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, with thiosulfate being formed as a by-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] for example in the synthesis of 3-nitroaniline from 1,3-dinitrobenzene
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).
^Sebla Dincer (2002). "The preferential reduction of 4,6 (5,7)-dinitro and 5,6-dinitrobenzimidazoles". Dyes and Pigments. 53 (3): 263–266. doi:10.1016/S0143-7208(02)00018-9.