Triethylamine → 1-(3-Phenyl-1,2-oxazol-4-yl)ethan-1-one

Temperature

5 °C

To a mixture of (E)- and/or (Z)-N-hydroxy-benzenecarboximidoyl chloride (7.41 g, 48 mmol) and 4-methoxy-3-buten-2-one (4.77 mL, 48 mmol) in dichloromethane (48 mL) was added triethylamine (6.64 mL, 48 mmol) dropwise under ice-bath cooling keeping the temperature below 5° C. The reaction mixture was then stirred at 5° C. for 15 min, and then the ice-bath was removed and stirring was continued for 30 min (resulting in an increase in temperature to 32° C. Then the mixture was re-cooled under ice-bath cooling for another 30 min and then the ice-bath was removed again and allowed to warm up to room temperature and left overnight. The resulting mixture was then poured into HCl (1 N) and ice-water and then extracted with ethyl acetate. The organic extract was then dried over sodium sulphate and evaporated to leave a yellow oil. Purification by chromatography (SiO2, heptane:ethyl acetate=100:0 to 50:50) afforded the title compound (6.35 g, 71%) which was obtained as a light yellow solid. MS: m/e (EI)=187.1 [M].

1. temperaturecooling
2. customthe temperature below 5° C
3. customthe ice-bath was removed
4. stirringstirring
5. waitwas continued for 30 min
6. custom(resulting in
7. temperaturean increase in temperature to 32° C
8. temperatureThen the mixture was re-cooled under ice-bath
9. temperaturecooling for another 30 min
10. customthe ice-bath was removed again
11. temperatureto warm up to room temperature
12. waitleft overnight
13. additionThe resulting mixture was then poured into HCl (1 N) and ice-water
14. extractionextracted with ethyl acetate
15. extractionThe organic extract
16. dry with materialwas then dried over sodium sulphate
17. customevaporated
18. customto leave a yellow oil
19. customPurification by chromatography (SiO2, heptane:ethyl acetate=100:0 to 50:50)

ORD record

ord-9aa2790a3ca3492eba6bbfb64ace437a

Source dataset

uspto-grants-2008_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07414061B2