반응 #421654

반응 방정식

NaCNBH3

HOAc

5-bromopyridin-3-amine

acetone

→

5-bromo-N-isopropylpyridin-3-amine

용매

MeOH

반응 조건

후처리

1. 1
   workup.STIRRINGstirred at room temperature overnight
2. 2
   기타The MeOH was removed under vacuum
3. 3
   기타the residue was partitioned between EtOAc and saturated aqueous NaHCO3
4. 4
   건조The organic layer was dried over MgSO4
5. 5
   기타evaporated under vacuum
6. 6
   기타The crude product was purified on a silica gel column (100% hexane→90:10 hexane:EtOAc)

실험 절차

To a solution of 5-bromopyridin-3-amine (XXV) (535 mg, 3.09 mmol) in MeOH (62 mL) was added acetone (296 μL, 4.02 mL). The pH was adjusted to 4 using HOAc and stirred for 30 min. NaCNBH3 (272 mg, 4.33 mmol) was added and stirred at room temperature overnight. The MeOH was removed under vacuum and the residue was partitioned between EtOAc and saturated aqueous NaHCO3. The organic layer was dried over MgSO4 and evaporated under vacuum. The crude product was purified on a silica gel column (100% hexane→90:10 hexane:EtOAc) to produce 5-bromo-N-isopropylpyridin-3-amine (XLVI) as an oil which slowly solidified into an off-white solid (309 mg, 1.44 mmol, 47% yield). 1H NMR (DMSO-d6, 500 MHz) δ ppm 1.12 (d, J=6.3 Hz, 6H), 3.55-3.59 (m, 1H), 6.03 (d, J=7.9 Hz, 1H), 7.05-7.06 (m, 1H), 7.75 (d, J=2 Hz, 1H), 7.90 (d, J=2 Hz, 1H); ESIMS found C8H11BrN2 m/z 215 (M+H).

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