还原反应( Reduction) a The reduction products depends on the reaction conditions used Ei- Reduction of the nitro group actually proceeds in a series of tow-electron steps NO2 NO NHOH NH 2e+2H 2e+2H 2e+2H ①D H,O Nitrobenzene Nitrosobenzene Pheny hydroxylamine Aniline ⑨D
Organic Chemistry Organic Chemistry Xiamen Xiamen University University 还原反应(Reduction) The reduction products depends on the reaction conditions used. Reduction of the nitro group actually proceeds in a series of tow-electron steps. NO 2 NO NHO H NH 2 2 e + 2 H + H 2 O 2 e + 2 H + 2 e + 2 H + H 2 O Nitrobenze n e Nitrosobenze n e Phenylhydroxylam i n e An ilin e
单分子还原 Ch NO2 H2/Ni CH NH pressure,△ CH(CH3h287-90% CH(CH3h2 NO H,/Pt EtoH CCH32100% C(CH3)3
Organic Chemistry Organic Chemistry Xiamen Xiamen University University 单分子还原 CH 3 CH(CH3 ) 2 NO 2 H 2/ Ni p ressure, CH 3 CH(CH3 ) 2 NH2 87 ~ 90% NO 2 C(CH3 ) 3 NH 2 C(CH3 ) 3 H 2/ Pt EtOH 100%
9 Catalytic hydrogenation and chemical reducing agents in acidic media give the corresponding amines in high yield CH CH nO2 NHo Fe/HCl EtOH.△ NO 74% NH 2 NO NH3 NH2 ①D Snc Naoh conc. HC ⑨D CHO CHO CHO 常用:e/HC|,Zn/HC
Organic Chemistry Organic Chemistry Xiamen Xiamen University University Catalytic hydrogenation and chemical reducing agents in acidic media give the corresponding amines in high yield. CH 3 NO 2 NO 2 Fe / H C l EtOH, CH 3 NH 2 NH 2 74% NO 2 CHO NH 3 CHO NH 2 CHO SnC l 2 NaOH conc. H C l 常用 :Fe / HCl Zn / HCl
NayS, Nash, (NHah2sS, NHSH NO NH Nash EtOH.△ NO279~85% NO2 NH NH, nO2 NH HOS. NHAOH EtOH.△ NO2 52~58% NO2
Organic Chemistry Organic Chemistry Xiamen Xiamen University University Na 2S, NaSH, ( N H 4 ) 2S, NH 4SH NO 2 NO 2 NH 2 NO 2 NaS H EtOH, NH2 NO 2 NO 2 NH 2 NO 2 NH2 79 ~ 85% H 2S, N H 4OH EtOH, 52 ~ 58%
In acid the intermediate compounds cannot be isolated but are reduced rapidly in turn In neutral media, a higher reduction potential is required and reduction is readily stopped at the hydroxylamine stage NO NHOH Zn, aq. NH4CI 65
Organic Chemistry Organic Chemistry Xiamen Xiamen University University In acid the intermediate compounds cannot be isolated, but are reduced rapidly in turn In neutral media, a higher reduction potential is required and reduction is readily stopped at the hydroxylamine stage. NO 2 NHOH 65 Zn, aq. N H 4Cl