Water → 4-tert-butyl-N-(2-hydroxy-3-nitrophenyl)benzamide

Ref.: WO 96/11917. To a solution of 4-tert-butyl benzoic acid (0.81 g, 4.57 mmol) in CH2Cl2 (10 mL) cooled in an ice bath was added 1,1′-carbonyldiimidazole (0.94 g, 5.80 mmol). The solution was stirred for 5 min., then the bath was removed and the reaction was stirred at room temperature for 1.5 h. To a solution of 2-amino-6-nitro phenol (0.829 g, 5.38 mmol) in CH2Cl2 (40 mL) cooled in an ice bath was added the activated acid solution dropwise. The reaction was allowed to stir and gradually come to room temperature overnight. To the solution was added CH2Cl2 (50 mL) and H2O (25 mL) and the layers were separated. The aqueous layer was extracted with CH2Cl2 (2×30 mL). The combined organic layers were washed with H2O (25 mL), 1 N HCl (25 mL), and brine (25 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure. The crude material was adsorbed onto silica gel and purified by silica gel chromatography, eluting with 66% CH2Cl2/hexane to 75% CH2Cl2/hexane to afford the title compound (0.579 g) as a golden solid. MS (ESI-POS): [M+H]+=315; Anal. Calc'd for C17H18N2O4: C, 64.96; H, 5.77; N, 8.91. Found: C, 64.98; H, 5.78; N, 8.89.

1. customthe bath was removed
2. stirringthe reaction was stirred at room temperature for 1.5 h
3. additionwas added the activated acid solution dropwise
4. stirringto stir
5. waitgradually come to room temperature overnight
6. customthe layers were separated
7. extractionThe aqueous layer was extracted with CH2Cl2 (2×30 mL)
8. washThe combined organic layers were washed with H2O (25 mL), 1 N HCl (25 mL), and brine (25 mL)
9. dry with materialdried (Na2SO4)
10. filtrationfiltered
11. concentrationconcentrated under reduced pressure
12. custompurified by silica gel chromatography
13. washeluting with 66% CH2Cl2/hexane to 75% CH2Cl2/hexane

ORD record

ord-6195fd4a3bfe4ca2884a1efd88b443f2

Source dataset

uspto-grants-2009_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07531542B2