A strategy to avoid anomalous O-alkylation of 4-hydroxyindole by diethyl bromomalonate

✍ Scribed by George Papageorgiou; John E. T. Corrie

• Book ID: 102344883
• Publisher: Journal of Heterocyclic Chemistry
• Year: 2005
• Tongue: English
• Weight: 69 KB
• Volume: 42
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570420610

✦ Synopsis

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-bromomalonate 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.