SolutionsNitroderivatives
1. Silver nitrite
1-Iodooctane with AgNO2 gives mainly 1-nitrooctane, but also some octyl nitrite. Why are both products formed?
The nitrite anion is an ambident nucleophile: it can attack through the nitrogen (giving the nitro compound, R–NO2) or through one of the oxygens (giving the nitrite ester, R–O–N=O).
2. The acidity of nitromethane
Nitromethane has pKa = 10. Why is it so acidic for a compound with C–H bonds? Does it dissolve in aqueous NaOH?
Its conjugate base is resonance-stabilized: the negative charge is delocalized from the carbon onto the two oxygens of the nitro group. Yes: with NaOH (water has pKa 15.7) the soluble sodium salt is formed.
3. Synthesis with the anion
Propose a synthesis of 1-(aminomethyl)cyclohexanol from cyclohexanone and nitromethane.
The nitromethane anion (formed with a base) adds to the carbonyl of cyclohexanone to give 1-(nitromethyl)cyclohexanol (Henry reaction). Reduction of the nitro group (H2/Ni or LiAlH4) gives 1-(aminomethyl)cyclohexanol.