Resorcinol for synthesis. CAS 108-46-3, EC Number 203-585-2,
chemical formula C₆H₄(OH)₂., for synthesis
Synonym: 1,3-Dihydroxybenzene
·
CAS Number 108-46-3
·
Linear Formula C₆H₆O₂
·
Molecular Weight 110.11 g/mol
·
EC Number 203-585-
Properties
|
Related Categories
|
Biochemicals
and Reagents More...
|
|
bp
|
281 °C (1013 hPa)
|
|
expl. lim.
|
1.4 %(V)
|
|
vapor pressure
|
0.1 hPa (20 °C)
|
|
solubility
|
1000 g/l
|
|
density
|
1.28 g/cm3 (20 °C)
|
|
flash point
|
127 °C
|
Resorcinol (or resorcin) is a benzenediol (m-dihydroxybenzene).
Detailed description
Production
It is produced when any of a large number of resins (e.g., galbanum, asafoetida, etc.) are melted with potassium hydroxide, or by the distillation of Brazilwood extract.
It may be prepared synthetically by melting 3-iodophenol, phenol-3-sulfonic
acid, or benzene-1,3-disulfonic acid with potassium carbonate; by the action of nitrous acid on 3-aminophenol or on 1,3-diaminobenzene.[9] Many ortho-
and para-compounds of the aromatic series (for example,
the bromophenols, benzene-para-disulfonic acid) also yield resorcinol on
fusion with potassium hydroxide.
Properties
Resorcinol crystallizes from benzene as colorless needles
that are readily soluble in water, alcohol, and ether, but insoluble in chloroform and carbon disulfide. It reduces Fehling's solution and ammoniacal silver solutions. It does not form
a precipitate with lead acetate solution, as does
the isomeric pyrocatechol. Iron(III) chloride colors its aqueous
solution a dark-violet, and bromine water precipitates
tribromoresorcin. These properties are what give it its use as a colouring
agent for certain chromatography experiments. Sodium amalgam reduces it to
dihydroresorcin, which when heated to 150 to 160 °C with concentrated barium hydroxide solution gives
γ-acetylbutyric acid (D. Vorlgnder); when fused with potassium hydroxide,
resorcinol yields phloroglucin, pyrocatechol, and diresorcin.
It condenses with acids or acid chlorides, in the presence of
dehydrating agents, to oxyketones, e.g., with zinc chloride and glacial acetic acid at 145 °C it
yields resacetophenone (HO)2C6H3~CO.CH3.[10] With the anhydrides of dibasic acids, it
yields fluoresceins. When heated with calcium chloride—ammonia to 200 °C it
yields meta-dioxydiphenylamine.[11] With sodium nitrite it forms a
water-soluble blue dye, which is turned red by acids, and is used as an indicator, under the name of
lacmoid.[12] It condenses readily
with aldehydes, yielding with formaldehyde, on the addition of
catalytic hydrochloric acid, methylene diresorcin
[(HO)C6H3(O)]2•CH2. Reaction with chloral hydrate in the presence of potassium bisulfate yields the lactone of
tetra-oxydiphenyl methane carboxylic acid.[13] In alcoholic
solution it condenses with sodium acetoacetate to form 4-methylumbelliferone.[14]
In addition to electrophilic aromatic addition,
resorcinol (and other poly-ols) undergo nucleophilic substitution via the enone
form. With concentrated nitric acid, in the presence of
cold concentrated sulfuric acid, it yields
trinitro-resorcin (styphnic acid),
which forms yellow crystals, exploding violently on rapid heating.
Occurrences
Presence of the resorcinol moiety
Parts of a molecule of catechin, another natural compound that is
present in tea, has the resorcinol skeleton structure in it.
Alkylresorcinols are a marker of
whole grain diet. 4-Hexylresorcinol is an anesthetic found in throat
losenges.
Applications
Medical
Used externally, it is an antiseptic and disinfectant, and is used 5 to
10% in ointments in the treatment of chronic skin diseases such as psoriasis, hidradenitis
suppurativa, and eczema of a sub-acute
character. It is present in over-the-counter topical acne treatments at 2% or
less concentration, and in prescription treatments at higher concentrations.[16] Weak, watery
solutions of resorcinol (25 to 35 g/kg) are useful in allaying the itching in erythematous
eczema. A 2% solution used as a spray has been used with marked
effect in hay fever and in whooping cough. In the latter
disease 0.6 mL of the 2% solution has been given internally. It can be included
as an anti-dandruff agent in shampoo or in sunscreen cosmetics. It has
also been employed in the treatment of gastric ulcers in doses of 125 to
250 mg in pills, and is said to be analgesic and haemostatic in its action. In
large doses, it is a poison, causing giddiness, deafness, salivation, sweating, and convulsions. It is also worked
up in certain medicated soaps. Monoacetylresorcinol, C6H4(OH)(O-COCH3),
is used under the name of euresol.[17] Resorcinol is one of
the active ingredients in products such as Resinol, Vagisil, and Clearasil.
Chemical
Resorcinol is also used as a chemical intermediate
for the synthesis of pharmaceuticals and other organic compounds. It is used in
the production of diazo dyes and plasticizers and as a UV absorber in resins.
An emerging use of resorcinol is as a template
molecule in supramolecular
chemistry. The -OH groups on resorcinol form hydrogen bonds to target molecules,
holding them in the proper orientation for a reaction. Many such reactions are
able to be carried out in the solid state, thereby reducing
or eliminating the use of solvents that may be harmful to the environment. (see Green chemistry)
Resorcinol is an analytical reagent for the
qualitative determination of ketoses (Seliwanoff's test).
Resorcinol is the starting material for resorcinarene molecules and the initiating explosive lead styphnate.[18]
Resorcinol reacts with formaldehyde to form a
thermoset resin which can form the basis of an aerogel.
250 g in Plastic bottle (8223030250)
$298.39/KG OR $135.63/IB
For more information:
mobile: +2348039721941
contact person: emeaba uche
e-mail: emeabau@yahoo.com
website: www.franchiseminerals.com
No comments:
Post a Comment