Sodium borohydride → (2S)-4-methyl-2-(isobutylamino)pentanol

To a solution of (4 g)-2-isopropyl-4-isobutyl-1,3-oxazolidine (223g, 1.3 mol) in EtOH (1.1 L) cooled to −13° C. with an ice/MeOH bath was added NaBH4 (70.3 g, 1.82 mol) in portions at such a rate that the reaction temp. did not exceed 10° C. (approximately 2 h). The reaction mixture was allowed to warm to room temp., stirred overnight, then filtered through a coarse sintered glass funnel. The resulting solids were washed with EtOH. The combined filtrate was concentrated under reduced pressure and the residue was treated with EtOAc (2 L) and water (1 L). The organic layer was dried (Na2SO4) and concentrated under reduced pressure to yield (2S)-4-methyl-2-(isobutylamino)pentan-1-ol as a viscous pale yellow oil (192 g, 85%): 1H NMR (CDCl3) δ0.90-0.96 (m, 12H), 1.18-1.24 (m, 1H), 1.32-1.39 (m, 1H), 1.58-1.72 (m, 2H), 2.33 (dd, J=11.1, 7.0 Hz, 1H), 2.49 (dd, J=11.1, 7.0 Hz, 1H), 2.61-1.67 (m, 1H), 3.19 (dd, J=10.3, 6.2 Hz, 1H), 3.60 (dd, J=10.3, 6.2 Hz, 1H).

1. customdid not exceed 10° C.
2. custom(approximately 2 h)
3. temperatureto warm to room temp.
4. filtrationfiltered through a coarse sintered glass funnel
5. washThe resulting solids were washed with EtOH
6. concentrationThe combined filtrate was concentrated under reduced pressure
7. additionthe residue was treated with EtOAc (2 L) and water (1 L)
8. dry with materialThe organic layer was dried (Na2SO4)
9. concentrationconcentrated under reduced pressure

ORD record

ord-bb64f49959e0400da318c2355a18f38a

Source dataset

uspto-grants-2002_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06353006B1