Diethyl Ether → 1-Benzyl 2-(tert-butyl) 4-hydroxypyrazolidine-1,2-dicarboxylate

HRID 1061620ノート

反応式

HRID 1061620 の反応式
[C:1]([O:5][C:6]([N:8]1[CH2:12][C:11](=[O:13])[CH2:10][N:9]1[C:14]([O:16][CH2:17][C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1)=[O:15])=[O:7])([CH3:4])([CH3:3])[CH3:2].CCOCC>O1CCCC1>[C:1]([O:5][C:6]([N:8]1[CH2:12][CH:11]([OH:13])[CH2:10][N:9]1[C:14]([O:16][CH2:17][C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1)=[O:15])=[O:7])([CH3:4])([CH3:2])[CH3:3]

参加物

4

反応物 2

HCID 3283Diethyl EtherHCID 207247551-Benzyl 2-tert-butyl 4-oxopyrazolidine-1,2-dicarboxylate

生成物 1

HCID 207247531-Benzyl 2-(tert-butyl) 4-hydroxypyrazolidine-1,2-dicarboxylate収率 93%

試薬・触媒・溶媒 1

HCID 8028Tetrahydrofuran溶媒

反応条件

温度
-78 °C

実験手順

4-Oxo-pyrazolidine-1,2-dicarboxylic acid 1-benzyl ester 2-tert-butyl ester, 27, (5.0 g, 15.6 mmol) is dissolved in tetrahydrofuran (150 mL) and the solution cooled to −78° C. A 5.0 M solution of borane-dimethyl sulfide complex in ether (6.24 mL, 31.2 mmol) is added dropwise via syringe. After 40 minutes at −78° C., the reaction is quenched by slow addition of a saturated aqueous solution of ammonium chloride (20 mL). The cooling bath is removed, and the mixture allowed to warm to ambient temperature with vigorous stirring. The solvent is removed in vacuo and the residue diluted with dichloromethane (200 mL). The mixture is washed with water (150 mL) and saturated aqueous sodium bicarbonate solution (150 mL), water and brine. The combined aqueous layers are extracted with dichloromethane (200 mL), water (150 mL), NaCl (sat.) (200 mL), dried over sodium sulfate, filtered and concentrated in vacuo to afford 4.66 g (93% yield) of the desired product as a clear, viscous oil.

後処理

  1. customthe reaction is quenched by slow addition of a saturated aqueous solution of ammonium chloride (20 mL)
  2. customThe cooling bath is removed
  3. temperatureto warm to ambient temperature with vigorous stirring
  4. customThe solvent is removed in vacuo
  5. additionthe residue diluted with dichloromethane (200 mL)
  6. washThe mixture is washed with water (150 mL) and saturated aqueous sodium bicarbonate solution (150 mL), water and brine
  7. extractionThe combined aqueous layers are extracted with dichloromethane (200 mL), water (150 mL), NaCl (sat.) (200 mL)
  8. dry with materialdried over sodium sulfate
  9. filtrationfiltered
  10. concentrationconcentrated in vacuo

出典と根拠

ORDレコード
ord-27bacd2340f8497995124335cfe2aced
出典データセット
uspto-grants-2005_11
特許番号
US06960593B2

反応ノート

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