Reaction #543545

Reaction equation

3,3′-diaminobenzidine

p-toluenesulfonic acid monohydrate

→

3,3′-diaminobenzidine tetraisopropanimine

Yield 76.0%

Solvents

acetone

Conditions

Workup

1. 1
   OtherIn a 200-ml flask equipped with a Soxhlet extractor
2. 2
   Temperatureby heating
3. 3
   Temperatureunder reflux in a nitrogen atmosphere for 3 hours
4. 4
   Otheracetone was removed under reduced pressure
5. 5
   workup.DISSOLUTIONthe residue was dissolved in ethyl acetate
6. 6
   WashThe solution was washed with water and 10% aqueous sodium carbonate solution
7. 7
   Otherto remove a residual acid component
8. 8
   OtherEthyl acetate was removed from the solution under reduced pressure
9. 9
   Otherthe residue was purified by silica gel chromatography

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 0.95 g (5 mmol) of p-toluenesulfonic acid monohydrate, 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 dissolved in ethyl acetate. The solution was washed with water and 10% aqueous sodium carbonate solution to remove a residual acid component. Ethyl acetate was removed from the solution under reduced pressure, and the residue was purified by silica gel chromatography to yield 28.5 g (76 mmol) of the target 3,3′-diaminobenzidine tetraisopropanimine [N,N′,N″,N′″-tetraisopropylidene-3,4,3′,4′-biphenyltetramine] in a yield of 76%.

Source