Method for preparing 5-amino-benzofuran derivatives
AssigneeSanofi
InventorsXavier Bon, Jean-Louis Delepine, Laure Jourdin, Denis Largeau, Philippe Vayron
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Abstract
The invention relates to a method for preparing 5-amino-benzoyl-benzofuran derivatives having the general formula in which R1 is hydrogen or an alkyl or aryl group and R2 is hydrogen, an alkyl, alkoxy or dialkylaminoalkoxy group. According to the invention, the compounds having formula I are prepared by hydrogenating a 5-nitro-benzofuran derivative having the general formula in which R1 and R2 have the same meaning as above in the presence of palladised charcoal as a catalyst and in an ether or a mixture of ether as a solvent, thus forming the desired compounds.
Claims26
A process for the preparation of 5-amino-benzoyl-benzofuran derivatives of general formula:
- in which R1 represents hydrogen or an alkyl or aryl group and R2 represents hydrogen or an alkyl, alkoxy or dialkylaminoalkoxy group, comprising hydrogenating a 5-nitrobenzofuran derivative of general formula:
- in which R1 and R2 have the same meanings as above, in the presence of a palladium-on-charcoal catalyst and in a solvent comprising an ether or a mixture of ethers.
A process for the preparation of sulfonamidobenzofuran derivatives of general formula:
- and of their pharmaceutically acceptable salts, in which R1 represents hydrogen or an alkyl or aryl group, R2 represents hydrogen or an alkyl, alkoxy or dialkylaminoalkoxy group and R3 represents an alkyl or aryl group, comprising:
- a) hydrogenating a 5-nitrobenzofuran derivative of general formula:
- in which R1 and R2 have the same meanings as above, in the presence of a palladium-on-charcoal catalyst and in a solvent comprising an ether or a mixture of ethers to form a reaction medium comprising a 5-amino-benzoyl-benzofuran derivative, in the free base form, of general formula:
- in which R1 and R2 have the same meanings as above,
- b) treating said reaction medium with a halide of general formula:
- Hal-R3 IV
- in which Hal represents a halogen and R3 has the same meaning as above, in the presence of a basic agent, and forming the sulfonamidobenzofuran derivative of general formula III in the free base form, and optionally reacting the formed derivative with an organic or inorganic acid in order to form a pharmaceutically acceptable salt thereof.
A reaction medium, comprising:
- a) a 5-nitrobenzofuran derivative of general formula:
- in which R1 represents hydrogen or an alkyl or aryl group and R2 represents hydrogen or an alkyl, alkoxy or dialkylaminoalkoxy group,
- b) palladium-on-charcoal, and
- c) an ether or a mixture of ethers, as solvent.
Dependencies are inferred from the claim text.