BROMINATION OF DIMETHYL 1-SUBSTITUTED INDOLE-2,3-DICARBOXYLATES

摘要

Treatment of dimethyl indole-2,3-dicarboxylate with pyridinium hydrobromide perbromide or bromine in the presence of Lewis acid gave dimethyl 5-bromoindole-2,3-dicarboxylate as the sole product.In a similar manner,dimethyl 1-benzyl-and l-benzenesulfonyl-indole-2,3-dicarboxylates provided a mixture of the corresponding 5-bromoindole and 6-bromoindole derivatives.However,methyl l-trifluoromethanesulfonylindole-2,3-dicarboxylate gave methyl 6-bromo-l-trifluorornethanesulfonylindole-2,3-dicarboxylate as a major product.