Triethylamine → 3,5-dichlorobenzyl (S)-4-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperazine-1-carboxylate

참여 물질

반응 단계

To a mixture of (S)-2-methyl-6-nitro-2-(piperazin-1-ylmethyl)-2,3-dihydroimidazo[2,1-b]oxazole dihydrochloride prepared in Example 408 (300 mg, 0.88 mmol) and DMF (3 ml), triethylamine (270 mg, 2.67 mmol) was added for neutralization. To the solution, a mixture of 3,5-dichlorobenzyl alcohol (180 mg, 1.02 mmol), DMF (3 ml) and 1,1′-carbonyldiimidazole (180 mg, 1.11 mmol) stirred at room temperature for 2 hours was added followed by stirring at room temperature overnight. To the reaction mixture, water was added, and the mixture was extracted with ethyl acetate twice. The organic phases were combined, washed with water twice and a saturated saline solution, dried over sodium sulfate and then filtered. The filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (ethyl acetate) to afford 3,5-dichlorobenzyl (S)-4-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperazine-1-carboxylate (220 mg, yield 53%) as a white powder.

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