K2CO3-Promoted Highly Selective N-Hydroxymethylation of Indoles Under Metal- and Lewis Acid-Free Conditions

Inorganic base promoted highly selective N-hydroxymethylation of indole and its derivatives have been developed. It provided a simple method for the preparation of N-hydroxymethyl indoles with polyformaldehyde as reagents under the metal- and Lewis acid-free reaction conditions. The reaction proceeded smoothly using K₂CO₃ as base in 1,4-dioxane to produce the corresponding N-hydroxymethyl indoles with 62%->99% yields.