Réaction #421654

Équation de réaction

NaCNBH3

HOAc

5-bromopyridin-3-amine

acetone

→

5-bromo-N-isopropylpyridin-3-amine

Solvants

MeOH

Conditions de réaction

Traitement

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

Mode opératoire

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).

Source