Ethyl methyl sulphone

Hypobromite has also been used as a sulphoxide oxidant. In this case, as with hypochlorite, multi-halogenated species are usually found. Thus, treatment of ethyl methyl sulphone with a basic aqueous hypobromite solution at 45 °C yielded the product shown in equation (37) in high yield97. In the presence of a-carboxylate groups, C—C bond cleavage occurs96 (equation 38). 

Table 3.5.2 Compilation of the most important secondary battery technologies. Energy densities compiled from various manufacturers data sheets and references [4,7-9] (EC/DMC, ethylene carbonate/dimethyl carbonate EMS (ethyl methyl sulphone)). 

Ethyl methyl sulphone CH3SO2-C2H5 68.9 + 2 288.3 + 8.4 Derived from AfH° in ref. 1986PED/NAY... 

Grow cells on enriched media containing the mutagen A-methyl-N, -nitro-Ar-nitrosoguanidine (MNNG) at 0.5/ig/ml or ethyl methane sulphonate (EMS) at 200/tg/ml for 16 h. 

Brosylate/tosylate rate ratios can be considered in the broader context of reaction series in which the substituents (Z) may be a wide range of meta- and para-substituted benzene derivatives. Hammett p values for thirty such solvolytic reaction series have been tabulated23, the highest observed p values are ca 1.8, for ethanolyses of 1- and 2-adamantyl sulphonates. Dependence on the alkyl group (R) is shown by the decrease in p to 1.55 for ethanolyses of i-propyl and to 1.3 for ethyl and methyl sulphonates. Lower p values (and lower OBs/OTs rate ratios—Table 3) are observed for more strongly hydrogen-bonding solvents. 

To 2-methylphenol in aq. NaOH at 5-10° ethyl fluoro-sulphonate added with vigorous stirring and mixture heatedat 40° for 0.5h., to give 2-methylphenyl methyl ether. 

Mercaptans — Sulpho compounds — Sodium isethionate — Methyl-sulphuric acid—Potassium-trichlorrmethyl sulphate — Potassium-trichlor-methyl sulphonate — Ethyl-sulphuric acid—Potassium-isoamyl sulphate—Potassium xanthate—Dimethyl-dithiocarbamic acid.47 49... 

Electron Diffraction.—Among completed electron-diffraction studies are ethyl methyl sulphide, chloromethyl methyl sulphide, methyl phenyl sulphide, di-(2-pyridyl) sulphide, sulphones, sulphoxides and sulphones, and trifluoro-methanesulphonyl chloride. A number of precise analyses of gas-phase conformational equilibria have emerged. Methyl ethyl sulphide shows a preference for the gauche conformation rather than for the trans form. ... 

Potassium Leiuene sulphonate, 177 Potassium ethyl sulphate, 50 Potassium methyl sulphate, 50 Preparations, general remarks, 47 Pressure tube, glass, 24, 78 furnace, 24 metal, 227... 

However, in an intriguing reaction promoted by the para-nitro groups of the aryl-sulphone (1) (Scheme 6.25), the initial Michael adduct derived from acrylic esters produces the diarylpropanoic esters (2), together with the diesters (3) (from methyl or ethyl acrylate) [39]. A similar addition-rearrangement reaction has been observed with l-aryl-2-(4-nitrobenzenesulphonyl)ethanones [40]. Additionally, reaction of the sulphonylethanone with two equivalents of the acrylic ester produces a 4-hydroxy-1,4-diarylcyclohexane-1,3-dicarboxylate. 

Thus, condensation with ethyl 4-bromo-3-methyl-2-butenoate (2E/2Z 50/50) provided the sulphone-ester, as a mixture of isomers (13 /13Z 50/50). Elimination to the ethyl 9-methylene-retinoate (2E/2Z 50/50) was done by treating the crude mixture with EtONa in cyclohexane, Fig. (42). 

Deprotection is effected in the case of methyl or ethyl esters by hydrolysis, usually under basic conditions (Section 9.6.17, p. 1266). t-Butyl esters are de-protected by mild acidic conditions, for example, formic acid at room temperature,159 toluene-p-sulphonic acid in benzene solution, or hydrogen bromide in acetic acid at 10°C.160... 

Dissolve 2-3 g of methyl toluene-p-sulphonate in 10 ml of dry toluene, add 1 g of the amine and boil the mixture for 20-30 minutes. Cool, and filter the precipitated quaternary salt. Recrystallise by dissolving the solid in the minimum volume of boling ethanol and then adding ethyl acetate until crystallisation commences. Filter the cold mixture, dry rapidly on a porous plate and determine the m.p. immediately. 

Base-catalyzed condensation of cyanothioacetamide with ethyl / -(ethoxy-methylene)acetoacetate furnished (127), which was quantitatively 5-methylated to yield (128). Ester reduction and alcohol protection generated (129), which was oxidized to the corresponding sulphone with mcpba. Guanidine cycli-zation to (130) and deprotection then afforded (131), identical in all respects with material prepared by the previously described ring-transformation reaction. 

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