Tetra salts

Lead tetraacetate (0.25 mol) and 1 mol of a carboxylic acid were heated together at 60-80°C, and the acetic acid was distilled at 10 mmHg pressure as it formed. The product was pure enough for further reactions without other treatment. When the lead tetra-salt melted > 80-100°C, a solvent, such as 1,1,2,2-tetrachloroethane, o-dichlorobenzene, or mineral oil, was used to prevent caking and local superheating of the product. 

Lead tetra-salts of fatty acids alkylate pyridine, giving 2- and 4-alkyl-pyridines 020 With red lead in acetic acid, 3-butylpyridine underwent mono-, di- and poly-methylation. The monomethyl compounds represented about 20 per cent of the product, and in these, substitution was distributed i as shown in (123). 

Compton R G, Spaokman R A, Wellington R G, Green M L H and Turner J 1992 A Cgg modified eleotrode. Eleotroehemioal formation of tetra-butylammonium salts of Cgg anions J. Electroanal. Chem. Interfacial... 

Place a mixture of 125 ml. of A.R. benzene and 32 -5 g. of di-re-butyl d-tartrate (1) in a 500 ml. three-uccked flask, equipped with a Hershberg stirrer (Section 11,7) and a thermometer. Stir the mixture rapidly and add 58 g. of lead tetra-acetate (Section 11,50,15) in small portions over a period of 20 minutes whilst maintaining the temperature below 30° by occasional cooling with cold water. Continue the stirring for a further 60 minutes. Separate the salts by suction filtration and wash with two... 

Iron hahdes react with haHde salts to afford anionic haHde complexes. Because kon(III) is a hard acid, the complexes that it forms are most stable with F and decrease ki both coordination number and stabiHty with heavier haHdes. No stable F complexes are known. [FeF (H20)] is the predominant kon fluoride species ki aqueous solution. The [FeF ] ion can be prepared ki fused salts. Whereas six-coordinate [FeCy is known, four-coordinate complexes are favored for chloride. Salts of tetrahedral [FeCfy] can be isolated if large cations such as tetraphenfyarsonium or tetra alkylammonium are used. [FeBrJ is known but is thermally unstable and disproportionates to kon(II) and bromine. Complex anions of kon(II) hahdes are less common. [FeCfy] has been obtained from FeCfy by reaction with alkaH metal chlorides ki the melt or with tetraethyl ammonium chloride ki deoxygenated ethanol. 

The tetra alkyl amm onium salts of [B Hg] , formed by ion-exchange reactions, have proven to be useful synthetic reagents because of their thermal and air stabihties. The stmcture of the [B Hg] ion has been determined by an x-ray study (66) and shown to have the 2013 styx stmcture, C2 symmetry. Mechanisms for the formation of this ion have been proposed (67). Tetraborane(lO) can be easily obtained from salts of [B Hg] (eq. 9). 

Catalyst Cation. The logarithms of extraction constants for symmetrical tetra- -alkylammonium salts (log rise by ca 0.54 per added C atom. Although absolute numerical values for extraction coefficients are vastly different in various solvents and for various anions, this relation holds as a first approximation for most solvent—water combinations tested and for many anions. It is important to note, however, that the lipophilicity of phenyl and benzyl groups carrying ammonium salts is much lower than the number of C atoms might suggest. Benzyl is extracted between / -propyl and -butyl. The extraction constants of tetra- -butylammonium salts are about 140 times larger than the constants for tetra- -propylammonium salts of the same anion in the same solvent—water system. 

Benzyltriethylammonium chloride [56-37-1] is the most widely used catalyst under strongly basic conditions. Methyltrioctylammonium chloride [5137-55-3] (Ahquat 336, Adogen 464) is probably the least expensive catalyst. Others of high activity and moderate price are tetra- -butylammonium chloride [1112-67-0] bromide [1643-19-2] hydrogen sulfate [32503-27-8], tetra- -butylphosphonium chloride [2304-30-5], and other phosphonium salts of a similar number of C atoms. Many other onium salts can also be utilized. 

