Sodium Carbonate → chloromethyl (2S)-2-(((tert-butoxy)carbonyl)amino)-3-methylbutanoate

To a vigorously stirred mixture of (S)-2-((tert-butoxycarbonyl)amino)-3-methylbutanoic acid (4 g, 18.41 mmol), tetrabutylammonium hydrogen sulfate (1.25 g, 3.68 mmol), and Na2CO3 (9.76 g, 92 mmol) in DCM 80 (mL) and water (80 mL), cooled in an ice/water bath, was slowly added chloromethyl chlorosulfate (3.8 mL, 36.8 mmol) over 4 min. After stirring in the ice/water bath for 30 min, the cold bath was removed and the reaction mixture was allowed to stir at room temperature. After stirring 16 h at room temperature, the reaction mixture was diluted with water and extracted with DCM. The aqueous layer was back extracted with DCM and the combined organic layers were dried over MgSO4, filtered and concentrated to afford Intermediate 38A (5.45 g).

1. temperaturecooled in an ice/water bath
2. customover 4 min
3. customthe cold bath was removed
4. stirringAfter stirring 16 h at room temperature
5. additionthe reaction mixture was diluted with water
6. extractionextracted with DCM
7. extractionThe aqueous layer was back extracted with DCM
8. dry with materialthe combined organic layers were dried over MgSO4
9. filtrationfiltered
10. concentrationconcentrated

ORD record

ord-5342d37585c348d587120ba7bde87248

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09273014B2