Triethylamine → HCID 57947757, compound

Temperature

0 °C

To a solution of (S)-2-(tert-butoxycarbonylamino)-6-methoxy-6-oxohexanoic acid (23.5 g, 85 mmol) in anhydrous THF (100 mL) was added Et3N (14.2 mL, 102 mmol, 1.2 equiv.). The solution was cooled down to 0° C. and isobutyl chloroformate (12.2 mL, 93.5 mmol, 1.1 equiv.) was added dropwise. The solution was stirred for 30 min. The precipitate was filtered off. The filtrate was cooled down to 0° C. and a suspension of sodium borohydride (6.5 g, 170 mmol, 2 equiv.) in H2O (3 mL) was added in one portion. The reaction was stirred for 1 h, and quenched with saturated NH4Cl. THF was removed. The residue was dissolved into EtOAc (400 mL) and extracted with saturated NH4Cl twice. The organic layers were combined, dried and concentrated. The residue was purified on silica gel column (hexanes/EtOAc 1:1) to give (S)-methyl 5-(tert-butoxycarbonylamino)-6-hydroxyhexanoate (20 g, 90%) as a colorless oil. LRMS (M-Boc+H+) m/z 162.1.

1. filtrationThe precipitate was filtered off
2. temperatureThe filtrate was cooled down to 0° C.
3. additionwas added in one portion
4. stirringThe reaction was stirred for 1 h
5. customquenched with saturated NH4Cl
6. customTHF was removed
7. dissolutionThe residue was dissolved into EtOAc (400 mL)
8. extractionextracted with saturated NH4Cl twice
9. customdried
10. concentrationconcentrated
11. customThe residue was purified on silica gel column (hexanes/EtOAc 1:1)

ORD record

ord-1a8703c52bfa41c9887b9c6ed0deb96a

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08088793B2