Description
2-Bromopropane, also known as isopropyl bromide and 2-propyl bromide, is the halogenated hydrocarbon with the formula CH3CHBrCH3. It is a colorless liquid. It is used for introducing the isopropyl functional group in organic synthesis. 2-Bromopropane is prepared by heating isopropanol with hydrobromic acid.
Chemical Properties
colourless liquid
Uses
2-Bromopropane serves as an alkylating agent in organic synthesis. It is also used as an intermediate to form alkylated amines and alkylated metallic compounds. Further, it acts as a solvent for industrial cleaning, degreasing, metal processing and finishing, electronics, aerospace and aviation, aerosols, textiles, adhesives and inks. In addition, it is used for introducing the isopropyl functional group in organic synthesis.
Uses
2-Bromopropane is a general reagent used to introduce isopropyl group as in the case of the synthesis of various Buchwald ligands. It can also be used as a starting material in the total synthesis of lamellarin D, lamellarin H, ningalin B and (±)-dichroanal. It is sometimes used as an alternative to ozone-depleting cleaning solvents such as chlorofluorocarbons.
Preparation
2-Bromopropane is commercially available. It may be prepared in the ordinary manner of alkyl bromides, by reacting isopropanol with phosphorus and bromine, or with phosphorus tribromide.
Health Hazard
2-bromopropane, apparently caused ovarian failure, azoospermia, oligospermia, and anemia in a group of Korean workers. Experimental studies confirm specific reproductive effects in females and males. Hematopoietic effects and peripheral neuropathy also have been reported in animal studies. There is limited evidence of adverse effects in exposed workers similar to those seen in animals.
Safety Profile
Moderately toxic by
intraperitoneal route. A very flammable
liquid and dangerous fire hazard. When
heated to decomposition it emits toxic
fumes of Br-. See also BROMIDES.
Purification Methods
Wash the bromide with 95% H2SO4 (concentrated acid partially oxidised it) until a fresh portion of acid did not become coloured after several hours, then with water, aqueous NaHSO3, aqueous 10% Na2CO3 and again with water. (The H2SO4 can be replaced by conc HCl.) Prior to this treatment, isopropyl bromide has been purified by bubbling a stream of oxygen containing 5% ozone through it for 1hour, followed by shaking with 3% hydrogen peroxide solution, neutralising with aqueous Na2CO3, washing with distilled water and drying. Alternatively, it has been treated with elemental bromine and stored for 4 weeks, then extracted with aqueous NaHSO3 and dried with MgSO4. After the acid treatment, isopropyl bromide can be dried with Na2SO4, MgSO4 or CaH2, and fractionally distilled. [Beilstein 1 IV 208.]
