2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → HCID 1397657, compound
Reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([C:9]2[CH2:21][CH:12]3[C:13]4[CH:14]=[CH:15][CH:16]=[CH:17][C:18]=4[C:19](=[O:20])[N:11]3[N:10]=2)=[CH:5][CH:4]=1.ClC1C(=O)C(C#N)=C(C#N)C(=O)C=1Cl>C1C=CC=CC=1>[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]([C:9]2[CH:21]=[C:12]3[C:13]4[CH:14]=[CH:15][CH:16]=[CH:17][C:18]=4[C:19](=[O:20])[N:11]3[N:10]=2)=[CH:7][CH:8]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A mixture of 62.00 g 2-(4-methoxyphenyl)-3,3a-dihydro-8H-pyrazolo[5,1-a]isoindol-8-one, 1100 ml of benzene, and 27.2 g. of 2,3-dichloro-5,6-dicyanobenzoquinone was heated under reflux for 2 hours under nitrogen atmosphere. A further 27.2 g of 2,3-dichloro-5,6-dicyanobenzoquinone was added, and the heating was continued for a total of 8 hours. After cooling to 25°, the solid residue was filtered off, and the filtrate was evaporated to dryness under vacuum. The combined solids from the filter and evaporation flask were stirred mechanically for 1 hour with a mixture of 20 g of 85% potassium hydroxide and 1500 g of water. The mixture was filtered, the yellow solid was washed successively with 2 × 500-ml of 5% sodium bicarbonate, 2 × 500-ml of water, and air-dried. The yellow residue was recrystallized from 3000 ml of acetone to yield 55 g (80%) of 2-(4-methoxyphenyl)pyrazolo[ 5,1-a]isoindol-8-one, mp 180-181°.
Workup
- temperatureunder reflux for 2 hours under nitrogen atmosphere
- customwas continued for a total of 8 hours
- temperatureAfter cooling to 25°
- filtrationthe solid residue was filtered off
- customthe filtrate was evaporated to dryness under vacuum
- filtrationThe combined solids from the filter
- customevaporation flask
- filtrationThe mixture was filtered
- washthe yellow solid was washed successively with 2 × 500-ml of 5% sodium bicarbonate, 2 × 500-ml of water
- customair-dried
- customThe yellow residue was recrystallized from 3000 ml of acetone
Sources & evidence
- ORD record
- ord-66944cd641c5433ab9f7b6c7db9b88b2
- Source dataset
- uspto-grants-1976_04
- Patent number
- US03948937
Reaction notes
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