Aromatic Nucleophilic Substitution Reactions of Some 2-L-3-Nitro-5-X-thiophenes with Piperidine and Aniline in Methanol. Substituent Constants for the Thiophene System
The rate constants for the reactions of some 2-L-3-nitro-5-X-thiophenes 1-4 with aniline and of compounds (4) with piperidine in methanol have been measured at various temperatures.By using the data obtained in this work as well as previously available data sets, a series of optimized 'thiophene' ?τ values has been calculated.The susceptibility constants ρ(L) of the various sets have been analysed in the framework of the reactivity-selectivity principle.