When

(semicarbazide) reacts with a ketone (or an aldehyde) to form a derivative known as a semicarbazone, only one nitrogen atom of semicarbazide acts as a nucleophile and attacks the carbonyl carbon atom of the ketone. The product of the reaction, consequently, is

What factor accounts for the fact that two nitrogen atoms of semicarbazide are relatively non-nucleophilic?

Transcribed Image Text:

R(H) O NH2 rather than N NHNH2 R(H) H