Abstract Alkylation of 4-hydroxyindole with diethyl bromomalonate under standard conditions (potassium carbonate-acetone) gave the expected indolyloxymalonate ester 3 together with the anomalous indolyloxy-2-bro-momalonate 4. Depending on conditions, the ratio of the two products varied between 4: 1 and 1: 2. Protection of the indole nitrogen by a carbobenzyloxy group eliminated formation of the anomalous product.
