Chemical Properties
off-white powder or White or colorless crystals. M.P. 69℃. B.p. 281℃. Practically insoluble in water, soluble in alcohol, miscible with oils. The crystals have a very faint musty-rosy
odor, somewhat similar to that of Benzophenonc and Trichloromethyl phenyl carbinyl
acetate.
Uses
- Benzhydrols are industrially important compounds. On oxidation Benzhydrols yields Benzophenone, which are useful synthones for fullerenes, bioactive oxygen heterocycles, dyes and medicines. Various Cr (VI) and other oxidizing agents are used for oxidizing benzhydrol.
- Benzhydrol is widely used as intermediates in pharmaceuticals (including antihistamines), agrochemicals, perfumes and other organic compounds. It is used as a fixative in the perfume industry. It is involved in polymerization reaction as a terminating group. It is used as precursor to prepare modafinil, benztropine and diphehydramine.
- Intermediate in the preparation of Modafinil (M482500).
Uses
Anchoring of carboxylic acids and alcohols
Definition
ChEBI: Diphenylmethanol is a secondary alcohol that is diphenylmethane which carries a hydroxy group at position 1. It has a role as a rat metabolite, a bacterial xenobiotic metabolite, a human xenobiotic metabolite and a human urinary metabolite. It is a secondary alcohol and a member of benzyl alcohols. It derives from a hydride of a diphenylmethane.
Preparation
By reduction of Benzophenone, e.g. with zinc in aqueous alkali.
Reactions
Benzhydrol is oxidized to benzophenone, by sodium hypochlorite (commonly known as bleach) in the presence of a phase-transfer catalyst.
Synthesis: In a 20-mL green capped vial, place 1.5 mL of ethyl acetate, 100 mg (0.54 mmol) of benzhydrol and a few drops of methyltricaprylammonium chloride solution (Stark's catalyst or tricaprylmethylammonium chloride). Add a half-inch magnetic stirring bar, and stir until all reagents are dissolved. Cool the solution in an ice bath and add 2 mL of 5% NaOCl (aq) (bleach) dropwise using a 2.5- mL syringe. After the addition of the hypochlorite is complete, allow the reaction to stir for five minutes in the ice-water bath and then stir for a period of one hour at room temperature.
Reduction of benzophenone to benzhydrol.
4MPDC (4-Methyl pyridinium di chromate) is used as oxidizing agent to oxidize benzhydrol. PDC is a mild and selective oxidizing agent and is soluble in water and many organic solvents. Therefore, advantage over inorganic dichromate.
General Description
Pharmaceutical secondary standards for application in quality control provide pharma laboratories and manufacturers with a convenient and cost-effective alternative to the preparation of in-house working standards
Purification Methods
Crystallise benzhydrol from hot H2O or pet ether (b 60-70o), pet ether containing a little *benzene, from CCl4, or EtOH (1mL/g). An additional purification step includes passage of a *benzene solution through an activated alumina column. It sublimes in a vacuum. Also recrystallise it three times from MeOH/H2O [Naguib J Am Chem Soc 108 128 1986]. [Beilstein 6 IV 4648.]
Toxics Screening Level
The ITSL for Benzhydrol has been set at 16 μg/m3 based on annual average
time.
