Anions from

Fig. V-11. Electrocapillary curves (a) adsorption of anions (from Ref. 113) (b) absorption of cations (from Ref. 6) (c) electrocapillary curves for -pentanoic acid in QAN HCIO4. Solute activities from top to bottom are 0, 0.04761, 0.09096, 0.1666, and 0.500 (from Ref. 112).

Quaternary ammonium salts catalyze the reaction between an anion and an organic substrate by transfemng the anion from the aqueous phase where it cannot contact the substrate to the organic phase In the example just cited the first step occurs m the... 

Quaternary ammonium salts compounds of the type R4N" X find application m a technique called phase transfer catalysis A small amount of a quaternary ammonium salt promotes the transfer of an anion from aqueous solution where it is highly solvated to an organic solvent where it is much less solvated and much more reactive... 

DeioniZa.tlon, The removal of cations and anions from water and replacement of them with hydrogen and hydroxide ions is called deionization. The completeness of the ionic removal is dependent on resin selection, design of the system, operating conditions, and the quaUty of treated water required. In general, systems become more complex as quaUty requirements increase. 

The idea of kinetic versus thermodynamic control can be illustrated by discussing briefly the case of formation of enolate anions from unsymmetrical ketones. This is a very important matter for synthesis and will be discussed more fully in Chapter 1 of Part B. Most ketones, highly symmetric ones being the exception, can give rise to more than one enolate. Many studies have shown tiiat the ratio among the possible enolates that are formed depends on the reaction conditions. This can be illustrated for the case of 3-methyl-2-butanone. If the base chosen is a strong, sterically hindered one and the solvent is aptotic, the major enolate formed is 3. If a protic solvent is used or if a weaker base (one comparable in basicity to the ketone enolate) is used, the dominant enolate is 2. Enolate 3 is the kinetic enolate whereas 2 is the thermodynamically favored enolate. 

Fig. 12.2. EPR spectra of small organic free radicals, (a) Spectrum of the benzene radical anion. [From J. R. Bolton, Mol. Phys. 6 219 (1963). Reproduced by permission of Taylor and Francis, Ltd.] (b) Spectrum of the ethyl radical. [From R. W. Fessenden and R. H. Schuler, J. Chem. Phys. 33 935 (1960) J. Chem. Phys. 39 2147 (1963). Reproduced by permission of the American Institute of Physics.]...

Bromination of the enolate anion from the reaction of 3j -acetoxypregna-5,16-dien-20-one (1) with methylmagnesium bromide in the presence of cuprous chloride affords (after treatment with sodium iodide to dehalo-genate any 5,6-dibromide) a mixture of 17a-bromo- and 17)5-bromo-16a-methyl compounds (11) and (12) in a ratio 9 1. The 17a-iodides can be obtained in an analogous reaction. 

Dehydration of prednisolone acetate (175b) yields the corresponding 9,11 olefin. As a variation on the chemistry we have seen previously, this olefin is allowed to react with chlorine in the presence of lithium chloride. If this addition is assumed to proceed by the customary mechanism, the first intermediate should be the 9a,11a-chioronium ion. Axial attack by chloride anion from the 110 position will lead to the observed stereochemistry of the product dichlorisone (240). ... 

Incorporation of a carbonyl group into the alkyl side chain also proved compatible with biologic activity. The key intermediate (76) is obtainable by Michael addition of the anion from diethyl malonate to methylvinyl ketone followed by ketalization with ethylene glycol. Condensation of 76 with hydrazobenzene leads to the pyrazolodione hydrolysis of the ketal group affords ketasone (78). ... 

Attachment of a basic amino group to the side chain leads to a compound with antiparkinsonian activity. Alkylation of the carbanion from phenylacetonitrile with 2-chlorotriethylamine affords the product, 36. Conjugate addition of the anion from this to acrylonitrile gives the glutarodinitrile (37). Partial hydrolysis of this in a mixture of sulfuric and acetic acid leads to phenglutarimide (38). ... 

Alkylation of the anion from diethyl butylmalonate with... 

A not uncommon side effect observed with morphine and some of the other narcotic analgesics is constipation due to decreased motility of the gastrointestinal tract. It proved possible to so modify pethidine as to retain the side effect at the expense of analgesic activity. Relief of diarrhea, it will be realized, is a far from trivial indication. Alkylation of the anion from diphenylacetonitrile (95) with ethylene dibromide gives the intermediate, 96. Alkylation of normeperidine (81) with that halide... 

Reaction of pyroc techol with epichlorohydrin in the presence of base affords the benzodioxan derivative, 136, (The reaction may well involve initial displacement of halogen by phenoxide followed by opening of the oxirane by the anion from the second phenolic group.) Treatment of the alcohol with thio-nyl chloride gives the corresponding chloro compound (137). Displacement of halogen by means of diethylamine affords piper-oxan (138), a compound with a-sympathetic blocking activity. 

Fusion of an all cyclic ring onto the piperidine so as to form a perhydroisoquinoline is apparently consistent with analgesic activity. Synthesis of this agent, ciprefadol (68), starts with the Michael addition of the anion from cyclohexanone 56 onto acrylonitrile (57). Saponification of the nitrile to the corresponding acid ( ) followed by Curtius rearrangement leads to isocyanate Acid... 

A fully unsaturated tricyclic indole derivative serves as the aromatic moiety for a nonsteroid antiinflammatory agent. Preparation of this compound starts with the Michael addition of the anion from methyl diethylmalonate to cyclohexanone. The product (32) is then hydrolyzed and decarboxylated to give ketoester 33. Fischer condensation with p-chlorophenylhydrazine leads to the indole This is then esterified (35) and dehydrogenated to the carbazole 36. Saponification leads... 

An isoindol1 none moiety forms part of the aromatic moiety of yet another antiinflammatory propionic acid derivative. Carboxylation of the anion from -nitro-ethylbenzene (45) leads directly to the propionic acid (46). Reduction of the nitro group followed by condensation of the resulting aniline (47) with phthalic anhydride affords the corresponding phthalimide (48). Treatment of that intermediate with zinc in acetic acid interestingly results in reduction of only one of the carbonyl groups to afford the isoindolone. There is thus obtained indoprofen (49). ... 

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