5-Bromo-1-pentene 1119-51-3 organic building block for selective synthetic transformation

5-Bromo-1-pentene, also known as 4-Pentenyl bromide or 5-Bromopent-1-ene, belongs to aliphatic unsaturated brominated hydrocarbons. Its molecular structure carries two independent reactive functional groups: terminal carbon-carbon double bond and primary bromo substituent. This dual reactivity enables two separate reaction pathways without mutual interference under controlled reaction conditions. The substance appears as colorless to pale yellow clear liquid, immiscible in water and freely soluble in dichloromethane, chloroform and ethyl acetate. It remains stable under sealed cool conditions yet sensitive to strong oxidants, strong bases, prolonged heat and direct light. Uncontrolled exposure may trigger elimination or polymerization side reactions. It is widely adopted by synthetic chemists for carbon chain extension, heterocyclic skeleton construction and derivatization of bioactive analogues.

The bromo site undergoes classic SN2 nucleophilic substitution, convenient for introducing amine, cyano and thio groups. The terminal alkene can participate in epoxidation, hydroboration, metathesis and cycloaddition reactions. Researchers can selectively activate one functional group by adjusting solvent, temperature and catalyst system. This tunable reactivity makes it preferred for multi-step convergent synthesis routes.

It acts as a core starting material for bioactive molecule modification. It supports the preparation of nitrogen-containing heterocyclic compounds and functionalized fatty acid derivatives. It also serves as a precursor for agrochemical intermediates, functional polymer monomers and probe molecules for chemical biology studies. Custom carbon-chain lengthening projects frequently select this reagent to introduce terminal alkene tags.

Keep container fully sealed and protected with inert gas blanket for long-term stock. Store at 2–8 °C, away from heat sources, sparks, flame and incompatible oxidizing or alkaline materials. The working area requires sufficient ventilation. Wear splash goggles, nitrile gloves and protective lab coat during transfer and weighing. Avoid vapor inhalation, skin contact and eye exposure. Spillages need inert absorbent material and proper hazardous waste disposal.

Classified as flammable liquid with irritant properties. Vapor may form explosive mixtures with air. Direct contact causes eye and skin irritation. Inhalation of concentrated vapors irritates respiratory tract. All operations follow standard laboratory hazard control protocols.