ChEBI: A tetrabutylammonium salt with bromide as the anionic counterpart.
Crystallise the salt from *benzene (5mL/g) at 80o by adding hot n-hexane (three volumes) and allowing to cool. Dry it over P2O5 or Mg(ClO4)2, under vacuum. The salt is very hygroscopic. It can also be crystallised from ethyl acetate or dry acetone by adding diethyl ether and dried in vacuo at 60o for 2 days. It has been crystallised from acetone by addition of diethyl ether. It is so hygroscopic that all manipulations should be carried out in a dry-box. It has been purified by precipitation from a saturated solution in dry CCl4 on addition of cyclohexane or by recrystallisation from ethyl acetate, then heating in vacuum to 75o in the presence of P2O5. [Symons et al. J Chem Soc, Faraday Trans 1 76 2251 1908.] It also recrystallises from CH2Cl2/diethyl ether and is dried in a vacuum desiccator over P2O5. [Blau & Espenson J Am Chem Soc 108 1962 1986, Beilstein 4 IV 657.]
(1) Used as a reagent for the analysis of organic synthesis.
(2) Tetrabutylammonium bromide is also an effective phase transfer catalyst.
Phase transfer catalyst, referred to as PTC, is able to transfer the aqueous phase (or organic phase) to the organic phase (or aqueous phase) catalyst, which can make the reaction between the aqueous phase and the organic phase of the catalyst. PTC has the function of changing the degree of ion solvation, increasing the activity of ion reaction, speeding up the reaction rate and so on. Solve the problem of the past in the two phases of the reaction is difficult to react.
Common quaternary ammonium salt phase transfer catalysts are: benzyl triethyl ammonium chloride, trioctyl methyl ammonium chloride, tetramethyl ammonium bromide, tetrapropylammonium chloride, tetrabutylammonium bromide , tetrabutyl ammonium iodide, benzyl triethyl ammonium bromide, triethyl hexyl bromide, octyl triethylammonium bromide.
Phase transfer catalyst is widely applied in organic synthesis: R2C for preparing compounds (carbene type compound), further preparation of the corresponding nitrile, isonitrile, Halon, dichloromethane cyclopropane derivatives, hydroxy acids and diazomethane. For the alkylation reaction, compared with traditional methods, to avoid the harsh conditions of dry operation, and high yield, it can also be used in the redox reaction, ester hydrolysis, substitution reaction, condensation reaction, addition reaction, polymerization reaction, addition reaction of carbon and the elimination of reaction and so on.
(3) For organic synthesis intermediates, phase transfer catalyst
(4) Ion-pairing reagents for the synthesis of bacampicillin, sultamicillin like.
(5) Ion pair chromatography reagents, phase transfer catalyst. Bacampicillin, sultamicillin like synthesis.
Physical and Chemical Properties
Tetrabutylammonium bromide, also known as tetrabutylammonium bromide. White crystal, deliquescence. 118 ℃ melting point. Soluble in water, alcohol, ether and acetone, slightly soluble in benzene.
Figure 1: a structural formula of tetrabutylammonium bromide
The acute oral LD50 (mouse): 590mg/kg. Inhalation, ingestion and skin contact toxic to the skin, eyes and respiratory system irritation.
More information from the ChemicalBook Xiaonan editor (2015-09-16).
white crystals or powder