Demonstration of a mesomeric effect of the methylsulfonyl group. (Preliminary communication)

Abstract

It has been proved that the rnethylsulfonyl group can exert a (negative) mesomeric effect.In view of the fact that the present-day literature contains many discussions with respect to the problem whether the methylsulfonyl group has a (negative) mesomeric effect, it may be useful to publish, in a very provisional form, some results obtained in our laboratory during recent years.Our method OE attack consisted in the determination OC the reaction rate constants for the deacylation of acetylaminobenrene and certain of its derivatives in methyl alcoholic sodium methoxide I ) . HNAc

Mechanism of the basic methanolysis of benzanilides

“…Reaction via this transition state has been shown4 to have a low P2 value and pi would also be expected to be much smaller for protonation at the distant nitrogen than was experimentally observed. For example, = 1.05 (298°K) for the dissociation of substituted benzylammonium ions.8 In addition, the large rate enhancement observed at both ends of the reactivity scale on changing the solvent to 80% DMSO-methanol (a factor of 454 at 286.5°K for PhC0NMeC6H4N02-p and 330 at 373°K for PhCONMePh) is consistent with reaction by way of 4 but not 3 (in which a negligible solvent effect occurs).9…”

Chem-Bioinformatics and QSAR: A Review of QSAR Lacking Positive Hydrophobic Terms

“…Although we have nothing directly comparable to compare with eq 29, the following example is of interest. 27 Deacylation rate of X-C 6 H 4 NHCOMe with OMe (Table 27) 27 Nucleophilic displacement by CH 3 Oshows a similar dependence on electron withdrawal by substituents.…”

“…Recent elegant studies on the binding of cis-platinum 26 show that the chlorines are displaced in the binding process that leads to mutagenesis. Although we have nothing directly comparable to compare with eq 29, the following example is of interest …”

The Expansion of the Sulfur Outer Shell.

“…Kinetic evidence of the conjugative ability of the sulfonyl group is also available. This group has been found to activate the deacylation of acetanilides with an ability comparable to that of the cyano group (110).…”