Diisopropylethylamine → (R)-3-(2-chloro-4-nitroimidazol-1-yl)-2-hydroxy-2-methylpropyl 4-tert-butoxycarbonylpiperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

(R)-2-Chloro-1-(2,3-dihydroxy-2-methylpropyl)-4-nitroimidazole prepared in Example 10 (4.43 g, 18.79 mmol), N,N-diisopropylethylamine (4.68 ml, 26.84 mmol) and 4-dimethylaminopyridine (0.33 g, 2.68 mmol) were added to a suspension of tert-butyl 4-chlorocarbonylpiperazine-1-carboxylate (3.34 g, 13.42 mmol) in toluene (70 ml), and the resulting mixture was stirred at 100° C. for 4.5 hours. The reaction mixture was diluted with ethyl acetate, washed with water, dried over magnesium sulfate and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (n-hexane/methylene chloride/ethyl acetate=45/45/10) to afford (R)-3-(2-chloro-4-nitroimidazol-1-yl)-2-hydroxy-2-methylpropyl 4-tert-butoxycarbonylpiperazine-1-carboxylate (4.12 g, yield 69%) as a colorless oil.

Provenance & Evidence