9
38
R. Borah and A. J. Thakur
vigorously for the specified reaction period and diluted with water (15 ml) for
complete precipitation of the product. The product was filtered in vacuum and
washed with water. Similarly, treatment of 1 mmol of imidazole with 3 mmol
of TEATB in a mixture of 2 mmol of CaCO and CH Cl –MeOH as solvent
3
2
2
afforded 2,4,5-tribomoimidazole in 45% yield.
In the case of a polycyclic aromatic compound, TEATB was added to the
solution of aromatic compound (5 ml) in acetic acid with a suitable proportion
of molar ratio. The reaction mixture was stirred at room temperature for the
specified time, during which the orange color of the mixture disappeared,
and was then diluted with water. The aqueous solution was extracted with
ether. The organic layer was separated, washed with water and aqueous
NaHCO solution, and dried over anhydrous sodium sulfate. The solvent
3
ether was evaporated under reduced pressure. For anthracene, products were
precipitated from the reaction mixture on dilution with water and then
isolated by filtration.
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(
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