Nicotine can be made when the following ammonium salt is treated with Na2CO3. Draw a stepwise mechanism for this reaction. N N N nicotine CH3 NH2CH3 Na2CO3 NaHCO3 NaBr

Explanation:

The mechanism showing the process of the reaction is as follows:

From the given information, the starting compound includes a bromine atom & a  protonated primary amine group. At the initial stage, dissociation of sodium carbonate occurs to form carbonate ions. This is followed by the attraction of a proton by the carbonate ion from the protonated amine group.

After that, there is a nucleophilic attack on the carbon atom at the nitrogen site by a bromine atom which results in the formation of a cyclic product. Finally, deprotonation of the nitrogen atom occurs to form Nicotine.

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be