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