반응 #47671

반응 방정식

ethyl acetate

(L)-leucine methyl ester hydrochloride

(E)-4-bromo-3-(2-methyl-benzooxazol-4-yloxy)-but-2-enoic acid ethyl ester

N,N-diisopropylethylamine

→

(S)-4-methyl-2-[4-(2-methyl-benzooxazol-4-yloxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-pentanoic acid methyl ester

수율 56.0%

용매

acetonitrile

반응 조건

후처리

1. 1
   온도The reaction mixture was then cooled to room temperature
2. 2
   여과The mixture was then filtered
3. 3
   세척The filtrate was washed successively with aqueous saturated ammonium chloride, water, and brine
4. 4
   건조dried over sodium sulfate
5. 5
   여과filtered
6. 6
   농축concentrated in vacuo
7. 7
   workup.DISSOLUTIONThe residue was dissolved in tetrahydrofuran (5 mL)
8. 8
   기타microwaved in an Emry Optimizer microwave reaction vessel at 160° C., for 3 h
9. 9
   온도The mixture was then cooled
10. 10
    농축concentrated in vacuo
11. 11
    기타the residue was purified by ISCO Combiflash chromatography (40 g Silicycle, 5% to 50% ethyl acetate/hexanes)

실험 절차

A mixture of (L)-leucine methyl ester hydrochloride (0.570 g, 3.14 mmol), (E)-4-bromo-3-(2-methyl-benzooxazol-4-yloxy)-but-2-enoic acid ethyl ester (0.970 g, 2.85 mmol) and N,N-diisopropylethylamine (0.809 g, 6.21 mmol) in acetonitrile (20 mL) in a sealed tube was heated at 100° C. for 5 h. The reaction mixture was then cooled to room temperature and ethyl acetate was added. The mixture was then filtered. The filtrate was washed successively with aqueous saturated ammonium chloride, water, and brine and then dried over sodium sulfate, filtered and concentrated in vacuo. The residue was dissolved in tetrahydrofuran (5 mL) and microwaved in an Emry Optimizer microwave reaction vessel at 160° C., for 3 h. The mixture was then cooled and concentrated in vacuo and the residue was purified by ISCO Combiflash chromatography (40 g Silicycle, 5% to 50% ethyl acetate/hexanes) to afford (S)-4-methyl-2-[4-(2-methyl-benzooxazol-4-yloxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-pentanoic acid methyl ester (0.570 g, 56%) as a brown oil.

출처