3-Nitrobenzaldehyde → 4-Methyl-5-(3-nitrophenyl)-1,3-oxazole

To a cooled (0° C.) solution of 3-{[1-(isocyanoethyl)ethyl]sulfonyl}aniline (60 g, 0.287 mol) in dry MeOH (800 mL), was added dry powdered K2CO3 and stirred at rt for 1 h. The reaction mixture was re-cooled to 0° C. and 3-nitro benzaldehyde (43 g, 0.287 mol) added. The reaction mixture was warmed to rt, followed by heating at 55° C. overnight with stirring. The excess solvent was removed under reduced pressure, the residue was dissolved in water (100 mL) and extracted with EtOAc (3×350 mL). The combined organic layers were washed with brine, water, dried over anhydrous Na2SO4 and concentrated. The crude product was purified by silica get (60-120 mesh) column chromatograph using 15% EtOAc in petroleum-ether to yield product as yellow solid. Yield 50 g (86%).

1. additionwas added
2. dry with materialdry powdered K2CO3
3. temperatureThe reaction mixture was re-cooled to 0° C.
4. temperatureThe reaction mixture was warmed to rt
5. temperatureby heating at 55° C. overnight
6. stirringwith stirring
7. customThe excess solvent was removed under reduced pressure
8. dissolutionthe residue was dissolved in water (100 mL)
9. extractionextracted with EtOAc (3×350 mL)
10. washThe combined organic layers were washed with brine, water
11. dry with materialdried over anhydrous Na2SO4
12. concentrationconcentrated
13. customThe crude product was purified by silica
14. customget (60-120 mesh) column chromatograph
15. customto yield product as yellow solid

ORD record

ord-cce35d9969ce45f4bea544002a4ced17

Source dataset

uspto-grants-2010_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07807673B2