Competitive Extraetion of Anions. The successful extraction of the necessary anion into the organic phase is cmcial for PTC. Often three anions compete for the catalyst cation the one that is to react, the one formed in the reaction, and the one brought in originally with the catalyst. Table 1 hsts the widely differing values of tetra-rr-butylammonium salts. The big difference in the halide series is noteworthy and preparatively important. Hydroxide is 10 times mote difficult to extract than chloride (11) and the divalent and trivalent anions and PO " are stiU more hydrophilic. Thus... 

Cinnolin-3(2//)-one (7) is methylated with diazomethane or methyl sulfate to give 2-methylcinnolin-3(2H)-one. In a similar manner, benzylation with benzyl chloride, cyanoethylation with acrylonitrile in the presence of benzyltrimethylammonium hydroxide and glucosidation with tetra-O-acetyl-a-o-glucopyranosyl bromide in the presence of a base affords the corresponding 2-substituted cinnolin-3(2//)-ones. However, glucosidation of the silver salt of cinnolin-3(2//)-one produces the corresponding O-substituted compound. 

No attempt should be made to purify perchlorates, except for ammonium, alkali metal and alkaline earth salts which, in water or aqueous alcoholic solutions are insensitive to heat or shock. Note that perchlorates react relatively slowly in aqueous organic solvents, but as the water is removed there is an increased possibility of an explosion. Perchlorates, often used in non-aqueous solvents, are explosive in the presence of even small amounts of organic compounds when heated. Hence stringent care should be taken when purifying perchlorates, and direct flame and infrared lamps should be avoided. Tetra-alkylammonium perchlorates should be dried below 50° under vacuum (and protection). Only very small amounts of such materials should be prepared, and stored, at any one time. 

Pyrenesulfonic acid [26651-23-0] M 202.2, m >350 , pKgj, <0. Crystd from EtOH/water. The tetra-Na salt cryst from H2O and the sulfonyl chloride has m 120°(dec). [Vollmann et al. Justus Liebigs Ann Ghent 531 32 1937 and Justus Liebigs Ann Ghent 540 189 1939.]... 

Chlorazol Sky Blue FF 6,6 -[(3,3 -dimethoxy[l,l -biphenyl]-4,4 -diyl)bis(azo)bis(4-amino-5-hydroxy-l,3-naphthylenedisulfonic acid) tetra-Na salt [2610-05-1 ] M 996.9, m... 

In a 250 ml Erlenmeyer flask covered with aluminum foil, 14.3 g (0.0381 mole) of 17a-acetoxy-3j5-hydroxypregn-5-en-20-one is mixed with 50 ml of tetra-hydrofuran, 7 ml ca. 0.076 mole) of dihydropyran, and 0.15 g of p-toluene-sulfonic acid monohydrate. The mixture is warmed to 40 + 5° where upon the steroid dissolves rapidly. The mixture is kept for 45 min and 1 ml of tetra-methylguanidine is added to neutralize the catalyst. Water (100 ml) is added and the organic solvent is removed using a rotary vacuum evaporator. The solid is taken up in ether, the solution is washed with water and saturated salt solution, dried over sodium sulfate, and then treated with Darco and filtered. Removal of the solvent followed by drying at 0.2 mm for 1 hr affords 18.4 g (theory is 17.5 g) of solid having an odor of dihydropyran. The infrared spectrum contains no hydroxyl bands and the crude material is not further purified. This compound has not been described in the literature. 

Shandong Changyi Salt Chemicals (China) TETRA Technologies Tosoh Coip. (Japan)... 

Lithium aluminum hydride reduction of pyridinium salts is very similar to sodium horohydride reduction and gives similar products, but the ratio of 1,2- and 1,4-dihydro- or tetrahydropyridines differs considerably (5). Isoquinolinium salts are reduced hy sodium borohydride or lithium aluminum hydride in a manner identical to pyridinium salts (5). Quino-linium salts are reduced by sodium borohydride to give primarily tetra-hydroquinolines (72) as shown by the conversion of 33 to 34 and 35. When lithium aluminum hydride is used, the product is usually the dihydroquinoline (73) as shown in the conversion of 36 to 37 and 38. 

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