反应详情

To a solution of 3-(5-(azetidin-3-yl)pyridin-2-ylamino)-5-bromo-1-methylpyridin-2(1H)-one 155n (crude, 4.6 mmol) in methanol (50 mL) and acetic acid (5 mL) at 0° C., was added CH3CHO (40% wt in H2O) (10 g, 92 mmol) followed by the addition of NaBH(CH3O)3 (20 g, 92 mmol) in small portions over a period of 1 h. After the reaction was finished, the mixture was adjusted to pH>7 with 2N NaOH. Then the mixture was extracted with DCM (80 mL×3), dried over Na2SO4 and concentrated to get a yellow solid, which was purified on flash column eluting with 50:1 DCM/MeOH containing 0.5% Et3N to afford 250a as a yellow solid (43%, two steps). LCMS: (M+H)+ 364. 1H NMR (500 MHz, DMSO) δ 8.72 (s, 1H), 8.66 (d, J=3, 1H), 8.21 (d, J=3, 1H), 7.68 (dd, J=9, 1H), 7.52 (d, J=2.5, 1H), 7.32 (d, J=9, 1H), 3.54 (m, 6H), 2.99 (m, 2H), 2.42 (m, 2H), 0.89 (t, J=7, 3H).

1. extractionThen the mixture was extracted with DCM (80 mL×3)
2. dry with materialdried over Na2SO4
3. concentrationconcentrated
4. customto get a yellow solid, which
5. customwas purified on flash column
6. washeluting with 50:1 DCM/MeOH containing 0.5% Et3N