Benzyl alcohol

Details:

Benzyl alcohol is an aromatic alcohol with the formula C6H5CH2OH. The benzyl group is often abbreviated "Bn" (not to be confused with "Bz" which is used for benzoyl), thus benzyl alcohol is denoted as BnOH. Benzyl alcohol is a colorless liquid with a mild pleasant aromatic odor. It is a useful solvent due to its polarity, low toxicity, and low vapor pressure. Benzyl alcohol is partially soluble in water (4 g/100 mL) and completely miscible in alcohols and diethyl ether.
Natural occurrences
Benzyl alcohol is produced naturally by many plants and is commonly found in fruits and teas. It is also found in a variety ofessential oils including jasmine, hyacinth, and ylang-ylang.
It is also one of the chemical compounds found in castoreum. This compound is gathered from the beaver plant food.
PreparationBenzyl alcohol is prepared by the hydrolysis of benzyl chloride using sodium hydroxide:
C6H5CH2Cl + NaOH → C6H5CH2OH + NaCl
It can also be prepared via a Grignard reaction by reacting phenylmagnesium bromide (C6H5MgBr) with formaldehyde, followed by acidification.
ReactionsLike most alcohols, it reacts with carboxylic acids to form esters. In organic synthesis, benzyl esters are popular protecting groups because they can be removed by mild hydrogenolysis.
Benzyl alcohol reacts with acrylonitrile to give N-benzylacrylamide. This is an example of a Ritter reaction:
C6H5CH2OH + NCCHCH2 → C6H5CH2N(H)C(O)CHCH2
Applications[edit]Benzyl alcohol is used as a general solvent for inks, paints, lacquers, and epoxy resin coatings. It is also a precursor to a variety of esters, used in the soap, perfume, and flavor industries. It is also used as a photographic developer.
Nanotechnological uses Benzyl alcohol has been used as a dielectric solvent for the dielectrophoretic reconfiguration of nanowires.
Use in health care Benzyl alcohol is used as a bacteriostatic preservative at low concentration in intravenous medications, cosmetics and topical drugs.
The use of benzyl alcohol as a 5% solution has been approved by the U.S. FDA in the treatment of head lice in children older than 6 months and in adults.
Other uses Benzyl alcohol has nearly the same refraction index of quartz and wool fibre. If a clear quartz object is immersed in benzyl alcohol, it becomes almost invisible. This has been used as a method to non-destructively recognize if an object is made of true quartz or not (see crystal skull). Similarly, white wool immersed in benzyl alcohol also becomes almost invisible clearly revealing contaminants such as dark and medullated fibres and vegetable matter.