تفاعل #421654

معادلة التفاعل

NaCNBH3

HOAc

5-bromopyridin-3-amine

acetone

→

5-bromo-N-isopropylpyridin-3-amine

المذيبات

MeOH

ظروف التفاعل

المعالجة

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

الإجراء التجريبي

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).

المصدر