Ammonium Chloride → HCID 86705542, compound

Temperature

-78 °C

To a stirred solution of freshly prepared 328 (1.2 g, 4.171 mmol) in Et2O (20 mL) cooled to −78° C. under nitrogen was added MeMgBr (2.781 mL, 8.342 mmol, 3M solution in Et2O) dropwise via syringe. The resulting suspension became viscous as the Grignard addition proceeded and eventually became unstirrable. Et2O (20 mL) was added to aid stirring and the reaction was warmed to 0° C. The reaction was stirred for 2 h at 0° C. and then poured into a stirred satd. aq. NH4Cl (50 mL) solution. The layers were separated and the aqueous phase was extracted with Et2O (1×50 mL). The combined organic extracts were washed brine (1×100 mL), dried (MgSO4), filtered and concentrated to a clear oil. The crude product was loaded onto a SiO2 column (Biotage 40M) and eluted with EtOAc/hexane (25/75). The higher Rf material was residual aldehyde. The lower Rf material was isolated and concentrated to afford 354 mg (28%) of a 5:1 mixture (330) of tert-butyl (1S,2S)-1-(3-chloro-4-fluorophenyl)-2-hydroxypropylcarbamate and tert-butyl (1S,2R)-1-(3-chloro-4-fluorophenyl)-2-hydroxypropylcarbamate as clear oil.

1. additionThe resulting suspension became viscous as the Grignard addition
2. temperaturethe reaction was warmed to 0° C
3. stirringThe reaction was stirred for 2 h at 0° C.
4. additionpoured into a stirred satd
5. customThe layers were separated
6. extractionthe aqueous phase was extracted with Et2O (1×50 mL)
7. washThe combined organic extracts were washed brine (1×100 mL)
8. dry with materialdried (MgSO4)
9. filtrationfiltered
10. concentrationconcentrated to a clear oil
11. washeluted with EtOAc/hexane (25/75)
12. customThe lower Rf material was isolated
13. concentrationconcentrated

ORD record

ord-8a65fea292a247c897bc0d88db7e6f23

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09133187B2