反应详情

In a 3 L, one-necked flask (equipped with a magnetic stir bar and a condenser with nitrogen inlet) was charged (S)-[1-(2,2-dimethyl-4,6-dioxo-[1,3]dioxan-5-ylmethyl)-2-methyl-propyl]-carbamic acid, tert-butyl ester prepared in Step B above (147 g, 0.446 mol) and toluene (1.4 L). The reaction mixture was heated to reflux for 4 h then cooled to room temperature and concentrated in vacuo to yield crude product as a residual oil. The crude product was dissolved in heptane (˜200 mL) and loaded onto a Biotage 75 L (800 g silica gel) and eluted with heptanes (1 L), 1:9 (7 L), and 1:3 ethyl acetate-heptane (2 L) to yield the product as an oil.

1. customIn a 3 L, one-necked flask (equipped with a magnetic stir bar and a condenser with nitrogen inlet)
2. temperatureThe reaction mixture was heated
3. temperatureto reflux for 4 h
4. concentrationconcentrated in vacuo
5. customto yield crude product as a residual oil
6. washeluted with heptanes (1 L), 1:9 (7 L), and 1:3 ethyl acetate-heptane (2 L)