E2 Elimination (Dehydrohalogenation)

C₂H₅Br + KOH → C₂H₄ + KBr + H₂O

Visão geral

Strong base (KOH in ethanol) removes a beta-hydrogen and the halide leaves simultaneously in a concerted E2 elimination to form an alkene. The H and Br must be anti-periplanar (180 degrees) for the elimination to proceed. E2 competes with SN2, with bulky bases and secondary/tertiary substrates favoring elimination.

Participantes

Papel	Substância	Coeficiente	Estado
Reagente	Potassium Hydroxide KOH	1	(aq)
Produto	Ethylene C₂H₄	1	(g)
Produto	Water H₂O	1	(l)

Exemplo do cotidiano

E2 elimination is used to prepare alkenes from easily available alkyl halides and is key to understanding organic reaction selectivity.

Importância industrial

A eliminação E2 é utilizada na síntese industrial de alcenos, incluindo a desidrohalogenação de cloroparafinas para produzir alcenos lineares utilizados em detergentes.

Propriedades

Tipo: Organic
Reversível: Não
Energia: Exotérmico
ΔH: -50,0 kJ/mol

Reações relacionadas

Epoxidation of Alkenes (mCPBA) Swern Oxidation Oxidation of Secondary Alcohol to Ketone Claisen Condensation (Ethyl Acetate) Aldol Condensation of Acetaldehyde Kolbe Electrolysis Baeyer-Villiger Oxidation Beckmann Rearrangement (Cyclohexanone Oxime) Catalytic Hydrogenation of Ethylene Dehydration of Ethanol

Frequently Asked Questions

What is the equation for E2 Elimination (Dehydrohalogenation)?

The balanced equation is: C₂H₅Br + KOH → C₂H₄ + KBr + H₂O.

What type of reaction is E2 Elimination (Dehydrohalogenation)?

E2 Elimination (Dehydrohalogenation) is a organic reaction.

Is E2 Elimination (Dehydrohalogenation) exothermic or endothermic?

E2 Elimination (Dehydrohalogenation) is exothermic (releases energy). The enthalpy change (ΔH) is -50.0 kJ/mol.