Phosphorus oxychloride → 4-Chloro-7,8-dimethoxybenzo[g]quinoline-3-carbonitrile

HRID 989289Notes

Reaction equation

[CH3:1][O:2][C:3]1[C:4]([O:20][CH3:21])=[CH:5][C:6]2[CH:15]=[C:14]3[C:9]([C:10](=O)[C:11]([C:16]#[N:17])=[CH:12][NH:13]3)=[CH:8][C:7]=2[CH:19]=1.P(Cl)(Cl)([Cl:24])=O>CN(C=O)C>[Cl:24][C:10]1[C:9]2[C:14](=[CH:15][C:6]3[CH:5]=[C:4]([O:20][CH3:21])[C:3]([O:2][CH3:1])=[CH:19][C:7]=3[CH:8]=2)[N:13]=[CH:12][C:11]=1[C:16]#[N:17]

Participants

Conditions

Temperature: 105 °C

Procedure

A mixture of 356.2 mg (1.3 mmol) of 7,8-dimethoxy-4-oxo-1,4-dihydrobenzo[g]quinoline-3-carbonitrile in 5 mL of phosphorus oxychloride and 4 drops of DMF is heated at 100-110° C. for 4.5 hours. After cooling, the mixture is concentrated to dryness in vacuo to give a dark residue. The residue is partitioned between methylene chloride and ice-cooled saturated aqueous sodium carbonate solution. The organic layer is washed with cooled brine and dried over sodium sulfate. The organic solvent is passed through a short column of silica gel, and the column is first eluted with additional methylene chloride, then a 99:1 methylene chloride/ethyl acetate soltion. Removal of the solvent yields 187.0 mg (49.4%) of the product as a bright yellow solid, mp>265° C.

Workup

temperatureAfter cooling
concentrationthe mixture is concentrated to dryness in vacuo
customto give a dark residue
customThe residue is partitioned between methylene chloride and ice-
temperaturecooled saturated aqueous sodium carbonate solution
washThe organic layer is washed with cooled brine
dry with materialdried over sodium sulfate
washthe column is first eluted with additional methylene chloride
customRemoval of the solvent

Sources & evidence

ORD record: ord-a7cf7a1f223a47c18c13dccddd3ef854
Source dataset: uspto-grants-2003_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06638929B2

Reaction notes

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