Dimethylformamide → HCID 86586415, compound

Temperature

0 °C

(2R)-3-methyl-2-[(2-propylthiobenzoxazol-6-sulfonyl)amino]butanoic acid (112 mg, 0.3 mmol) prepared in Example 19 was dissolved in dichloromethane (2 mL) and cooled down to 0° C., and, oxalylchloride (0.08 mL, 3 equi.) and DMF of catalytic amount were added. After the reaction was completed, the reaction solution was distilled under reduced pressure to remove the solvent and dried under reduced pressure. Then, (2R)-3-methyl-2-[(2-propylthiobenzoxazol-6-sulfonyl)amino]butanoic chloride thus obtained was dissolved in THF (1 mL). Hydroxylamine hydrochloride (0.21 g, 10 equi.) and NaHCO3 (0.303 g, 12 equi.) was dissolved in THF/H2O (2 mL/2 mL) and cooled down to 0° C. to prepare a hydroxylamine solution. Then, acid chloride THF solution was slowly added to the hydroxylamine solution while maintaining the temperature of 0° C. After 1 hour, the solvent was removed from the reaction solution. Then, the product was extracted with ethylacetate (5 mL), washed with H2O and 0.1N HCl and dried over MgSO4. The dried material was distilled under reduced pressure and vacuum-dried to prepare the titled compound, (2R)-N-hydroxy-3-methyl-2-[(2-propylthiobenzoxazol-6-sulfonyl)amino]butyric amide (100 mg, 85%).

1. distillationthe reaction solution was distilled under reduced pressure
2. customto remove the solvent
3. customdried under reduced pressure

ORD record

ord-c6222acf9c354dff8849d9761bda0724

Source dataset

uspto-grants-2003_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06548667B2