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

HRID 54174

反応式

HRID 54174 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-a77062d5646d4f869936606dd576b9d1
出典データセット
uspto-grants-1997_04
特許番号
US05622913

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