Methyl chloroformate → Tert-butyl (s)-(1-hydroxypent-4-en-2-yl)carbamate

To a solution of (S)-2-(tert-butoxycarbonylamino)pent-4-enoic acid (166 g, 0.77 mol) and Et3N (214 mL) in THF (2.5 L) was added methyl chloroformate (71.2 mL, 0.93 mol) at 0-5° C. The reaction mixture was stirred for 15 min and filtered to remove TEA salt. To the filtrate was added a solution of NaBH4 (60 g, 1.54 mol) in a small amount of water at 0-5° C. The reaction was stirred at RT for 1 h and quenched with saturated NH4Cl solution. The reaction mixture was concentrated to remove most of THF and extracted with EtOAc (700 mL×3). The organic layers were washed with water, NaOH (1 N) and brine, dried over Na2SO4, and concentrated to give (S)-tert-butyl 1-hydroxypent-4-en-2-ylcarbamate (165 g), which was used without further purification. LRMS (M+H+) m/z 202.1.

1. filtrationfiltered
2. customto remove TEA salt
3. stirringThe reaction was stirred at RT for 1 h
4. customquenched with saturated NH4Cl solution
5. concentrationThe reaction mixture was concentrated
6. customto remove most of THF
7. extractionextracted with EtOAc (700 mL×3)
8. washThe organic layers were washed with water, NaOH (1 N) and brine
9. dry with materialdried over Na2SO4
10. concentrationconcentrated

ORD record

ord-5cc93d8394de4b7cadbfd6c235d257a5

Source dataset

uspto-grants-2014_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08759374B2