Dimethylformamide → (S)-2-{4-[2-(4-chlorophenyl)ethanesulfonyl]piperazin-1-ylmethyl}-2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazole

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Reaction Steps

A mixture of (S)-2-methyl-6-nitro-2-(piperazin-1-ylmethyl)-2,3-dihydroimidazo[2,1-b]oxazole dihydrochloride prepared in Example 408 (236 mg, 0.88 mmol) and DMF (3 ml) was added potassium carbonate (500 mg, 3.62 mmol) and 2-(4-chlorophenyl)ethanesulfonyl chloride (240 mg, 1 mmol) in this order followed by stirring at room temperature overnight. To the reaction mixture, water was added, and the solution was extracted with ethyl acetate. The organic phase was washed with water three times and saturated saline solution, dried over sodium sulfate and then filtered. The filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (methylene chloride/methanol=50/1) to afford (S)-2-{4-[2-(4-chlorophenyl)ethanesulfonyl]piperazin-1-ylmethyl}-2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazole (100 mg, yield 26%) as a white powder.

Provenance & Evidence