1,1'-Thiocarbonyldiimidazole → 5,6-dihydro-1-oxo-5-thioxo-1H-pyrazolo[1,2-a][1,2,4]benzotriazine-2-carboxylic acid, ethyl ester

HRID 443494Notes

Reaction equation

HRID 443494 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[N:8]1[C:12]([OH:13])=[C:11]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[CH:10]=[N:9]1.[C:19](N1C=CN=C1)(N1C=CN=C1)=[S:20]>O1CCCC1>[O:13]=[C:12]1[N:8]2[C:3]3[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=3[NH:1][C:19](=[S:20])[N:9]2[CH:10]=[C:11]1[C:14]([O:16][CH2:17][CH3:18])=[O:15]

Participants

4

Reactant 2

HCID 802641,1'-ThiocarbonyldiimidazoleHCID 178469977HCID 178469977, compound

Product 1

HCID 867376775,6-dihydro-1-oxo-5-thioxo-1H-pyrazolo[1,2-a][1,2,4]benzotriazine-2-carboxylic acid, ethyl esterYield 84.8%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

2.47 g 1-(2-aminophenyl)-5-hydroxy-1H-pyrazole-4-carboxylic acid, ethyl ester and 1.78 g 1,1'-thiocarbonyl-bis-[1H-imidazole] are dissolved in 50 ml tetrahydrofuran and heated for 8 hours. The residue, after distilling off the solvent, is recrystallized from dimethylformamide to yield 2.45 g of 5,6-dihydro-1-oxo-5-thioxo-1H-pyrazolo[1,2-a][1,2,4]benzotriazine-2-carboxylic acid, ethyl ester having a melting point of 277°-282° C.; yellow needles.

Workup

  1. temperatureheated for 8 hours
  2. distillationThe residue, after distilling off the solvent
  3. customis recrystallized from dimethylformamide

Sources & evidence

ORD record
ord-5c957c509485427eb0299a1c5be3a516
Source dataset
uspto-grants-1981_04
Patent number
US04260751

Reaction notes

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