Studies on the acylation of 4-(2-aminoethylthio)-7-nitrobenzofurazan: the role of bases in promoting the formation of fluorescent S-acyl derivatives through S–N Smiles rearrangement

The acylation of 4-(2-aminoethylthio)-7-nitrobenzofurazan has been investigated. Depending on the use of the base, a competitive Smiles rearrangement occurs during the acylation step leading to the formation of N-acyl and/or fluorescent S-acyl derivatives. The acylating agent also affects the ratio of N/S acylated isomers.