Efficient and simple methods for the introduction of the sulfonyl, acyl and alkyl protecting groups on the nitrogen of indole and its derivatives

Article abstract of DOI:10.1016/S0040-4020(98)00865-5

The benzenesulfonylation, acetylation, methylation and benzylation at the 1 position of indole and its derivatives with bases such as NaOH, KOH and NEt₃ are presented. By using weaker bases than the traditional ones (BuLi, NaNH₂, etc.), the process is simpler, more general and leads to the products in 80-100% yields. The chemoselectivity in compounds bearing more than one nitrogen is also demonstrated.