反应详情

2-(6-Bromo-naphthalen-2-yl)-2-nitro-propane-1,3-diol (32.6 g, 0.100 mol) was dissolved in methylene chloride (150 mL, 2.3 mol; Acros, anhydrous) and 2,2-dimethoxypropane (180 mL, 1.5 mol; Aldrich), cooled with an ice bath. Boron trifluoride etherate (10.1 mL, 0.0800 mol; Aldrich) was added slowly. The mixture was stirred for 15 min and large amount of solid precipitated. The cooling bath was removed and the mixture was stirred at r.t. for 4 hours. The mixture was quenched with aqueous saturated NaHCO3 (˜600 mL) to pH˜8, extracted with EtOAc (600 mL, 300 mL, 2×100 mL). The EtOAc layer was washed with water, brine, dried over Na2SO4, filtered. The solvent was evaporated to ˜100 mL. The resulted solid product was collected by filtration and the mother liquid was concentrated further to afford the second crop of product. Rf of product=0.4(EtOAc/hexane=1/4). Total product weighed 30.0 g (yield 82%).

1. customlarge amount of solid precipitated
2. customThe cooling bath was removed
3. stirringthe mixture was stirred at r.t. for 4 hours
4. customThe mixture was quenched with aqueous saturated NaHCO3 (˜600 mL) to pH˜8
5. extractionextracted with EtOAc (600 mL, 300 mL, 2×100 mL)
6. washThe EtOAc layer was washed with water, brine
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. customThe solvent was evaporated to ˜100 mL
10. filtrationThe resulted solid product was collected by filtration
11. concentrationthe mother liquid was concentrated further
12. customto afford the second crop of product