Allyl bromide → 1-allyl-6-chloro-2-ethyl-1H-imidazo[4,5-b]quinoxaline

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Reaction Steps

A mixture of 75 parts of 6-chloro-2-ethyl-1H-imidazo[4,5-b]quinoxaline, 85 parts of thallous ethoxide, and 600 parts of 2:1 anhydrous dimethylformamide-tetrahydrofuran was stirred at room temperature for 1 hour. Allyl bromide (50 parts) was added in one portion, and the mixture was stirred for an additional hour, followed by heating for 30 minutes on a steam bath. The mixture was filtered, and the filtrate was diluted with 2000 parts of water. The filtrate was extracted with three 500 -part portions of chloroform, and the combined extracts dried (potassium carbonate) and evaporated in vacuo. The residue was dissolved in 500 parts of benzene and decolorized (silica gel). The benzene was removed in vacuo and the crude product recrystallized from 95:5 ether-ethanol to yield 24 parts of 1-allyl-6-chloro-2-ethyl-1H-imidazo[4,5-b]quinoxaline, m.p. 117°-121°.

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