic decomposition of indapamide (I) in nitrogen-flushed methanol yields 3-sulfamoyl-4-chlorobenzamide (II), 2-methylindoline (III), semicarbazide (IV), and 1-(N-formamido)-2-methylindoline (V); in oxygen-flushed methanol, II--V, 1-aminocarboxymethyl-2-methylindoline (VI), 3-sulfamoyl-4-chlorobenzoic acid (VII), methyl-3-sulfamoyl-4-chlorobenzoate (VIII), and 2-(N-acetamido)-benzoic acid (IX) are formed. A comparison is made with thermal decomposition of I.