P-methoxybenzyl group as a protecting group of the nitrogen in indole derivatives: Deprotection by DDQ or trifluoroacetic acid
Deprotection of 9-p-methoxybenzylcarbazole with DDQ gave a carbazole. However, methyl 1-p-methoxybenzylindole-2-carboxylate and dimethyl 1-p-methoxybenzyl-2,3-indoledicarboxylate were treated with TFA to yield the corresponding methyl indole-2-carboxylate and dimethyl indole-2,3-dicarboxylate.