Derivatives of organic compounds are often prepared in order to confirm structures proposed. In this experiment a ketone will be converted to its 2,4-dinitrophenylhydrazone derivative.
Suspend 0.25 g of 2,4-dinitrophenylhydrazine (toxic!) in 5 mL of methanol and add 0.5 mL of concentrated sulphuric acid cautiously. Filter the warm solution if necessary and add a solution of 0.2 g cyclohexanone in 1 mL of methanol. Filter the derivative formed and recrystallise from methanol or ethanol. Use a Hirsch funnel for filtering the recrystallised material. Describe the mechanism of the reaction above.
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