Dimethylformamide → 2-phenethyl-2H-pyrazole-3-carbaldehyde

HRID 1363316ノート

反応式

HRID 1363316 の反応式
[CH2:1]([N:9]1[CH:13]=[CH:12][CH:11]=[N:10]1)[CH2:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1.[Li]CCCC.CN([CH:22]=[O:23])C>C1COCC1>[CH2:1]([N:9]1[C:13]([CH:22]=[O:23])=[CH:12][CH:11]=[N:10]1)[CH2:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1

参加物

5

反応物 3

HCID 6228DimethylformamideHCID 1112673758416-69-6HCID 178418339Butyllithium

生成物 1

HCID 469418572-phenethyl-2H-pyrazole-3-carbaldehyde収率 43%

試薬・触媒・溶媒 1

HCID 8028Tetrahydrofuran溶媒

反応条件

温度
-78 °C

実験手順

To a stirred, pre-cooled solution of 1-phenethyl-1H-pyrazole (1.10 g, 6.39 mmol) in THF (30 mL) at −78° C., was added dropwise n-BuLi (4.8 mL, 7.66 mmol; 1.6 M in hexane) at such a rate that the internal temperature stayed below −70° C. The mixture was stirred at −78° C. for 1.5 h, during which time the anion precipitated out as a yellow solid. Then DMF (1.25 mL, 15.97 mmol) was added neat and dropwise, and the reaction stirred at −78° C. for 90 min when TLC indicated the reaction was not progressing any further. It was quenched with NH4Cl solution (10 mL), allowed to warm to rt and extracted with EtOAc (4×50 mL). The combined organic extracts were washed with water, brine, dried (Na2SO4), filtered and concentrated. Purification by flash chromatography (Isco CombiFlash) 0-10% EtOAc/heptane provided 2-phenethyl-2H-pyrazole-3-carbaldehyde (540 mg, 43%). 1H NMR (400 MHz, CDCl3) δ ppm 3.09-3.15 (m, 2H), 4.74-4.80 (m, 2H), 6.88 (d, J=2.10 Hz, 1H), 7.16-7.20 (m, 2H), 7.20-7.32 (m, 3H), 7.58 (d, J=2.01 Hz, 1H), 9.77 (s, 1H); LCMS-MS (ESI+) 200.88 (M+H).

後処理

  1. customstayed below −70° C
  2. customprecipitated out as a yellow solid
  3. stirringdropwise, and the reaction stirred at −78° C. for 90 min when TLC
  4. customIt was quenched with NH4Cl solution (10 mL)
  5. temperatureto warm to rt
  6. extractionextracted with EtOAc (4×50 mL)
  7. washThe combined organic extracts were washed with water, brine
  8. dry with materialdried (Na2SO4)
  9. filtrationfiltered
  10. concentrationconcentrated
  11. customPurification by flash chromatography (Isco CombiFlash) 0-10% EtOAc/heptane

出典と根拠

ORDレコード
ord-95995a252a3248fdb93516b1b853e98a
出典データセット
uspto-grants-2011_02
特許番号
US07884124B2

反応ノート

読み込み中…