New indole tritylation method

Synthesis and cytotoxic activity of 3-triarylmethylindoles. III. 3-[Diphenyl(pyridyl)methyl]indoles

“…Indole was alkylated by the heterosubstituted carbinols in the melt in the presence of zinc chloride under more forcing conditions than for the corresponding triphenyl derivatives. Thus, whereas indole was alkylated by triphenylcarbinol in approximately 1 min at 130 -136°C in quantitative yield [3], it was alkylated by the N-containing triarylcarbinols only at 200°C and higher (for Ia and Ib) with lower yields; for Ic, the reaction did not proceed at all under analogous conditions. Therefore, compounds Ic and II were prepared by first transforming the appropriate triarylcarbinols into the triarylmethylchlorides, which were then condensed with indole in boiling pyridine.…”