2-Trifluoroacetyl aminoindoles as useful intermediates for the preparation of 2-acylamino indoles

A three-step method was developed to convert N-1 unprotected 3-substituted indoles to 3-substituted 2-acylaminoindoles. Established indole chlorination chemistry was employed to generate stable 2-trifluoroacetylamino indoles, which were subsequently deprotected and selectively acylated.