反应详情

A mixture of 5-(3-Methyl-2-oxo-2,3-dihydro-benzooxazol-5-yl)-pyridine-3-carbaldehyde (51 mg, 0.2 mmol), ethanesulfonamide (33 mg, 0.3 mmol), Ti(OiPr)4 (118 uL, 114 mg, 0.4 mmol) in toluene (5 mL) was heated to reflux for overnight. After concentration, the residue was dissolved into CH2Cl2 (5 mL). NaBH(OAc)3 (127 mg, 0.6 mmol) was added at room temperature. The resulting mixture was stirred for 4 h at this temperature. Saturated NaHCO3 solution was added, and the mixture was extracted with CH2Cl2. The combined extracts were dried over anhydrous Na2SO4. After filteration and concentration, the residue was purified by flash column (MeOH—CH2Cl2, v/v, 1-3.5%) and afforded the title product (50 mg), ESI-MS m/z: 348.0 [M+1]+, Retention time 1.01 min; 1HNMR (CDCl3, 400.342 MHz) δ 1.40 (t, J=7.4 Hz, 3H), 3.07 (q, J=7.4 Hz, 2H), 3.48 (s, 3H), 4.42 (d, J=6 Hz, 2H), 4.60 (t, J=6 Hz, 1H), 7.13 (s, 1H), 7.31 (s, 2H), 7.92 (s, 1H), 8.57 (d, J=14 Hz, 1H), 8.77 (d, J=1.4 Hz, 1H).

1. temperaturewas heated
2. temperatureto reflux for overnight
3. concentrationAfter concentration
4. dissolutionthe residue was dissolved into CH2Cl2 (5 mL)
5. extractionthe mixture was extracted with CH2Cl2
6. dry with materialThe combined extracts were dried over anhydrous Na2SO4
7. concentrationAfter filteration and concentration
8. customthe residue was purified by flash column (MeOH—CH2Cl2, v/v, 1-3.5%)