Nicotine consists of an N-methylpyrrolidine ring attached through its C-2 to C-3 of a pyridine ring. With one equivalent of acid, the proton goes mainly to

Athe pyridine nitrogen, because it is aromatic
Bthe N-methylpyrrolidine nitrogen, an sp $^{3}$ amine nitrogen (pKaH about 8), rather than the pyridine nitrogen (pKaH about 3)
Ca ring carbon of pyridine
Dboth nitrogens equally

Answer: B

Nicotine has two basic nitrogens: a tertiary aliphatic amine with a localised sp

^{3}

lone pair and a pyridine nitrogen with an sp

^{2}

lone pair, also made less basic by the electron-withdrawing ring. The aliphatic N is much more basic (pKaH about 8 versus about 3) and is protonated first.

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Nicotine consists of an N-methylpyrrolidine ring attached through its C-2 to C-3 of a pyridine ring. With one equivalent of acid, the proton goes mainly to

Answer: B

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