反应详情

温度

90 °C

A mixture of 1,2-dihydro-4-(3,4-methylenedioxyphenyl)-2-oxo-3-quinoline carboxylic acid obtained in reference example 1 (10 g, 32.3 mmol) and phosphorous oxychloride (100 ml, 1.07 mol) was refluxed with heat for 4 hours. The reaction mixture was distilled to dryness and washed with n-hexane several times. To the residue obtained was added 50 g of polyphosphoric acid, and the mixture was heated at 90° C. for 2 hours. The reaction mixture was poured into ice water to filtrate a crystal precipitated. The crystal obtained was dissolved in tetrahydrofuran to filter off undissolved substances, and purified by silica gel column chromatography (eluent: chloroform) to give 6.0 g (yield 59.9%) of the title compound.

1. temperaturewas refluxed
2. temperaturewith heat for 4 hours
3. distillationThe reaction mixture was distilled to dryness
4. washwashed with n-hexane several times
5. customTo the residue obtained
6. customprecipitated
7. customThe crystal obtained
8. filtrationto filter off undissolved substances
9. custompurified by silica gel column chromatography (eluent: chloroform)