  Despite the fact that the majority of current models assume that interstellar
complex organic molecules (iCOMs) are formed on dust-grain surfaces, there is
some evidence that neutral gas-phase reactions play an important role. In this
paper, we investigate the reaction occurring in the gas phase between
methylamine (CH$_3$NH$_2$) and the cyano (CN) radical, for which only
fragmentary and/or inaccurate results have been reported to date. This case
study allows us to point out the pivotal importance of employing
quantum-chemical calculations at the state of the art. Since the two major
products of the CH$_3$NH$_2$ + CN reaction, namely the CH$_3$NH and
CH$_2$NH$_2$ radicals, have not been spectroscopically characterized yet, some
effort has been made for filling this gap.
