Methyl p nitrobenzenesulfonate

Alunni, S., Pero, A., Reichenbach, G., Reactivity of ions and ion pairs in the nucleophilic substitution reaction on methyl p-nitrobenzenesulfonate. J. Chem. Soc., Perkin Trans., 21998, 1747-1750. 

SN2 reactions between methyl p-nitrobenzenesulfonate and halide ions and amines in several different ionic liquids have been investigated.76 The rates of reaction can be understood using the Hughes-Ingold rules77 if one considers the ion-ion interactions and ion-dipole interactions that occur with the ionic liquid solvent. Changing the ionic liquid solvent can reverse the relative reactivity of Cl-, Br-, and I- nucleophiles. 

Methyl p-Nitrobenzenesulfonate, p-Nitrobenzene-sulfonic acid methyl ester. C,HTNO,S mol wt 217.20. C 38.71%, H 3.25%, N 6.45%, O 36.83%, S 14.76%. Reagent for selective methylation or cysteine residues in chemical modification of proteins Nakagawa, Bender, J. dm. Chem. Sac, 91, 1566(1969). Procedure Heinrikson. Biochem. Bio-phys. Res. Common. 41, 967 (1970). Prepd by the general method of reacting p-nitrobenzenesulfony] chloride with alcohols. See Morgan, Cretcher, J. Am. Chem Soc. 70, 375 (1948). 

The large variation in polymerization rates among the various 2-oxazoline monomers has been exploited for the preparation of quasi-diblock copolymers, namely, gradient copolymers with a narrow and steep monomer gradient, by statistical copolymerization of selected monomer combinations exhibiting large differences in reactivity. Such a one-pot quasi-diblock copolymer synthesis was first demonstrated for the statistical copolymerization of 2-phenyl-2-oxazoline and a much less reactive 2-perfluoroalkyl-2-oxazoline [174]. This living CROP (in nitromethane at 120 °C initiated by methyl p-nitrobenzenesulfonate) revealed complete consumption of the 2-phenyl-2-oxazoline after 2 min with only minor incorporation of the fluorinated monomer. Continuation of the polymerization for another 40 h led to full conversion of the fluorinated monomer. The... 

Nucleophilic substitution reactions in ionic liquids have recently been the subject of both synthetic [33] and kinetics and mechanistic studies [34]. Ionic liquids may be efficient promoting media for nucleophilic displacement reactions and important information about the ionic liquid properties has been obtained from the study of these reactions. The kinetic investigation of bimolecular substitution reactions of the halides on methyl p-nitrobenzenesulfonate, recently carried out by Wdton et al. [34] in several ionic media characterized by the same anion, [Tf2N] , and different cations ([BMIM]+, [BMMIMJ+ and [BMPY]+) or by the same cation, [BMIM] and different anions ([BF4] , [PFs] , [SbF ] and [Tf2N] ), has shovrathat the halides nucleophilicities depend on the ionic liquid structure (Scheme 5.1-7). 

Scheme 5.1-7 Bimolecular substitution reaction of methyl p-nitrobenzenesulfonate with halides.

Scheme 5.1-8 Equilibrium between fully coordinated unavailable" chloride and a one face available chloride in the bimolecular substitution reaction of methyl p-nitrobenzenesulfonate with chloride.

Cationic movements are given as percentages of the anionic movement (about 10 cm) of p-nitrobenzenesulfonic acid on the same strip with 2,3,6-tri-O-methyl-D-glucose as non-migrating marker. The electrolyte solution was a 0.1 M solution of the metal acetate in 0.2 M acetic acid. 

Methionine sulfoximine phosphate, 26 iV-Methyl-iV-(2-p-azidophenylethyl)-norlevorphanol, 604, 606 Methylene blue, 563 2-Methyleneoxide- (1,3,5/4,6)-pentahy-droxycyclohexane, 369 3,10-Methylenetetrahydrofolate, 307 Methylketones, 199 -Methylketones, 135 iV-Methylmorpholine, 202, 203, 224 A -Methylmorpholine-HCl, 311 Methyl 4-nitrobenzenesulfonate, 537, 539... 

Kiprianov (1957) studied the relative rates of formation of quaternary salts of 2-methylbenzothiazole with methyl iodide, methyl sulfate, and methyl esters of sulfonic acids and p-nitrosulfonic acids. He found that the reaction with methyl 2-nitrobenzenesulfonate was six times faster than that with Me2S04, while the methyl esters of the 2,3- and 2,4-dinitrobenzenesulfonic acid reacted sixty times more rapidly than did Me2S04. Such esters afford a method for very mild alkylation of very weak bases (Kip>rianov Tolmachev 1957). 

Thio-L-rhamnofuranose (27) was obtained by triflate displacement at C-4 of the h-talo-configurated pyianose derivative (26) with KSCN in DMF and subsequent reduction of the thiocyanate group and acetolysis/deacetylation as indicated in Scheme S." When similar displacements were attempted with derivatives of methyl 6-deoxy-a-D-mannopyranoside, a 2 1 mixture of 4-thiocyano sugars (32) and (33) was produced from the dihydroxy-p-nitrobenzenesulfonate (28) in S2% combined yield however, compounds (29)-(31) underwent solvolysis and/or decomposition under the reaction conditirms. ... 

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