Arylsulfonylation of N-isobutylaniline and its derivatives: experimental study and quantum-chemical calculations

The kinetics of the reactions of benzene-substituted N-isobutylanilines 1a—h with 3-nitrobenzenesulfonyl chloride in propan-2-ol was studied at 298 K. To analyze the reactivities of compounds 1a—h in the arylsulfonylation reactions and substantiate the possible mechanism of these reactions, the geometric, electronic, and energy characteristics of the reagents and a series of model compounds were calculated by the semiempirical quantum-chemical AM1 and PM3 methods. The rate of arylsulfonylation of N-isobutylaniline and its derivatives increases directly proportional to the contributions of the s and p _z orbitals of the N atoms to HOMO of amine and of the S atoms to LUMO of sulfonyl chloride. The coefficients of these AOs can be considered as the reactivity indices of the reagents used for arylsulfonylation of substituted N-isobutylanilines with aromatic sulfonyl chlorides. It was proposed that the reaction under study is orbital-controlled.     

Synthesis of N-Isobutylanilines Substituted in the Benzene Ring and Their Reactivity in Arenesulfonylation

Secondary aliphatic-aromatic amines were synthesized by hydrogenative amination of aliphatic aldehydes with aromatic amines. The kinetics of arylsulfonation of the resulting alkylarylamines with benzenesulfonyl chloride and its monosubstituted derivatives in 2-propanol at 298 K were studied. The activation parameters of the reaction of ring-substituted N-isobutylanilines with 3-nitrobenzenesulfonyl chloride were determined.     

Effect of solvent on the kinetics of arylsulfonylation of N-alkylated anilines in a water-propan-2-ol system

The effect of the composition of a water-propan-2-ol solvent on the kinetics of arylsulfonylation of N-ethyl-, N-isopropyl-, and N-butylanilines with 3-nitrobenzenesulfonyl chloride at 298 K was studied. The reaction rate constant increases monotonically with an increase in the water fraction in the solvent from 5 to 30 wt.%. The apparent activation parameters of the reaction of N-butylaniline with 3-nitrobenzenesulfonyl chloride were calculated. No considerable changes in the activation parameters of the reaction were observed on going from pure propan-2-ol to a 10% aqueous solution, which indicates that the mechanism remains unchanged upon solvent change. Propan-2-ol with a water content of 5–30 wt.% can be used in the synthesis of arylsulfonylation products of the amines under study in 98–99% yield. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 937–939, June, 2006.     

Quantum-chemical simulation of acyclic and cyclic forms of glucose in ethanol

Equilibrium between acyclic and cyclic forms of glucose in ethanol has been simulated by quantum chemistry methods. The cyclic form prevails in the ethanolic solution. Solvation of glucose molecules is accompanied by additional structurization, the effect being more prominent in the case of the linear form.     

Study of the terminal interactions between Molecules of (4-n-butoxyphenyl)-N-(p-tolyl)methanimine

The energy of interaction between (4-n-butoxyphenyl)-N-(p-tolyl)methanimine molecules has been estimated and decomposed by Morokuma method. It has been shown that the intermolecular interaction energy is a function of both intermolecular distance and relative orientation. Terminal interactions have been found to be very weak.