Benzyl 3-oxopiperazine-1-carboxylate → 5-Ethoxy-3,6-dihydro-2H-pyrazine-1-carboxylic acid benzyl ester

HRID 394537

反応式

HRID 394537 の反応式
[CH2:1]([O:8][C:9]([N:11]1[CH2:16][CH2:15][NH:14][C:13](=[O:17])[CH2:12]1)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.F[B-](F)(F)F.[CH2:23]([O+](CC)CC)[CH3:24]>ClCCl>[CH2:1]([O:8][C:9]([N:11]1[CH2:12][C:13]([O:17][CH2:23][CH3:24])=[N:14][CH2:15][CH2:16]1)=[O:10])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

参加物

4

反応物 2

HCID 736777Benzyl 3-oxopiperazine-1-carboxylateHCID 2723982Triethyloxonium tetrafluoroborate

生成物 1

HCID 542316815-Ethoxy-3,6-dihydro-2H-pyrazine-1-carboxylic acid benzyl ester収率 95%

試薬・触媒・溶媒 1

HCID 6344Dichloromethane溶媒

実験手順

To a solution of 3-oxo-piperazine-1-carboxylic acid benzyl ester (2.0 g, 8.54 mmol, Maybridge) in dichloromethane (18 mL) at room temperature was added triethyloxonium tetrafluoroborate (4.1 g, 21.3 mmol). This mixture was allowed to stir for about 3 days then quenched by the addition of ice chips followed by saturated aqueous sodium bicarbonate until a neutral pH was obtained. The organic layer was separated and the aqueous layer was extracted with chloroform (3×). The combined organic extracts were washed with brine (1×), dried over sodium sulfate, and concentrated to give 2.11 g (95%) of the title compound of Example 259, Step A as a slightly yellow oil that was sufficiently pure to carry on to the next step. 1H NMR (CDCl3, 300 MHz) δ 7.43-6.97 (c, 5H), 5.17 (s, 2H), 4.10 (q, 2H), 3.98 (s, 2H), 3.60-3.40 (c, 4H), 1.27 (t, 3H); MS (APCI) 263 (MH+).

後処理

  1. customthen quenched by the addition of ice chips
  2. customwas obtained
  3. customThe organic layer was separated
  4. extractionthe aqueous layer was extracted with chloroform (3×)
  5. washThe combined organic extracts were washed with brine (1×)
  6. dry with materialdried over sodium sulfate
  7. concentrationconcentrated

出典と根拠

ORDレコード
ord-d884e7109bdd44abae4c2de4bab70bf8
出典データセット
uspto-grants-2003_08
特許番号
US06602875B2

関連ノート

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