arenes Flashcards
Implication of pi electron cloud destabilisation
- Resonance stabilisation
2. Extra stability
Mechanism that arenes undergo
Electrophilic substitution
Reagent and conditions for benzene to form nitrobenzene
Reagent and condition: Concentrated HNO3, concentrated H2SO4 as Bronsted Lowry acid catalyst, maintained at 55 °C
Observations: Pale yellow oily liquid formed
Reagent and conditions for benzene to form bromobenzene
Reagent and conditions: Br2(l), FeBr3 as Lewis acid catalyst, warm
Observations: Reddish-brown Br2(l) decolourises
Reagent and condition for benzene to form chlorobenzene
Reagent and conditions: Cl2(g), FeCl3 as Lewis acid catalyst, warm
Observations: Greenish-yellow Cl2(g) decolourises
Reagent and conditions in Friedel-Crafts alkylation to form methylbenzene from benzene
Reagent and conditions: Chloroalkane, AlCl3 as Lewis acid catalyst, warm
Observations: White fumes of HCl
Reagent and conditions to form 2/4 - bromomethylbenzene from methylbenzene
Reagent and conditions: Br2(l), FeBr3 as Lewis acid catalyst, room temperature and absence of UV
Observations: Reddish-brown Br2(l) decolourises.
Reagent and condition to form 2/4-chloromethylbenzene from methylbenzene
Reagent and conditions: Cl2(l), FeCl3 as Lewis acid catalyst, room temperature and absence of UV
Observations: Greenish-yellow Cl2(g) decolourises
Reagent and condition to form 2/4-nitromethylbenzene
Reagent and conditions: Concentrated HNO3, concentrated H2SO4 as Bronsted Lowry acid catalyst, maintained at 30 °C
Observations: Yellow oily liquid formed
Reagent and condition for Friedal-Crafts alkylation from methylbenzene
Reagent and conditions: Chloroalkane, AlCl3 as Lewis acid catalyst, room temperature
Observations: White fumes of HCl
Reagent and conditions for free radical substitution as a side chain reaction of methylbenzene
Reagent and conditions: Cl2(g), UV light or heat
Observations: Greenish-yellow Cl2 decolourises
Reagent and conditions for free radical substitution as a side chain reaction of methylbenzene
Reagent and conditions: Br2(g), UV light or heat
Observations: Reddish-brown Br2 decolourises
Reagent and conditions for side chain oxidation of methylbenzene to benzoic acid
Reagent and conditions: KMnO4(aq), dilute H2SO4, heat
Observations: Purple KMnO4 decolourises and white ppt of benzoic acid
Reagent and conditions for side-chain oxidation of methylbenzene to form sodium benzoate
Reagent and conditions: KMnO4 (aq), dilute NaOh, heat
Observations: Purple KMnO4 decolourises and brown precipitate of manganese dioxide is formed