Potassium Carbonate → 2-(4-aminophenyl)-1,2-dihydro-3H-pyrazolo[4,3-c]cinnolin-3-one
Reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([N:10]2[C:22](=[O:23])[C:13]3[N:14]=[N:15][C:16]4[CH:17]=[CH:18][CH:19]=[CH:20][C:21]=4[C:12]=3[NH:11]2)=[CH:6][CH:5]=1)([O-])=O.[Cl-].[NH4+].C(=O)([O-])[O-].[K+].[K+]>C(O)C.O.[Fe]>[NH2:1][C:4]1[CH:5]=[CH:6][C:7]([N:10]2[C:22](=[O:23])[C:13]3[N:14]=[N:15][C:16]4[CH:17]=[CH:18][CH:19]=[CH:20][C:21]=4[C:12]=3[NH:11]2)=[CH:8][CH:9]=1Participants
7
Reactant 3
Product 1
Reagents, catalysts & solvents 3
Conditions
- Temperature
- 80 °C
Procedure
2-(4-nitrophenyl)-1,2-dihydro-3H-pyrazolo[4,3-c]cinnolin-3-one (11.4 g, 37.2 mmol) was suspended in a mixture of ethanol (100 ml) and water (100 ml). Iron powder (11.1 g, 200 mmol) and ammonium chloride (5.34 g, 100 mmol) were added. The mixture was heated to 80° C. overnight, cooled to room temperature and basified with potassium carbonate to pH 9-10. The solids were removed by filtration through a pad of Celite®. The filtrate was extracted with n-butanol (2×200 ml). The combined organic phases were concentrated under vacuum to give a dark red solid. The solid was triturated with methanol (100 ml), filtered and dried under vacuum. The title compound was isolated as a dark red powder (5.58 g, 20.1 mmol, 57%). LCMS: m/z 278 [M+H]+.
Workup
- temperaturecooled to room temperature
- customThe solids were removed by filtration through a pad of Celite®
- extractionThe filtrate was extracted with n-butanol (2×200 ml)
- concentrationThe combined organic phases were concentrated under vacuum
- customto give a dark red solid
- customThe solid was triturated with methanol (100 ml)
- filtrationfiltered
- customdried under vacuum
Sources & evidence
- ORD record
- ord-c2853acc980747d0a0784d37f7d47e71
- Source dataset
- uspto-grants-2012_11
- Patent number
- US08309552B2
Reaction notes
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