Selective mono-methylation of phenylacetonitrile to 2-phenylpropionitrile by dimethyl carbonate as an alkylating agent was studied for the first time using alkali-ion-exchanged and organic base functionalized MCM-41 as catalyst. 3-Aminopropylsilyl functionalized NH2-Na-Al-MCM-41 is found to be the superior catalyst among a series of alkali-ion-exchanged MCM-41 and microporous basic zeolite catalysts giving 98.4 wt% conversion of phenylacetonitrile and >92 wt% selectivity to 2-phenylpropionitrile.