Dimethylformamide → 1h-Pyrazolo[4,3-b]pyridine-5,6-dicarboxylic acid,1-methyl-,5,6-dimethyl ester

HRID 864291

反応式

HRID 864291 の反応式
CN(C)[CH:3]=[O:4].P(Cl)(Cl)(Cl)=[O:7].[CH3:11][N:12]1[CH:16]=[C:15]([NH:17][C:18]([CH2:28]C)=[C:19]([C:24](OC)=O)[C:20]([O:22][CH3:23])=[O:21])[CH:14]=[N:13]1.C[N+](C)=CCl.[Cl-]>ClC(Cl)C>[CH3:11][N:12]1[C:16]2[C:15](=[N:17][C:18]([C:28]([O:4][CH3:3])=[O:7])=[C:19]([C:20]([O:22][CH3:23])=[O:21])[CH:24]=2)[CH:14]=[N:13]1

参加物

6

反応物 4

HCID 6228DimethylformamideHCID 24813Phosphorus oxychlorideHCID 77311Chloro-N,N-dimethylformiminium chlorideHCID 19417344Dimethyl [(1-methylpyrazol-4-yl)amino]butenedicarboxylate

生成物 1

HCID 199582161h-Pyrazolo[4,3-b]pyridine-5,6-dicarboxylic acid,1-methyl-,5,6-dimethyl ester収率 71.4%

試薬・触媒・溶媒 1

HCID 63651,1-Dichloroethane溶媒2 回

反応条件

温度
-5 °C

実験手順

Dimethylformamide (7.4 mL, 0.096 mol) is dissolved in 125 mL dichloroethane and the mixture cooled to -5° C. in an acetone/ice bath. Phosphorous oxychloride (8.9 mL, 0.095 mol) is added-in one portion and the clear colorless solution is allowed to warm slowly to room temperature, gradually turning yellow. The unpurified dimethyl [(1-methylpyrazol-4-yl)amino]butenedicarboxylate is dissolved in 75 mL of dichloroethane and added to the chilled Vilsmeier reagent dropwise keeping the reaction temperature below 5° C. The mixture is allowed to warm slowly to room temperature over four hours, and then is heated to reflux for one hour. The mixture is concentrated to a solid which is chromatographed using 3:1 hexanes/ethyl acetate. The fractions containing the desired product are combined and concentrated to give the product as a white solid (16.93 g, 71.4%), melting point 148°-149° C.

後処理

  1. temperatureto warm slowly to room temperature
  2. customthe reaction temperature below 5° C
  3. temperatureto warm slowly to room temperature over four hours
  4. temperatureis heated
  5. temperatureto reflux for one hour
  6. concentrationThe mixture is concentrated to a solid which
  7. customis chromatographed
  8. additionThe fractions containing the desired product
  9. concentrationconcentrated

出典と根拠

ORDレコード
ord-bda6a53387054af0b077e1d026b3e958
出典データセット
uspto-grants-1996_10
特許番号
US05563113

関連ノート

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