反应详情

A 25 mL round bottom flask equipped with a magnetic stir bar was charged with 0.412 g (1.73 mmol) of the product of Step D dissolved in 6 mL of methylene chloride. To the reaction mixture was added 0.451 g (2.35 mmol) of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, 0.318 g (2.35 mmol) of 1-hydroxybenzotriazole, 0.518 μL (4.71 mmol) of N-methylmorpholine, followed by 0.520 g (1.57 mmol) of 4-cyclohexyl-4-[(4,4-dimethyl-2-oxo-1,3-oxazolidin-3-yl)methyl]piperidinium chloride. The resulting clear yellow solution was stirred at room temperature for 48 h, then was partitioned between methylene chloride and saturated aqueous sodium bicarbonate. The organic layer was separated, washed with 1 N hydrochloric acid, saturated aqueous sodium bicarbonate, brine, then dried (Na2SO4), filtered and evaporated in vacuo. The residual oil was purified on a Biotage Flash 40i chromatography apparatus (40 g Flash 40S silica gel cartridge) eluted sequentially with hexane for 2 min, 30% ethyl acetate-hexanes for 2 min and finally 75% ethyl acetate-hexanes for 20 min. Evaporation of the purified fractions and drying in vacuo afforded the title compound.

1. customA 25 mL round bottom flask equipped with a magnetic stir bar
2. customwas partitioned between methylene chloride and saturated aqueous sodium bicarbonate
3. customThe organic layer was separated
4. washwashed with 1 N hydrochloric acid, saturated aqueous sodium bicarbonate, brine
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. customevaporated in vacuo
8. customThe residual oil was purified on a Biotage Flash 40i chromatography apparatus (40 g Flash 40S silica gel cartridge)
9. washeluted sequentially with hexane for 2 min
10. wait30% ethyl acetate-hexanes for 2 min
11. waitfinally 75% ethyl acetate-hexanes for 20 min
12. customEvaporation of the purified fractions
13. customdrying in vacuo