Nikolai Aleksandrovich Menshutkin (Russian: ??????? ????????????? ?????????; 24 October [O.S.
12 October] 1842 – 5 February [O.S.
22 January] 1907) was a Russian chemist who discovered the process of converting a tertiary amine to a quaternary ammonium salt via the reaction with an alkyl halide, now known as the Menshutkin reaction.