2-Bromopropane
[CAS# 75-26-3]

Identification

• Classification: Chemical pesticide >> Herbicide >> Amide herbicide
• Name: 2-Bromopropane
• Synonyms: Isopropyl bromide
• Molecular Formula: C₃H₇Br
• Molecular Weight: 122.99
• CAS Registry Number: 75-26-3
• EC Number: 200-855-1
• SMILES: CC(C)Br

Properties

• Density: 1.3±0.1 g/cm³ Calc.^*, 1.31 g/mL (Expl.)
• Melting point: -89 °C (Expl.)
• Boiling point: 60.6±8.0 °C 760 mmHg (Calc.)^*, 59 °C (Expl.)
• Flash point: 19.4 °C (Calc.)^*, 19 °C (Expl.)
• Solubility: water 0.3 g/100 mL (Expl.)
• Index of refraction: 1.429 (Calc.)^*, 1.425 (Expl.)

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS02;GHS08 Danger
• Risk Statements: H225-H360F-H373
• Safety Statements: P203-P210-P233-P240-P241-P242-P243-P260-P280-P303+P361+P353-P318-P319-P370+P378-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	2	H225
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Reproductive toxicity	Repr.	1A	H360
Reproductive toxicity	Repr.	1A	H360F
Reproductive toxicity	Repr.	1A	H360F

• Transport Information: UN 2344

Discovery and Applications

2-Bromopropane, also known as isopropyl bromide, is a simple secondary alkyl halide with the molecular formula C₃H₇Br. It is a colorless liquid with a mild ether-like odor and belongs to the class of haloalkanes, in which a bromine atom is covalently attached to the secondary carbon of a propyl group. Its secondary carbon-bromine bond makes it more reactive in nucleophilic substitution reactions than primary bromides in some contexts, while also being prone to elimination reactions under basic conditions.

The discovery of 2-bromopropane stems from the development of bromination methods for alcohols in the 19th century. It was initially synthesized through the reaction of isopropanol with hydrobromic acid under acidic conditions, where the hydroxyl group of isopropanol is substituted with a bromine atom. Subsequent improvements included the use of phosphorus tribromide or other brominating agents to increase reaction efficiency and reduce byproducts. These methods established reliable routes for producing 2-bromopropane on both laboratory and industrial scales.

2-Bromopropane is widely used as an intermediate in organic synthesis. Its secondary bromide functionality allows it to act as an alkylating agent for a variety of nucleophiles. In pharmaceutical chemistry, it is employed to synthesize isopropylated derivatives of amines, alcohols, and heterocycles, which can influence biological activity, solubility, and metabolic stability. Its use in agrochemical production enables the construction of isopropyl-substituted intermediates for herbicides, insecticides, and fungicides.

In polymer chemistry, 2-bromopropane can introduce isopropyl groups into monomers or polymer chains through nucleophilic substitution, creating branched or functionalized polymers. These modifications can enhance polymer flexibility, solubility, or reactivity for further chemical transformations. Its versatility also makes it useful in laboratory research as a reagent for mechanistic studies of nucleophilic substitution and elimination reactions, providing insights into reaction kinetics and stereochemical outcomes.

Mechanistically, 2-bromopropane participates in both S_N2 and S_N1 reactions. The secondary carbon-bromine bond is more hindered than in primary bromides, which affects the reaction pathway depending on the nucleophile, solvent, and temperature. Strong nucleophiles in polar aprotic solvents typically favor S_N2 substitution, while polar protic solvents and weak nucleophiles can lead to S_N1 reactions with carbocation intermediates. Under strongly basic conditions, elimination reactions can produce propene. This dual reactivity makes 2-bromopropane a useful compound for studying organic reaction mechanisms.

Physically, 2-bromopropane is slightly soluble in water but miscible with most organic solvents including ethers, alcohols, and hydrocarbons. It is highly flammable, volatile, and requires careful storage and handling in well-ventilated areas away from heat and ignition sources. Safety considerations are important, as 2-bromopropane can be toxic if inhaled or absorbed through the skin, and environmental exposure should be minimized. Proper protective equipment and disposal protocols are essential when working with this chemical.

Overall, 2-bromopropane is an important secondary alkyl halide with diverse applications in organic synthesis, pharmaceuticals, agrochemicals, and polymer chemistry. Its reactivity as a bromide, versatility in substitution and elimination reactions, and utility in introducing isopropyl groups make it a valuable reagent for chemical research and industrial applications.

References

2025. Novel 1,3,4-oxadiazole-nicotinamide hybrids as non-classical AHL mimics quorum sensing inhibitors of Pseudomonas aeruginosa: design, synthesis and biological evaluation. BMC Chemistry, 19.
DOI: 10.1186/s13065-025-01560-9

2024. Ni-catalysed remote C(sp3)–H functionalization using chain-walking strategies. Nature Reviews Chemistry, 8(10).
DOI: 10.1038/s41570-024-00649-4

2024. Repurposing of halogenated organic pollutants via alkyl bromide-catalysed transfer chlorination. Nature Chemistry, 16(6).
DOI: 10.1038/s41557-024-01551-8