Ipso nitration. Nitrodeformylation reactions in nitrothiophenealdehydes

Abstract

Abstract Nitration of 4‐nitro‐2‐thiophenealdehyde afforded 2,4‐dinitrothiophene and small quantities of 4,5‐dinitro‐2‐thiophenealdehyde; 5‐nitro‐2‐thiophenealdehyde gave instead 3,5‐dinitro‐2‐thiophenealdehyde as the main product and some 2,5‐dinitrothiophene. The two dinitrothiophenes form through a nitrodeformylation reaction which represents an interesting example of the nitration at an ipso position in a strongly deactivated substrate.