Phosphorus oxychloride → 5-Chloro-1,3-dimethyl-1H-dipyrazolo[1,5-a:4',3'-e]pyrazine-6-carboxylic acid, ethyl ester

HRID 1678850Notes

Reaction equation

HRID 1678850 reaction equation
O[C:2]1[C:3]2[N:4]([N:13]=[CH:14][C:15]=2[C:16]([O:18][CH2:19][CH3:20])=[O:17])[C:5]2[N:10]([CH3:11])[N:9]=[C:8]([CH3:12])[C:6]=2[N:7]=1.P(Cl)(Cl)([Cl:23])=O>CN(C)C=O>[Cl:23][C:2]1[C:3]2[N:4]([N:13]=[CH:14][C:15]=2[C:16]([O:18][CH2:19][CH3:20])=[O:17])[C:5]2[N:10]([CH3:11])[N:9]=[C:8]([CH3:12])[C:6]=2[N:7]=1

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178469946HCID 178469946, compound

Product 1

HCID 539664075-Chloro-1,3-dimethyl-1H-dipyrazolo[1,5-a:4',3'-e]pyrazine-6-carboxylic acid, ethyl ester

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

92.5 gms. of 5-hydroxy-1,3-dimethyl-1H-dipyrazolo[1,5-a:4',3'-e]pyrazine-6-carboxylic acid, ethyl ester, together with 300 ml. of phosphorus oxychloride and 3 ml. of dimethylformamide are refluxed for 5 hours. After distilling off the phosphorus oxychloride, the reaction mixture is poured onto ice and the crude 5-chloro-1,3-dimethyl-1H-dipyrazolo[1,5-a:4',3'-e]pyrazine-6-carboxylic acid ethyl ester, is filtered under suction, then recrystallized from acetone, yield 83 gms. of white crystals, m.p. 130°-132°.

Workup

  1. distillationAfter distilling off the phosphorus oxychloride
  2. additionthe reaction mixture is poured onto ice
  3. filtrationthe crude 5-chloro-1,3-dimethyl-1H-dipyrazolo[1,5-a:4',3'-e]pyrazine-6-carboxylic acid ethyl ester, is filtered under suction
  4. customrecrystallized from acetone, yield 83 gms

Sources & evidence

ORD record
ord-ddc3671ae4d14625baf2bd98fd082c41
Source dataset
uspto-grants-1978_03
Patent number
US04077956

Reaction notes

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