Acetic Anhydride → 3-[1-(4-Bromo-phenyl)-1-methyl-ethyl]-5-methyl-[1,2,4]oxadiazole

To a solution of 2-(4-bromophenyl)-2-methylpropionitrile (3 g, 13.38 mmol)) in EtOH (40 mL) was added hydroxylamine HCl (4.65 g, 66.93 mmol) and K2CO3 (9.25 g, 66.93 mmol). The reaction mixture was stirred at room temperature overnight. The resultant white precipitate was eliminated by filtration and the filtrate was concentrated to a yellow oil which was dissolved in pyridine (16 mL). Acetic anhydride (3.79 mL, 40.14 mol) was added and the reaction was stirred to reflux for 2 hours. The solution was quenched with 2N HCl (50 mL) and extracted 3 times with EtOAc (20 mL). The organics were combined, and dried with Na2SO4. The solvent was removed under reduced pressure and the residue was purified by flash chromatography (40% EtOAc in Hexanes) to yield the product as a white foam (0.88 g, 30%).

1. filtrationThe resultant white precipitate was eliminated by filtration
2. concentrationthe filtrate was concentrated to a yellow oil which
3. dissolutionwas dissolved in pyridine (16 mL)
4. stirringthe reaction was stirred
5. temperatureto reflux for 2 hours
6. customThe solution was quenched with 2N HCl (50 mL)
7. extractionextracted 3 times with EtOAc (20 mL)
8. dry with materialdried with Na2SO4
9. customThe solvent was removed under reduced pressure
10. customthe residue was purified by flash chromatography (40% EtOAc in Hexanes)

ORD record

ord-d98f38eee96c406c8978fe4e7b99a347

Source dataset

uspto-grants-2006_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07148226B2