(3S)-4-(benzyloxy)-3-(((tert-butoxy)carbonyl)amino)-4-oxobutanoic acid → Boc-L-Homoser-Obzl

Temperature

0 °C

(S)-2-tert-Butoxycarbonylamino-succinic acid 1-benzyl ester (2.62 g, 8.10 mmol) under an atmosphere of nitrogen was dissolved in THF (40 mL) and cooled to 0° C. A 1.0 M borane-THF complex in THF (15 mL) was added dropwise and the reaction mixture was stirred for 3 h, quenched carefully with MeOH (20 mL) and stirred for 20 min. The reaction mixture was treated with MeOH (2×15 mL) and concentrated to dryness. The residue was dissolved in EtOAc and washed with 1N HCl (10 mL), saturated sodium bicarbonate (10 mL), and brine (10 mL). The organic extract was dried over sodium sulfate, filtered and purified on SiO2 to give the intermediate (S)-2-tert-butoxycarbonylamino-4-hydroxy-butyric acid benzyl ester as a clear colorless oil (1.2 g), which was used in the procedure of Preparation 14 to prepare the title compound.

1. customquenched carefully with MeOH (20 mL)
2. stirringstirred for 20 min
3. additionThe reaction mixture was treated with MeOH (2×15 mL)
4. concentrationconcentrated to dryness
5. dissolutionThe residue was dissolved in EtOAc
6. washwashed with 1N HCl (10 mL), saturated sodium bicarbonate (10 mL), and brine (10 mL)
7. extractionThe organic extract
8. dry with materialwas dried over sodium sulfate
9. filtrationfiltered
10. custompurified on SiO2

ORD record

ord-fc783a5e11ee486b85489ac41f2ec668

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08952031B2