(2S,3S)-4,4,4-Trifluoro-2-hydrazino-3-methyl-butan-1-ol HCl → (2S,3S)-2-Amino-4,4,4-trifluoro-3-methyl-butan-1-ol HCl

(2S,3S)-4,4,4-Trifluoro-2-hydrazino-3-methyl-butan-1-ol HCl (130 g, 0.623 mole) was dissolved in 1.4 L MeOH with 60 mL concentrated HCl. The solution was hydrogenated with 10 g PtO2 at 50 psig for 12 hours. The mixture was filtered and the filter washed with 1 L MeOH. The MeOH was removed to dryness under vacuum at 30-40° C. The solid was chased with two portions of 1 L MeOH. The solid was stirred with 0.5 L MeOH for 1 hour and the NH4Cl was removed by filtration. To remove more NH4Cl, the filtrate can be concentrated to ⅔ volume and crystallized NH4Cl removed by filtration. The filtrate was concentrated to dryness and dried at 35° C. at <10 mm Hg. The hydrochloride can be purified by stirring with 20% v/v CH3CN: EtOAc removing a green coloring and removing essentially all the Pt to the 10 ppm level.

1. filtrationThe mixture was filtered
2. washthe filter washed with 1 L MeOH
3. customThe MeOH was removed to dryness under vacuum at 30-40° C
4. customthe NH4Cl was removed by filtration
5. customTo remove more NH4Cl
6. concentrationthe filtrate can be concentrated
7. customcrystallized NH4Cl
8. customremoved by filtration
9. concentrationThe filtrate was concentrated to dryness
10. customdried at 35° C. at <10 mm Hg
11. customThe hydrochloride can be purified
12. stirringby stirring with 20% v/v CH3CN
13. customEtOAc removing a green coloring and removing essentially all the Pt to the 10 ppm level

ORD record

ord-bda13d8f298646e59afe23ec36bd6b1c

Source dataset

uspto-grants-2010_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07737303B2