Zinin reaction or Zinin reduction involves reduction of
nitro aromatic compounds to the
amines using sodium
sulfide.[1] It is used to convert
nitrobenzenes to
anilines.[2][3] The reaction selectively reduces nitro groups in the presence of other easily reduced functional groups (e.g., aryl halides and C=C bonds) are present in the molecule.
Reaction mechanism and example
The reaction requires water. Thiosulfate is one product. A possible
stoichiometry for the reaction is:
Mechanistic studies have implicated a role for disulfide that is generated in situ.
Nitrosobenzenes (ArNO) and
phenylhydroxylamine (ArNHOH) are probable intermediates.[4]
Dinitrobenzenes can often be reduced selectively to the nitroaniline. [5]
History
The reaction was discovered by a Russian organic chemist
Nikolay Zinin (Russian: Николай Николаевич Зинин) (25 August 1812, Shusha – 18 February 1880, Saint Petersburg).