(R)-2,5-Dihydro-3,6-dimethoxy-2-isopropylpyrazine → 1,4-Bis((2R,5S)-2,5-dihydro-3,6-dimethoxy-2-isopropyl-5-pyrazinyl)-but-2-yne

HRID 976016

反応式

HRID 976016 の反応式
[CH3:1][O:2][C:3]1[C@@H:4]([CH:11]([CH3:13])[CH3:12])[N:5]=[C:6]([O:9][CH3:10])[CH2:7][N:8]=1.[Li][CH2:15][CH2:16][CH2:17][CH3:18].[CH3:19][O:20][C:21]1[CH:22]([CH:29]([CH3:31])[CH3:30])[N:23]=[C:24]([O:27][CH3:28])[CH2:25][N:26]=1>C1COCC1>[CH3:1][O:2][C:3]1[C@@H:4]([CH:11]([CH3:13])[CH3:12])[N:5]=[C:6]([O:9][CH3:10])[C@H:7]([CH2:18][C:17]#[C:16][CH2:15][C@H:25]2[C:24]([O:27][CH3:28])=[N:23][C@H:22]([CH:29]([CH3:31])[CH3:30])[C:21]([O:20][CH3:19])=[N:26]2)[N:8]=1

参加物

5

反応物 3

HCID 736066(R)-2,5-Dihydro-3,6-dimethoxy-2-isopropylpyrazineHCID 38009092,5-Dihydro-2-isopropyl-3,6-dimethoxypyrazineHCID 178418339Butyllithium

生成物 1

HCID 114528411,4-Bis((2R,5S)-2,5-dihydro-3,6-dimethoxy-2-isopropyl-5-pyrazinyl)-but-2-yne収率 77%

試薬・触媒・溶媒 1

HCID 8028Tetrahydrofuran溶媒

反応条件

温度
-78 °C

実験手順

(2R)-(-)-2,5-Dihydro-3,6-dimethoxy-2-isopropylpyrazine 2.76 g (15mmol) was dissolved in 100 ml dry THF and cooled to -78° C., then 9.5 ml of a 1.6M solution BuLi (15 mmol) was added dropwise with stirring. After 1 hour 0.92 g (7.5 mmol) of 1,4-dichloro-2,3-butyne was introduced slowly. TLC and gas chromatography (GC) of the reaction mixture 1 hour later showed substantial amounts of unreacted 2,5-dihydro-3,6-dimethoxy-2-isopropylpyrazine and the monoalkylated product. The reaction was allowed to continue overnight and reach ambient temperature gradually. THF was evaporated off under reduced pressure and the residue partitioned between ether and water. The water phase was extracted twice with ether, dried (MgSO4) and evaporated. Kugelrohr distillation of the reaction mixture to give 2.3g (77%) pure product.

後処理

  1. customreach ambient temperature
  2. customTHF was evaporated off under reduced pressure
  3. customthe residue partitioned between ether and water
  4. extractionThe water phase was extracted twice with ether
  5. dry with materialdried (MgSO4)
  6. customevaporated
  7. distillationKugelrohr distillation of the reaction mixture

出典と根拠

ORDレコード
ord-06cb4186efa54d49b3169c4ce264d158
出典データセット
uspto-grants-1997_03
特許番号
US05610141

関連ノート

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