A strategy to avoid anomalous<i>O</i>-alkylation of 4-hydroxyindole by diethyl bromomalonate
作者:George Papageorgiou、John E. T. Corrie
DOI:10.1002/jhet.5570420610
日期:2005.9
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
在标准条件下,用溴代丙二酸二乙酯(碳酸钾-丙酮)将4-羟基吲哚烷基化,得到预期的吲哚基氧基丙二酸酯3和异常的吲哚基氧基-2-溴-丙二酸酯4。取决于条件,两种产物的比例在4:1和1:2之间变化。通过碳苄氧基保护吲哚氮消除了异常产物的形成。