Studies on Fused Indoles. I. Novel Synthesis of 4-Aminomethyltetrahydrothiopyrano [2, 3-b] indoles through a Thio-Claisen Rearrangement

Abstract

Two novel and simple methods for preparing 4-aminomethyl-2, 3, 4, 9-tetrahydrothiopyrano [2, 3-b] indoles are described. Both involve thio-Claisen rearrangements of indol-2-yl propargyl sulfides as a key step which affords thiopyrano [2, 3-b] indoles in good yields. Elaboration of these compounds led to fused tryptamine analogues which were found to have strong analgesic activity. The mechanism of this novel rearrangement is discussed.