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

HRID 443493Notes

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)=[O: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](=[O:20])[N:9]2[CH:10]=[C:11]1[C:14]([O:16][CH2:17][CH3:18])=[O:15]

Participants

Conditions

Temperature: 90 °C

Procedure

24.7 g 1-(2-aminophenyl)-5-hydroxy-1H-pyrazole-4-carboxylic acid, ethyl ester and 16.2 g 1,1'-carbonyl-bis-[1H-imidazole] are dissolved in 300 ml tetrahydrofuran and stirred for 8 hours at room temperature and one hour at 90° C. The solid residue, after distilling off the solvent, is recrystallized from dimethylformamide to yield 21 g of 5,6-dihydro-1,5-dioxo-1H-pyrazolo[1,2-a][1,2,4]-benzotriazine-2-carboxylic acid, ethyl ester having a melting point of 269°-271° C.; white-yellow crystals.

Workup

distillationThe solid residue, after distilling off the solvent
customis recrystallized from dimethylformamide

Sources & evidence

ORD record: ord-468d3ef0225543418e329201f2e85d68
Source dataset: uspto-grants-1981_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04260751

Reaction notes

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