1-Methylpyrrole was reacted with a number of different types of N-chloro derivatives, and (σ-substitution was observed only with N-chloroimides. It is proposed that there is a qualitative relationship between the pKaof the N-chloro precursor and the reaction path. The reaction of 1-substituted pyrroles (CH3, C6H5, C6H6CH2, CH3CO0, (CH3)3C, CH2—CHCH2, (C6H6)3C) with N-chlorosuccinimide in CHCl3/NaHCO3indicated that (σ-substitution was very sensitive to electronic factors, e.g. no reaction was observed with 1-acetylpyrrole. It was not as sensitive to steric effects, and only with 1-tritylpyrrole was σ-substitution not observed. Only chlorination was observed with pyrrole itself.
All Science Journal Classification (ASJC) codes
- Organic Chemistry