反应详情

The intermediate, 6-(benzyloxy)-3,4-dihydronaphthalen-2-ylboronic acid, from previous step was dissolved in ethanol (400 mL, 7 mol). 1,3-Dihydroxy-2-propanone (6.22 g, 0.0690 mol) was added followed by benzylamine (7.54 mL, 0.0690 mol). The solution turned into a yellow suspension in 1 min. The mixture was stirred at r.t. for 2 hours under an atmosphere of nitrogen. The mixture was filtered. The filtrate was concentrated and the residue was dissolved in EtOAc/MeOH (300 mL/30 mL), washed with saturated NaHCO3/water (50 mL/50 mL) and the aqueous layer was extracted with EtOAc (2×50 mL). The combined organic layers were washed with water (50 mL), brine, dried with Na2SO4, filtered, concentrated and dried in high vacuum to give a red-brown solid product as the first crop. The collected solid was dissolved in DCM-MeOH (50 ml/50 mL) and stirred at r.t. overnight under an atmosphere of nitrogen. The solution was concentrated. The residue was treated as the first crop with EtOAc-MeOH-aqueous NaHCO3 to afford the second crop of product (4.40 g, 15%). 1H NMR (CHLOROFORM-d) δ: 6.98-7.66 (m, 13H), 6.77 (br. s., 1H), 5.05 (br. s., 2H), 3.75-4.21 (m, 6H), 2.78 (m, 2H), 1.88-2.54 (m, 2H). MS (M+1): 416.0.

1. filtrationThe mixture was filtered
2. concentrationThe filtrate was concentrated
3. dissolutionthe residue was dissolved in EtOAc/MeOH (300 mL/30 mL)
4. washwashed with saturated NaHCO3/water (50 mL/50 mL)
5. extractionthe aqueous layer was extracted with EtOAc (2×50 mL)
6. washThe combined organic layers were washed with water (50 mL), brine
7. dry with materialdried with Na2SO4
8. filtrationfiltered
9. concentrationconcentrated
10. customdried in high vacuum
11. customto give a red-brown solid product as the first crop
12. stirringstirred at r.t. overnight under an atmosphere of nitrogen
13. concentrationThe solution was concentrated
14. additionThe residue was treated as the first crop with EtOAc-MeOH-aqueous NaHCO3