Rhone-Poulenc Sante

Rhone-Poulenc Industries

Rhone-Poulenc Agrochimie

Philagro

Daniel Michelet

Dominique Petre

Michel Rakoutz

Michel Baudouin

Gerard Soula

Serge Veracini

Karel Formanek

Process for the preparation of a 4-hydroxyquinoline of the formula: ##STR1## in which R represents a hydrogen atom or one, two or three substituents, which may be the same or different, selected from halogen atoms, alkyl radicals containing 1 to 4 carbon atoms, alkoxy radicals containing 1 to 4 carbon atoms, and the trifluoromethyl radical, the substituent(s) being in the 2-, 3-, 5-, 6-, 7- or 8-position, which comprises oxidizing a 1,2,3,4-tetrahydroquinolin-4-one of the general formula: ##STR2## in which R is as hereinbefore defined, in a basic medium, under pressure, by means of excess oxygen or air at a temperature between 80.degree. and 150.degree. C. The 4-hydroxyquinoline products are useful for the preparation of therapeutically useful substances.

Process for the preparation of 4-hydroxyquinolines

Optionally aldehyde substituted polyphenols are prepared by oxidizing, with hydrogen peroxide, a hydroxybenzaldehyde bearing at least one aldehyde substituent ortho- and/or para- to the nuclear hydroxyl group, in an aqueous reaction medium and in the presence of an alkali or alkaline earth metal base, the process being characterized in that the pH of the reaction medium is continuously maintained at a value no greater than 7 throughout the course of the oxidation reaction. The subject process is well suited for the preparation of, e.g., hydroxy-p-vanillin from guaiacol, and the novel compound 2,4,6-triformylphenol.

Preparation of polyphenols by oxidation of hydroxybenzaldehydes

4-Amino-chloroquinolines of the formula: ##STR1## in which R.sub.1 represents a hydrogen atom or an alkyl radical (1 to 5 carbon atoms), and R.sub.2 represents an alkyl radical (1 to 5 carbon atoms) optionally substituted by a dialkylamino group, or a phenyl radical optionally substituted by one or more carboxy and hydroxy radicals and alkyl radicals (1 to 4 carbon atoms) optionally substituted by a dialkylamino group, are prepared by the condensation of an amine of the formula: ##STR2## with a chloro-1,2,3,4-tetrahydroquinolin-4-one of the formula: ##STR3## with aromatization of the tetrahydroquinoline, the reaction being carried out in the presence of a ruthenium based catalyst on a support. The 4-amino-chloroquinoline products are useful as pharmaceuticals.

Process for the preparation of 4-amino-chloroquinolines

Process for the preparation of 4-hydroxyquinolines of the general formula: ##STR1## in which R represents a hydrogen atom, or one, two or three substituents, which may be the same or different, selected from halogen atoms, alkyl radicals containing 1 to 4 carbon atoms, alkoxy radicals containing 1 to 4 carbon atoms, and the trifluoromethyl radical, the substituent(s) being in the 2-, 3-, 5-, 6-, 7- or 8-position, by the oxidation, by means of oxygen or air, in the presence of a catalyst based on platinum or ruthenium, or alloys thereof, of a 1,2,3,4-tetrahydroquinolin-4-one of the general formula: ##STR2## in which R is as defined above.

Preparation of 4-hydroxyquinolines

Process for the preparation of 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran from ortho-methallyloxyphenol or ortho-methallylpyrocatechol. It consists in heating ortho-methallyloxyphenol or ortho-methallylpyrocatechol in the presence of an aluminum derivative. 2,3-Dihydro-2,2-dimethyl-7-hydroxybenzofuran can be used for the synthesis of carbofuran, which is a polyvalent insecticide.

Process for the preparation of

Aliphatic/aromatic ethers are prepared by reacting an aliphatic halide with either an alkali or alkaline earth metal, or ammonium phenolate or naphtholate, in an inert organic solvent, and in the presence of at least one tertiary amine sequestering agent having the formula:

Preparation of aliphatic/aromatic ethers

2,3-Dihydro-2,2-dimethyl-7-hydroxybenzofuran is prepared by heating isobutenylpyrocatechol or isobutenylpyrocatechol/methallylpyrocatechol admixtures, at cyclization/isomerization temperatures, in the presence of a catalytic amount of an organic sulfonic acid.

Preparation of 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran

Unsaturated ethers of diphenols are prepared from alkenyl halides and diphenols as reagents and by carrying out the reaction in two zones at different temperatures. Intermediates for perfumes, aromas and insecticides are so prepared.

Process for the preparation of unsaturated ethers

Process for the preparation of 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofurane, a carbofuran intermediate, from methallylpyrocatechol comprises heating the methallylpyrocatechol in the presence of water and optionally also in the presence of an inert organic solvent having a boiling point above 70.degree. C., the volume ratio of solvent to water being less than 3, the weight ratio of water to ortho-methallylpyrocatechol being between 0.3 and 5, and at a temperature of preferably 170.degree.-230.degree. C.

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Daniel Michelet