Description
Propargyl bromide is a Shock sensitive liquid, lachrymator. Supplied
as an 80% solution in toluene stabilized with magnesium
oxide. Alternative formulations are currently under
development.
Chemical Properties
yellow solution
Uses
Propargyl bromide, 80% in toluene is used to prepare betulonic acid-peptide conjugates with anti-inflammatory activity and propargylic amines employed in enyne metathesis. It finds application in the propargylation of spiro ketones, allylic alcohols and enone complexes. In Barbier-type reaction, it reacts with aldehydes to give alkyne alcohols. It is actively involved in the synthesis of polyethylene glycol (PEG) and peptide-grafted polyesters.
Uses
Propargyl Bromide is used in the synthesis of betulonic acid-peptide conjugates with anti-inflammatory activity. It is also used in the synthesis of PEG and peptide-grafted polyesters and make propargylic amines employed in enyne metathesis. Additionally, It is Employed in the propargylation of spiro ketones, allylic alcohols, and enone complexes.
Preparation
Add hydrogen bromide and solvent into the reaction flask, in the presence of CuBr and Cu catalyst, add propargyl alcohol dropwise with stirring, after the drop is completed, the temperature is slightly raised to react, and then post-processing, rectification to obtain bromopropane. alkyne. Reaction equation: CH≡C-CH2OH+HBr→CH≡C-CH2Br+H2O or the product can also be obtained by reacting propargyl alcohol with (PhO)3PBr2 in the presence of pyridine.
It is derived from the reaction of propargyl alcohol with phosphorus bromide. The propargyl alcohol was added to pyridine under cooling, and phosphorus tribromide was slowly added dropwise with stirring at -5°C, and the reaction temperature was maintained below 0°C. After the addition was completed, stirring was continued for 15 min. Then, vacuum distillation is performed to collect all the distillate, and fractional distillation is carried out again under normal pressure to obtain the finished product. Or add a small amount of pyridine to dry propargyl alcohol, add phosphorus tribromide and a small amount of pyridine solution dropwise at 0 °C under stirring, stir for 20 min after dropping, and distill under reduced pressure to obtain the product. Reaction equation: CH≡C-CH2OH+PBr3→CH≡C-CH2Br
General Description
A colorless to light yellow liquid substance with a sharp odor. Flash point 65°F. Denser than water and insoluble in water. Vapors are heavier than air. May be irritating to skin and eyes. Used to make other chemicals. 3-Bromopropyne may decompose explosively with mild shock.
Air & Water Reactions
Highly flammable. Insoluble in water.
Reactivity Profile
3-Bromopropyne is soluble in alcohol, ether, chloroform, carbon tetrachloride and carbon disulfide. 3-Bromopropyne is highly flammable and a dangerous fire risk, sensitive to shock. 3-Bromopropyne is used in organic syntheses, preparation of resins and perfume intermediates [Hawley]. There is a high danger of formation of explosive metal acetylides, when 3-Bromopropyne comes in contact with copper, high-copper alloys, mercury, or silver.
Hazard
Flammable, dangerous fire and explosion
risk. Irritant.
Health Hazard
3-Bromopropyne is very toxic via the oral route. If inhaled, may be harmful; contact may cause burns to skin and eyes.
Fire Hazard
3-Bromopropyne detonates at 428F or more; ignites by impact. Emits highly toxic fumes of bromides when heated to decomposition. Reacts vigorously with oxidizing materials. Becomes shock-sensitive when mixed with chloropicrin. Unstable, avoid heat, flame, shock, and other chemicals
Pharmacology
Mode of action is considered
to be reaction with nucleophiles in living organisms.
Safety Profile
A poison by ingestion.
A dangerous fire hazard when exposed to
heat or flame. The aerated liquid may be
ignited by pressure. A dangerous, extremely
shock-sensitive explosive. It can detonate
when heated to 22O°C, by impact (especially
when mixed with chloropicrin), or when
heated whde confined. May explode on
contact with copper, high copper alloys,
mercury, or silver. Mixtures with
trichloronitromethane are shockand heat-
sensitive explosives. Can react vigorously
with oxidizing materials. To fight fire, use
water, foam, CO2, dry chemical. When
heated to decomposition it emits highly
toxic fumes of Br-. See also ACETYLENE
COMPOUNDS and BROMIDES.
Metabolism
Reacts slowly with water
to yield propargyl alcohol and bromide ion. It is expected
to move as a typical fumigant through the soil. Probably
not an ozone-depleting substance due to decomposition on
absorption of ultraviolet light.
