Acetic Acid → 3,3'-Diaminobenzidine monoisopropanimine

Reaction equation

[NH2:1][C:2]1[CH:3]=[C:4]([C:9]2[CH:15]=[CH:14][C:12]([NH2:13])=[C:11]([NH2:16])[CH:10]=2)[CH:5]=[CH:6][C:7]=1[NH2:8].C(O)(=O)C>CC(C)=O>[C:2](=[NH:1])([CH3:3])[CH3:7].[NH2:1][C:2]1[CH:3]=[C:4]([C:9]2[CH:15]=[CH:14][C:12]([NH2:13])=[C:11]([NH2:16])[CH:10]=2)[CH:5]=[CH:6][C:7]=1[NH2:8].[C:2](=[NH:1])([CH3:3])[CH3:7].[C:2](=[NH:1])([CH3:3])[CH3:7].[NH2:1][C:2]1[CH:3]=[C:4]([C:9]2[CH:15]=[CH:14][C:12]([NH2:13])=[C:11]([NH2:16])[CH:10]=2)[CH:5]=[CH:6][C:7]=1[NH2:8]

Participants

Procedure

In a 200-ml flask equipped with a Soxhlet extractor including molecular sieves 4A as a dehydrating agent, a stirrer, a condenser and a thermometer were placed 21.4 g (100 mmol) of 3,3′-diaminobenzidine, 100 ml of acetone and 3.0 g (50 mmol) of acetic acid, followed by heating under reflux in a nitrogen atmosphere for 3 hours. After cooling to room temperature, acetone was removed under reduced pressure, and the residue was purified by silica gel chromatography to yield 16.5 g (65 mmol) of 3,3′-diaminobenzidine monoisopropanimine [N′-isopropylidene-3,4,3′,4′-biphenyltetramine] and 4.7 g (16 mmol) of 3,3′-diaminobenzidine diisopropanimine [N′,N′″-diisopropylidene-3,4,3′,4′-biphenyltetramine].