Diethyl Oxalate → Ethyl 2-(3,5-dichloro-2,6-dimethoxypyridin-4-yl)-2-oxoacetate

HRID 1375408ノート

反応式

HRID 1375408 の反応式
[Cl:1][C:2]1[C:3]([O:11][CH3:12])=[N:4][C:5]([O:9][CH3:10])=[C:6]([Cl:8])[CH:7]=1.[Li+].CC([N-]C(C)C)C.[C:21](OCC)(=[O:27])[C:22]([O:24][CH2:25][CH3:26])=[O:23].[Cl-].[NH4+]>C1COCC1>[Cl:8][C:6]1[C:5]([O:9][CH3:10])=[N:4][C:3]([O:11][CH3:12])=[C:2]([Cl:1])[C:7]=1[C:21](=[O:27])[C:22]([O:24][CH2:25][CH3:26])=[O:23]

参加物

6

反応物 4

HCID 7268Diethyl OxalateHCID 25517Ammonium ChlorideHCID 2724682Lithium diisopropylamideHCID 694735033,5-Dichloro-2,6-dimethoxypyridine

生成物 1

HCID 58786806Ethyl 2-(3,5-dichloro-2,6-dimethoxypyridin-4-yl)-2-oxoacetate収率 78%

試薬・触媒・溶媒 1

HCID 8028Tetrahydrofuran溶媒2 回

反応条件

温度
-78 °C

実験手順

A solution of 5.20 g (25 mmol) of 3,5-dichloro-2,6-dimethoxypyridine (J. Bratt, H. Suschitzky, J.C.S. Perkin I, 1983:1689–1693) in 40 mL THF is added dropwise over 30 minutes to a solution of 20 mL (30 mmol) of 1.5 M LDA in 20 mL THF at −78° C. The resulting solution is stirred at −78° C. for 1 hour, and 4.5 mL (33 mmol) of diethyl oxalate is then added. The temperature is allowed to rise slowly to room temperature and aqueous ammonium chloride solution is added, and the solvent is removed under vacuum. The residue is extracted into EtOAc and chromatographed on SiO2, eluting with hexane-EtOAc (9:1), to give 5.97 g (78%) of the title compound: mp (hexane) 195–196° C.

後処理

  1. customto rise slowly to room temperature
  2. customthe solvent is removed under vacuum
  3. extractionThe residue is extracted into EtOAc
  4. customchromatographed on SiO2
  5. washeluting with hexane-EtOAc (9:1)

出典と根拠

ORDレコード
ord-1c76a0564a4b4b7a929680bd5d8bde0a
出典データセット
uspto-grants-2007_01
特許番号
US07169778B2

反応ノート

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