tert-Butanol → 4-{2-[(3-Bromo-4-chloro-benzoyl)-methyl-amino]-phenyl}-butyric acid tert-butyl ester

To a cooled solution (0° C.) of 4-{2-[(3-bromo-4-chloro-benzoyl)-methyl-amino]-phenyl}-butyric acid (1.07 g, 2.60 mmol) in anhydrous DCM (10 mL), oxalyl chloride (0.34 mL, 3.90 mmol) was added dropwise. The mixture was stirred at room temperature for 4 hours, concentrated in vacuo and redissolved in anhydrous dichloromethane (5 mL). A solution of t-butanol (960 mg, 13 mmol) in anhydrous DCM (5 mL) was added and the mixture was stirred at room temperature overnight. After dilution with DCM, the mixture was washed with sat NaHCO3 and brine, dried over Na2SO4, filtered and concentrated. Purification by silica gel column chromatography (EtOAc/Hexanes: 1/4 with gradient up to EtOAc/Hexanes 1/3) afforded 1.1 g of 4-{2-[(3-bromo-4-chloro-benzoyl)-methyl-amino]-phenyl}-butyric acid tert-butyl ester as a colorless oil. MS [M+H]+ (fragment): 411.7 (f; tR=3.10 min, (method 1)

1. concentrationconcentrated in vacuo
2. dissolutionredissolved in anhydrous dichloromethane (5 mL)
3. stirringthe mixture was stirred at room temperature overnight
4. washAfter dilution with DCM, the mixture was washed with sat NaHCO3 and brine
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated
8. customPurification by silica gel column chromatography (EtOAc/Hexanes: 1/4 with gradient up to EtOAc/Hexanes 1/3)

ORD record

ord-0461030dd82e4f149c46c232e61d18b6

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08952161B2