Nitric Acid → 3,3'-Diaminobenzidine

HRID 1819972Notes

Reaction equation

HRID 1819972 reaction equation
[N+:1]([C:4]1[CH:5]=[C:6]([C:14]2[CH:23]=[CH:22][C:17]([NH:18]C(=O)C)=[C:16]([N+:24]([O-])=O)[CH:15]=2)[CH:7]=[CH:8][C:9]=1[NH:10]C(=O)C)([O-])=O.[N+]([O-])(O)=O>C1(C2C=CC(N)=CC=2)C=CC(N)=CC=1.C(OC(=O)C)(=O)C.C(O)(=O)C>[NH2:1][C:4]1[CH:5]=[C:6]([C:14]2[CH:23]=[CH:22][C:17]([NH2:18])=[C:16]([NH2:24])[CH:15]=2)[CH:7]=[CH:8][C:9]=1[NH2:10]

Participants

6

Reactant 2

HCID 944Nitric AcidHCID 44632453,3'-dinitro-N,N'-diacetylbenzidine2×

Product 1

HCID 70713,3'-Diaminobenzidine

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 7111BenzidineSolventHCID 7918Acetic AnhydrideSolvent2×

Procedure

That is, amino groups in benzidine are first protected by N-acetylation with acetic anhydride, and the resulting acetylated compound is then converted into 3,3′-dinitro-N,N′-diacetylbenzidine by nitration. For example, this nitration is performed with concentrated nitric acid in a mixture of acetic anhydride and acetic acid. 3,3′-Dinitro-N,N′-diacetylbenzidine is treated with a base to remove the acetyl groups and then treated with tin (II) chloride in hydrochloric acid to reduce the nitro groups to yield 3,3′,4,4′-tetraaminobiphenyl (Scheme 1).

Workup

  1. customto remove the acetyl groups
  2. additiontreated with tin (II) chloride in hydrochloric acid

Sources & evidence

ORD record
ord-a0ef56b3459d450684c7015e01f86b43
Source dataset
uspto-grants-2009_10
Patent number
US07601873B2

Reaction notes

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