In aqueous buffer at neutral pHs. 5, 6-dihydroxy-2-methylindole (2) is rapidly oxidised by the peroxidase/H2O2 system to give in the early phases a complex mixture of oligomers, the major of which were isolated as the O-acetyl derivatives. Five of these were formulated as the 3, 3′-biindolyl 3, the isomeric dimers 4–6 and trimer 9, arising by coupling of the indole ring at the nuclear positions, whereas the remaining ones were assigned structures 7–8, ...
