[anilin]

I need to know the two side products of the attached reaction. Which one of the 3 molecules will be the possible side products?
Thanks

[StarvinMarvin]

Structure 2 seems completely unreasonable due to the steric strains of three-member ring. Therefore the two remaining structures are the probable side products.

But there's more:

the dimer can also undergo the same reaction and the whole business might simply polymerize. It depends on conditions and stoichiometry you provide.

Apart from the possibility of polymerization, I think that stoichiometry of the reaction would also impact the likelihood of formation of structures 1 and 3.