Tetrahydrofuran → Phenyl 5-tert-butyl-2-methoxy-3-(methylsulfonamido)phenylcarbamate

Participants

Reaction Steps

Under N2 was charged the product of step (ix) above (167.0 g, 613 mmol), NaHCO3 (77.3 g, 920 mmol), THF (870 mL) and DCM (1440 mL). Phenyl chloroformate (82.6 mL, 659 mmol) was added dropwise, while maintaining the temperature below 20° C., and the reaction was stirred at room temperature for 4 h. HPLC analysis of the reaction mixture indicated 98.6% product and 0.03% starting material. The reaction mixture was filtered and the cake was washed with THF (˜50 mL). The filtrate was concentrated to ˜900 mL and cyclohexane (2400 mL) was added, then the mixture was left to stir overnight. The resulting solid was collected via vacuum filtration and washed with cyclohexane (500 mL). The pale pink solid produced was dried, under vacuum, at 40° C. for 4 h. Yield=232.6 g (96.7%). HPLC purity 94.5%. 1H NMR purity >95%.

Provenance & Evidence