117995-12-7

Upstream product

• 38560-96-2 2-chloro-1,3-dimethyl-5-nitro-benzene 
• 140-29-4 phenylacetonitrile 
• 87-62-7 2,6-dimethylaniline 
• 294853-97-7 N-(4-amino-2,6-dimethylphenyl)-4-methylbenzenesulfonamide 
• 4703-15-5 N-(2,6-dimethylphenyl)-4-methylbenzenesulfonamide 
• 16947-63-0 2,6-dimethyl-4-nitroaniline 

Downstream Products

• 685507-24-8 (2,6-dimethyl-4-nitrophenyl)phenylcyanomethane-d 

Relevant academic research and scientific papers

Kinetic study of the proton transfer reaction between (2,6-dialkyl-4- nitrophenyl)phenylcyanomethanes and MTBD in acetonitrile

Three (2,6-dialkyl-4-nitrophenyl)phenylcyanomethanes (alkyl=Me-1, Et-2, i-Pr-3) have been synthesized and used in kinetic studies of proton abstraction by strong MTBD base in acetonitrile. These carbon acids: 1, 2 and 3 revealed in acetonitrile similar strength, having pKa=25.78, 25.94, 26.19, respectively. The fastest reaction has been observed for 1 kH 25°=141.2dm3mol-1s-1 and the slowest for 2 kH25°=65.9dm3mol -1s-1, while for 3 was close to diethyl derivative k H25°=67.9dm3mol-1s -1. The values of primary deuterium kinetic isotope effects k H/kD are moderate and not sensitive to the bulk of alkyl substituent, ranging from 11 to 16 for 1 and 12 to 13 for 3, at the temperature range 10-35°C. The relation between acidity constants of C-acids and kinetic and thermodynamic parameters are discussed in terms of stereoelectronic influence of alkyls on charge distribution between 4-nitrophenyl and cyano substituents. The observed kinetics reflect superposition of the properties of substituents, including ortho-alkyls and solvation effect on the transition state (TS) in acetonitrile. The general view is that the TS comes early along the reaction path. The possible structure of the TS and the general discussion of the mechanism are given.

PROTON TRANSFER REACTIONS BETWEEN ORTHO-METHYL SUBSTITUTED DERIVATIVES OF 4-NITROPHENYLPHENYLCYANOMETHANE AND NITROGEN BASES IN ACETONITRILE SOLVENT

Equilibrium constants, rate constants, primary deuterium isotope effects, and activation parameters have been measured for the proton transfer reactions in acetonitrile solvent of 4-nitrophenylphenylcyanomethane and 2-methyl-4-nitrophenylphenylcyanomethane with tetramethylguanidine base and for the reactions of 2-methyl-4-nitrophenylphenylcyanomethane and 2,6-dimethyl-4-nitrophenylphenylcaynomethane with 1,5-diazabicycloundec-7-ene base.Introduction of the ortho-methyl groups in the substrate molecule caused significant reductions in the equilibrium and the rate constants.The expected rise in the kinetic primary deuterium isotope effect was not observed when the first ortho-methyl group was introduced, but a 20percent increase did accompany the introduction of the second ortho-methyl group.Enthalpy of activation measurements indicated that there was no increase in the proton tunnelling contribution to the isotope effect when the amount of steric hindrance is increased with ortho-methyl groups.