反应详情

Acetic anhydride (16.6 g, 162.8 mmol) is added to a solution of Compound 1.14 (33.0 g, 108.55 mmol) in pyridine (150 mL) at 0° C. under an inert atmosphere. The resulting reaction mixture is stirred overnight at ambient temperature. Upon completion of the reaction, as evidenced by TLC, pyridine and remaining acetic anhydride are removed under vacuum. The crude residue is diluted with ethyl acetate (500 mL) and washed with water (3×150 mL), saturated brine solution (100 mL) and dried over MgSO4 (75 g). The solvent is evaporated under vacuum and the crude material is purified by column chromatography [59(W)×800(L) mm, 60-120 Mesh silica, 150 g], eluting with ethyl acetate/hexane (1:10) [25 mL fractions, 10 mL/min elution, monitored by TLC with p-anisaldehyde charring; Rf for Compound 1.15=0.38 and Rf for Compound 1.14=0.1 in EtOAc/Hexane (3:7)] to afford Compound 1.15 (19.0 g, 66.4% yield) as a colorless solid. Table 4 describes the measured properties of the product.

1. customThe resulting reaction mixture
2. customUpon completion of the reaction
3. customare removed under vacuum
4. additionThe crude residue is diluted with ethyl acetate (500 mL)
5. washwashed with water (3×150 mL), saturated brine solution (100 mL)
6. dry with materialdried over MgSO4 (75 g)
7. customThe solvent is evaporated under vacuum
8. customthe crude material is purified by column chromatography [59(W)×800(L) mm, 60-120 Mesh silica, 150 g]
9. washeluting with ethyl acetate/hexane (1:10) [25 mL fractions, 10 mL/min elution, monitored by TLC with p-anisaldehyde charring; Rf for Compound 1.15=0.38 and Rf for Compound 1.14=0.1 in EtOAc/Hexane (3:7)]