4-Toluenesulfonyl chloride → (S)-2-((tert-Butoxycarbonyl)amino)-3-phenylpropyl 4-methylbenzenesulfonate

Temperature

0 °C

The recovered intermediate (20a) (8.5 g, 33 mmol, 1.0 eq) was dissolved into 70 mL pyridine containing potassium hydroxide (2.1 g, 37 mmol, 1.1 eq) and the mixture was chilled in an ice bath. Tosyl chloride (7.1 g, 37 mmol, 1.1 eq) was added and the mixture was stirred at 0° C. for 2 hours then refrigerated overnight. The mixture was filtered and the filtrate was concentrated under reduced pressure. The recovered residue was dissolved into 300 mL EtOAc, washed with 2×200 mL 1M H3PO4, saturated bicarbonate, and saturated aqueous NaCl. The organic was dried over MgSO4 and concentrated under reduced pressure to yield intermediate (20b) (10.3 g) as a pale brown oil.

1. temperaturethe mixture was chilled in an ice bath
2. waitthen refrigerated overnight
3. filtrationThe mixture was filtered
4. concentrationthe filtrate was concentrated under reduced pressure
5. dissolutionThe recovered residue was dissolved into 300 mL EtOAc
6. washwashed with 2×200 mL 1M H3PO4, saturated bicarbonate, and saturated aqueous NaCl
7. dry with materialThe organic was dried over MgSO4
8. concentrationconcentrated under reduced pressure

ORD record

ord-2dbc20ae0f4f4784a5cefad32b5af65f

Source dataset

uspto-grants-2014_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08664254B2