摘要：

A process for the preparation of compounds of the general formula (2), wherein R<1> represents the radicals -OR<2> or -NR<3>R<4>; and R<2>, R<3>, R<4>, R<5>, R<6> and R<7> represents radicals separately selected from hydrogen and alkyl, or the acid addition salts thereof, comprising: a) the reaction of a 3,5-dihydroxybenzoic acid of general formula (3) with a compound of the general formula (4): NHR<3>R<4>, wherein R<3>, R<4>, R<5>, R<6> and R<7> are as hereinbefore defined, to produce a compound of general formula (2b), wherein R<3>, R<4>, R<5>, R<6> and R<7> are as hereinbefore defined; and, when preparing compounds of general formula (2) wherein R<1> represents the radical -OR<2>, further comprising: b) hydrolysis of the compound of general formula (2b) to produce a carboxylic acid of general formula (2c), wherein R<3>, R<4>, R<5>, R<6> and R<7> are as hereinbefore defined; and c) esterification of the acid of general formula (2c) to produce an ester of general formula (2d), wherein R<2> represents alkyl and R<3>, R<4>, R<5>, R<6> and R<7> are as hereinbefore defined; or, when preparing compounds of general formula (2) wherein R<1> represents the radical -OR<2> and R<2> represents alkyl, comprising: d) esterification of the amide of general formula (2b) in an acidic medium to produce an ester of general formula (2d).

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