Tetrachloroaluminic acid

Tetrachloroaluminic acid Carboxylic acid esters from carboxylic acids... 

Tetrachloroaluminic acid s. Aluminum chloride/ hydrogen chloride Tetrachloro-o-benzoquinone s. o Chloranil... 

Esterification at room temp, with tetrachloroaluminic acid ether complex has been described The alcoholysis of a-mono-alkylacetoacetates to the corresponding esters and alkyl acetates has been accomplished with excellent yields A new modification of the Curtius degradation avoids the prepn. of acid chlorides by using in their place carboxylic alkoxyformic anhydrides intermediates well-known in peptide chemistry. Among recent developments in this latter field are the use of mixed anhydrides prepared with diphenylketene an improved peptide synthesis via azides prepared with nitrosyl chloride or butyl nitrite instead of aq. sodium nitrite and a rapid synthesis directly from acid hydrazides with N-bromosuccinimide Oligopeptides and /5-lactams have been synthesized from simple starting materials and isonitriles,... 

It is assumed that NaAlCl4 is dissociated into sodium and tetrachloroaluminate ions. Torsi and Mamantov [35] have investigated a further dissociation of the tetrachloroaluminate ion in molten sodium chloroaluminates by potentiometric studies. For the 50 50 mol% composition of NaCl-AlCl3 the principal anion is A1C14. In acidic melts it was assumed that the reaction A1C13 + A1C14 <-> A12C17 is quantitative. More important is the con-... 

Molten sodium tetrachloroaluminate (a 1 1 mixture of NaCl and AICI3) is a good reaction medium for the Friedel-Crafts acylation reaction given in fig. 3.3 (Wade et al., 1979). Whereas the classical procedure for the synthesis of 1-indane from 3-phenylpropanoic acid consists of three reaction steps with a total reaction time of ca. six hours (Gattermann et al., 1982), the molten salt reaction is finished in five minutes and gives an even better yield (Wade et al., 1979). 

Other Substituted Diazonium Ions. A series of aminodiazonium ions have been prepared under superacidic conditions [Eq. (4.141)]. Schmidt495 described the preparation and IR spectra of protonated hydrazoic acid 212 and methylazide as their hexachloroantimonate salts. Olah and co-workers496 have carried out a comprehensive study on aminodiazonium ions (protonated azides) by H, 13C, and 15N NMR spectroscopy. Even the electrophilic aminating ability of aromatics of 212 has been explored.496 The tetrachloroaluminate salt of 212 has also been prepared496... 

The first reagent combination, carboxylic acid chloride/A1C13, reacts via the A1C13 complex A of the acid chloride or via the acylium tetrachloroaluminate B formed from it by /)-elimination. A carboxylic acid anhydride and A1C13 react via analogous electrophiles, namely via the A1C13 complex D of the anhydride or via the acylium salt E formed therefore by a /T elimination. The protonated anhydride F and the protonated carboxylic acid C are the reactive electrophiles of the Friedel-Crafts acylations catalyzed by Bronsted acids. 

Pentathiazyl tetrachloroaluminate(l —) and, to a lesser extent, penta-thiazyl tetrachloroferrate(l —) are moisture-sensitive both are soluble in thionyl chloride, anhydrous formic acid, and concentrated sulfuric and nitric acids. On dissolution in acid, hydrogen chloride is evolved because of decomposition of the anion. The solution in anhydrous formic acid can be used to prepare other salts by metathesis.7 The hexachloroantimonate(l —) undergoes almost no reaction when exposed to water or moist air for 24 hr. 

Homogeneous catalysts used for polyolefin degradation have mostly been classical Lewis acids such as AICI3, metal tetrachloroaluminates melts and more recently, new catalytic systems based on organic ionic liquids. 

One of the early examples of the use of sodium tetrachloroaluminate in intramolecular Friedel-Crafts acylation reactions involved the reaction shown in equation (49), in which P-(3-acenaphthoyl)propanoic acid was converted into perisuccinoylacenaphthene. The formation of the benzosuberanone ring system is particularly easy when electron-releasing substituents are present on the benzene ring. Under those cir-... 

An elegant entry into the phosphonic acid series is provided by the reaction of phosphorus trichloride with alkyl chlorides in the presence of anhydrous aluminum chloride, as discovered by American189 and British investigators.190> 191 The alkyl chloride is added in up to 25% excess, with exclusion of moisture and if necessary with cooling, to an equimolar mixture of phosphorus trichloride and aluminum chloride the alkyltrichlorophosphonium tetrachloroaluminate, generally in crystalline form, is obtained and is then dissolved in methylene dichloride and hydrolysed cautiously to the phosphonic dichloride ... 

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