When semicarbazide reacts with a ketone (or aldehyde) to form semicarbazone. Only one nitrogen atom of semicarbazide acts as a nucleophile and attack the carbonyl carbon of the ketone. The product fo the reaction consequently is R_(2)C=N- NH-CONH_(2) rather than R_(2)C=NCONH-NH_2. what factor account for the fact that two nitrogen atoms of semicarbazide are relatively non nucleophilic ?

When semicarbazide reacts with a ketone (or aldehyde) to form semicarb

1.	When semicarbazide reacts with a ketone (or aldehyde) to form semicarbazone. Only one nitrogen atom of semicarbazide acts as a nucleophile and attack the carbonyl carbon of the ketone. The product fo the reaction consequently is R_(2)C=N- NH-CONH_(2) rather than R_(2)C=NCONH-NH_2. what factor account for the fact that two nitrogen atoms of semicarbazide are relatively non nucleophilic ?
Answer» ANSWER :Two nitrogen ATOMS of semicarbazide that are adjacent to the (C=O) group have their lone PAIR present in conjuction so NUCLEOPHILICITY decreases.