Three‐Component Synthesis of 2‐Heteroaryl ‐3‐hydroxybenzo[ b ]‐thiophenes under Transition‐Metal‐Free Conditions

Main observation and conclusion A convenient synthetic route to 2‐heteroaryl‐3‐hydroxybenzo[ b ]thiophene derivatives via K 2 CO 3 ‐promoted multicomponent cyclization between o ‐halogenated benzaldehyde, 2‐methylquinolines and sulfur powder has been demonstrated. This reaction is performed smoothly under simple conditions to give the corresponding products in moderate to good yields. The resultant 3‐hydroxybenzo[ b ]thiophenes have been proved...