반응 #42466

반응 방정식

ethyl 4-butyl-8-iodo-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate

oxazole

n-butyllithium

→

title compound

수율 71.7%

Methyl 4-butyl-8-(1,3-oxazol-2-yl)-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate

수율 71.7%

용매

THF

ethyl acetate

tetrahydrofuran

반응 조건

후처리

1. 1
   온도The mixture was warmed to 0° C. for 1 h
2. 2
   온도The mixture was heated
3. 3
   온도at reflux for 3 h
4. 4
   세척washed with water
5. 5
   건조The organic solution was dried (sodium sulfate)
6. 6
   농축concentrated under reduced pressure
7. 7
   기타Purification by silica gel plug (1:1 acetate/hexanes)

실험 절차

To a −70° C. solution of oxazole (227 mg) in tetrahydrofuran (10 mL) was added n-butyllithium (2.5 M in hexanes, 2 mL). After stirred at −70° C. for 30 min, zinc chloride (1 M in ethyl ether, 13 mL) was added. The mixture was warmed to 0° C. for 1 h. To this mixture was then added ethyl 4-butyl-8-iodo-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate (600 mg, 1.6 mmol) in THF (5 mL) followed by tetrakis triphenylphosphine palladium(0) (115 mg). The mixture was heated at reflux for 3 h, diluted with ethyl acetate (300 mL) and washed with water followed by brine. The organic solution was dried (sodium sulfate) and concentrated under reduced pressure. Purification by silica gel plug (1:1 acetate/hexanes) provided 363 mg of the title compound: 1H NMR (300 MHz, CDCl3) δ 7.96, 7.73, 7.40, 7.28, 4.44, 3.90, 3.43, 3.34, 1.61, 1.41, 0.98.

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