(R)-2,5-Dihydro-3,6-dimethoxy-2-isopropylpyrazine → (2S,5R)-2-(((1r*,3R*,4R*)-3-(tert-butyldimethylsilyloxy)-4-fluorocyclopentyl)methyl)-5-isopropyl-3,6-dimethoxy-2,5-dihydropyrazine

HRID 451805

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HRID 451805 반응식
[CH:1]([C@@H:4]1[C:9]([O:10][CH3:11])=[N:8][CH2:7][C:6]([O:12][CH3:13])=[N:5]1)([CH3:3])[CH3:2].[Li]CCCC.[C:19]([Si:23]([O:26][C@@H:27]1[CH2:31][C@@H:30]([CH2:32]I)[CH2:29][C@H:28]1[F:34])([CH3:25])[CH3:24])([CH3:22])([CH3:21])[CH3:20]>C1COCC1>[Si:23]([O:26][C@H:27]1[C@H:28]([F:34])[CH2:29][C@H:30]([CH2:32][C@H:7]2[C:6]([O:12][CH3:13])=[N:5][C@H:4]([CH:1]([CH3:3])[CH3:2])[C:9]([O:10][CH3:11])=[N:8]2)[CH2:31]1)([C:19]([CH3:22])([CH3:21])[CH3:20])([CH3:25])[CH3:24]

참가 물질

5

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온도
-78 °C

실험 절차

A solution of (R)-2-isopropyl-3,6-dimethoxy-2,5-dihydropyrazine (1.2 g, 1.5 equiv.) in dry THF (30 mL) was cooled to −78° C. n-BuLi (1.6 M in Hexane, 4.08 mL, 1.5 equiv.) was added dropwise. After stirring 1 h at −78° C., a solution of (±)-tert-butyl((1r,2R,4R)-2-fluoro-4-(iodomethyl)cyclopentyloxy)dimethylsilane (1.56 g, 4.36 mmol) in dry THF (8 mL) was added dropwise. The mixture was stirred another 2 h at −78° C. The mixture was warmed up to rt slowly, quenched by sat. NH4Cl solution (30 mL), extracted by diethyl ether (2×150 mL). The combined organic layers were washed by brine (30 mL), dried over Na2SO4. After filtration and concentration, the residue was purified by ISCO (40 g column, 0˜25% EtOAc in Hexanes) to afford (2S,5R)-2-(((1r*,3R*,4R*)-3-(tert-butyldimethylsilyloxy)-4-fluorocyclopentyl)methyl)-5-isopropyl-3,6-dimethoxy-2,5-dihydropyrazine (1.81 g, quant. yield) as a clear oil. MS ESI +ve m/z 415 (M+1).

후처리

  1. additionwas added dropwise
  2. stirringThe mixture was stirred another 2 h at −78° C
  3. temperatureThe mixture was warmed up to rt slowly
  4. customquenched by sat. NH4Cl solution (30 mL)
  5. extractionextracted by diethyl ether (2×150 mL)
  6. washThe combined organic layers were washed by brine (30 mL)
  7. dry with materialdried over Na2SO4
  8. filtrationAfter filtration and concentration
  9. customthe residue was purified by ISCO (40 g column, 0˜25% EtOAc in Hexanes)

출처 및 근거

ORD 기록
ord-aad48de85c9b43afa4e0ddf68c77e349
출처 데이터셋
uspto-grants-2013_07
특허 번호
US08487108B2

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