Synthesis of indole alkaloids arsindoline A, arsindoline B and their analogues in low melting mixture

Synthesis of newly isolated bis(indolyl)methane alkaloids arsindoline A, arsindoline B from a marine-derived bacterium strain CB101 and their analogues are reported using low melting l-(+)-tartaric acid-dimethyl urea mixture. The reaction is mild, non-toxic, and occurs in environmentally benign conditions. We also reported the synthesis of another alkaloid 2,2-bis(6-bromo-1H-indol-3-yl)ethanamine using low melting mixture.