Method for producing 2,4-dihydroxyquinoline derivatives
AssigneeMitsubishi Kasei Corporation
InventorsNaoshi Imaki, Yuki Takuma, Mari Oishi
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Abstract
A method for producing a 2,4-dihydroxyquinoline derivative of the formula: ##STR1## wherein each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is a hydrogen atom, a lower alkyl group, a lower alkoxy group or a halogen atom, and its tautomer, which comprises cyclizing an aryl malonic acid amide ester derivative of the formula: ##STR2## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as defined above, and R.sup.5 is a lower alkyl group, by means of polyphosphoric acid.
Claims4
A method for producing a 2,4-dihydroxyquinoline compound of the formula:
- wherein each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is a hydrogen atom, a lower alkyl group, a lower alkoxy group or a halogen atom, and its tautomer, which comprises cyclizing an aryl malonic acid amide ester compound of the formula:
- ##STR9## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as defined above, and R.sup.5 is a lower alkyl group, by means of polyphosphoric acid at a temperature of from 50.degree. C. to 200.degree. C., wherein said polyphosphoric acid is prepared in a molar ratio of P.sub.2 O.sub.5 /H.sub.3 PO.sub.4 within a range of from 0.4 to 0.6.
The method of claim 4, wherein said polyphosphoric acid is present in an amount of from 0.1 to 50 ml relative to 1.0 g of said aryl malonic acid amide ester compound.
Dependencies are inferred from the claim text.