反应详情

A mixture of p-dimethylaminophenyl magnesium bromide (1 mole) and thallous bromide (2 moles) is stirred and refluxed under nitrogen for 5 hours. The cooled solution is filtered to remove thallium, and hydrogen chloride passed into the filtrate. The colorless hydrochloride which precipitates is filtered off, stirred into dilute sodium hydroxide, and the tetramethylbenzidine extracted with ether-benzene (1:1, 2 × 30 ml.) The extracts are dried over anhydrous sodium sulfate and the solvent removed to leave a yellow solid which is sublimed at 165°/0.05 mm. to give a 70% yield of pure N,N,N',N'-tetramethylbenzidine as a colorless solid, m.p. 195°.

1. temperaturerefluxed under nitrogen for 5 hours
2. filtrationThe cooled solution is filtered
3. customto remove thallium, and hydrogen chloride
4. customThe colorless hydrochloride which precipitates
5. filtrationis filtered off
6. extractionthe tetramethylbenzidine extracted with ether-benzene (1:1, 2 × 30 ml.) The extracts
7. dry with materialare dried over anhydrous sodium sulfate
8. customthe solvent removed
9. customto leave a yellow solid which
10. customis sublimed at 165°