- Amyl alcohol
Amyl alcohol is an
organic compoundwith the formula C5H11OH. All eight isomers of amyl alcoholare known:
Three of these alcohols, active amyl alcohol, methyl (n) propyl carbinol, and methyl isopropyl carbinol, are optically active, as they contain an asymmetric carbon atom.
The most important is isobutyl carbinol, this being the chief constituent of fermentation amyl alcohol, and consequently a constituent of
fusel oil. It can be separated from fusel oil by shaking with strong brinesolution, separating the oily layer from the brine layer and distilling it, the portion boiling between 125 and 140 °C. being collected. For further purification it may be shaken with hot lime water, the oily layer separated, dried with calcium chlorideand fractionated, the fraction boiling between 128 and 132 °C only being collected. It may be synthesized from isobutanolby conversion into isovaleraldehyde, which is subsequently reduced to isobutyl carbinol by means of sodium amalgam.
It is a colourless liquid of density 0.8247 g/cm³ (0 °C), boiling at 131.6 °C, slightly soluble in water, easily soluble in organic solvents. It possesses a characteristic strong smell and a sharp burning taste. When pure, it is nontoxic, while the impure product is toxic. On passing its vapour through a red-hot tube, it decomposes with production of
acetylene, ethylene, propylene, and other compounds. It is oxidized by chromic acidto isovaleraldehyde, and it forms crystalline addition compounds with calcium chlorideand tin(IV) chloride.
The other amyl alcohols may be obtained synthetically. Of these, tertiary butyl carbinol has been the most difficult to obtain, its synthesis having first been reported in
1891, by L. Tissier ("Comptes Rendus", 1891, 112, p. 1065) by the reduction of a mixture of trimethyl acetic acid and trimethylacetyl chloride with sodium amalgam. It is a solid that melts at 48 to 50 °C and boils at 112.3 °C.
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