Salt substitute, sodium obtaining

Thioetherification of PECH is feasibly performed in DA-solvents as already described in the patent (20J. For example, the highest substitution was obtained by the reaction of P(ECH-EO)(1 1 copolymer of epichloro-hydrin and ethylene oxide) and equimolar thiophenoxide in HMPA at 100°C for 10 h as DS 83% for sodium and 93% for potassium salts. The DS in our nucleophilic substitution was estimated by the elemental analysis as well as the titration of liberated chloride ion with mercuric nitrate (21). In the latter method, reacted medium was pretreated with hydrogen peroxide when the reductive nucleophiles which can react with mercuric ion were used. As described before for PVC, thiolation was also achieved conveniently with iso-thiuronium salt followed by alkaline hydrolysis without the direct use of ill-smelling thiolate. The thiolated PECH obtained are rubbery solids, soluble in toluene, methylene chloride, ethyl methyl ketone and DMF and insoluble in water, acetone, dioxane and methanol. 

The reaction of o,p-dicyano-a-phenylsulphonyl cumene with sodium thiophenolate in DMF produces o,p-dicyano-a-phenylthiocumene. A product of similar substitution is obtained with the potassium salt of diethyl malonate as a reactant (Komblum and Fifolt 1980 Scheme 4.1). 

An early report of the beneficial influence of 1,1-diphenylethylene (DPE) on the yields of alkylaryl ether obtained in the reaction of diaryliodonium salts with sodium alkoxides showed that radical chain reactions compete efficiently with the 0-arylation reaction. By contrast, addition of diphenylpicrylhydrazyl, a stable free radical species, had no significant influence on the yields of products obtained in e absence of additives. In this case, the 0-arylation reaction was considered to be a direct nucleophilic aromatic substitution reaction, without the involvement of any transient covalent intermediate. (Table 2.11)... 

The formation of a stable 1,2-oxaphospholan from the sodium salt of benzoin and triphenylvinylphosphonium bromide has been extended to substituted vinylphosphonium salts, diastereoisomers being obtained in some cases. 

The 6-0-benzyl protected dienes 4a and 4P were prepared from the known (10) 1,2-O-isopropylidene-a-D-glucofuranose (Scheme 3). In fhis case, evidence for the intermediate formation of aldehyde 23a in the Wittig reaction conducted at room temperature was obtained by comparison with an authentic sample of aldehyde 23a obtained directly from compound 21 (a + P) using P-tosyloxy acrolein prepaid in situ from the sodium salt of malonaldehyde and tosyl chloride in THF. Finally, the methyl substituted derivatives 5a and SP were prepared as for the parent dienes 2a and 2p according to Scheme 1 using the corresponding 2-methyl substituted sodium salt of malonaldehyde (72). 

Elie Seignette (La Rochelle 1632-1698) in making soluble tartar (potassium tartrate) from tartar (potassium hydrogen tartrate) substituted soda (sodium carbonate) for potash (potassium carbonate) and obtained a new salt, potassium sodium tartrate, now called Rochelle salt or (on the Continent) Seig-nette s salt. This he called sel polychreste and after its discovery in 1648-1660 (probably 1655) brother Jehan (Rochelle 1623-1663), who kept the... 

The Sandmeyer reaction may also be applied to the preparation of nitriles. The solution of the diazonium salt is added to a solution of cuprous cyanide in excess of sodium or potassium cyanide solution (sometimes improved yields are obtained by substituting nickel cyanide for cuprous cyanide), for example CH3 CH, CH3... 

Acrylonitrile reacts with the sodium salt of 4.5-dimethvl-A-4-thiazoline-2-thione (73J (R4 = R5 = Me) to yield 3-(2-cyanoethyl)-4.5-dimethyl-A-4-thiazoline-2-thione (74) (R4 = R, = Me) (Scheme 35 (160). Humphlett s studies of this reaction showed that the size of the R4 substituent is a determinant factor for the S versus N ratio (161. 162). If R4 == H, 100% of the N-substituted product (74) is obtained this drops to 50% when R4 = methyl, and only the S-substituted product (75) is obtained when R4 = phenyl. The same trend is observed with various CH2 = CH-X (X = C00CH3. COCH3) reagents (149). The S/N ratio also depends on the electrophilic center for CH2 = CH-X systems thus S-reaction occurs predominantly with acrylonitrile, whereas N-substitution predominates with methvlvinvlketone (149). 

Properties. Thienamycin is isolated as a colorless, hygroscopic, zwitterionic soHd, although the majority of carbapenems have been obtained as sodium salts and, in the case of the sulfated olivanic acids, as disodium salts (12). Concentrated aqueous solutions of the carbapenems are generally unstable, particularly at low pH. AH the substituted natural products have characteristic uv absorption properties that are often used in assay procedures. The ir frequency of the P-lactam carbonyl is in the range 1760 1790 cm . ... 

Where X is Br or Q, the free acids may be obtained by acidification of the alkaline solution, but where X is I, the acids must be isolated as salts to avoid reduction of the arsonic acids by HI. Rather than using alkyl haUdes, alkyl or dialkyl sulfates or alkyl arenesulfonates can be used. Primary alkyl haUdes react rapidly and smoothly, secondary haUdes react only slowly, whereas tertiary haUdes do not give arsonic acids. AHyl haUdes undergo the Meyer reaction, but vinyl hahdes do not. Substituted alkyl haUdes can be used eg, ethylene chlorohydrin gives 2-hydroxyethylarsonic acid [65423-87-2], C2H2ASO4. Arsinic acids, R2AsO(OH), are also readily prepared by substituting an alkaU metal arsonite, RAs(OM)2, for sodium arsenite ... 

Substitution of chloropolymer is possible using a variety of nucleophiles. The most common are sodium salts of alcohols and phenols. Thermoplastics are obtained using a single substituent, whereas multiple substituents of sufficiently different size lead to elastomers (2). Liquid crystal behavior similar to polysHoxanes has been noted in most homopolymers. The homopolymer formed using trifluoroethanol as a substituent has received a fair amount of academic scmtiny (7). 

Polyphosphazenes sulfonates XIX with the anion covalently attached to the polymer are a new class of cation conductors that have been synthesized by Shriver [625]. They were obtained by reaction of Na0C2H4S03Na with an excess of polydichlorophosphazene in the presence of 15-crown-5, followed by the reaction of the partially substituted product with the sodium salt of poly(ethylene glycol methyl ether). The conductivity at 80 °C of the polymer with x=1.8, m=7.22 is 1.7x10 S cm This low conductivity can be attributed to an extensive ion pair formation between the sodium and sulfonate ions. 

With Roustan et al. using the sodium salt of the Hieber anion 76-Na, the procedure was improved by Xu and Zhou in 1987 when they introduced the corresponding shelf-stable tetrabutylammonium salt 76-[Bu4N] which is available from Fe(CO)5 78, NaN02 and Bu4NBr (Scheme 17) [61,62]. As well as discovered by Roustan they obtained the substitution products with an ipso-preference (Scheme 16) albeit in a significantly lower yield. In order to maintain the catalytic activity of the product, the reactions were performed under CO-gas atmosphere. 

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