A process for preparing a compound of general formula which comprise either: a) reacting a compound of general formula with an alcohol of the general formula R6-OH, or a salt thereof, i) in the presence of between 0.05 and 40 mol % of one or more tertiary-amine catalyst(s); and ii) using water as reaction medium and wherein the reaction medium contains less than 10 w/w% of organic solvent; or b) reacting a compound of general formula with a compound of general formula or a salt thereof, i) in the presence of between 0.05 and 40 mol % of one or more tertiary-amine catalyst(s); and ii) using water as reaction medium and wherein the reaction medium contains less than 10 w/w% of organic solvent; wherein: LG represents a leaving group; R1, R2, R3 and R4 represent, independently of one another, hydrogen, halogen, cyano, nitro, alkylcarbonyl, formyl, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, or optionally halogen-substituted alkyl, aryl, alkoxy, alkylthio, alkylsulphinyl or alkylsulphonyl; R5 is hydrogen, halogen, cyano, nitro, alkylcarbonyl, formyl, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, or optionally halogen-substituted alkyl, aryl, alkoxy, alkylthio, alkylsulphinyl or alkylsulponyl, or one of the following radicals: wherein * denotes the point of attachment to the phenyl radical of formula; R6 is substituted or unsubstituted aryl, or substituted or unsubstituted heterocyclyl, or a salt thereof; R7 is hydrogen, fluorine, chlorine or bromine; with the proviso that R6 and the radical: are different from each other. a) reacting a compound of general formula with an alcohol of the general formula R6-OH, or a salt thereof, i) in the presence of between 0.05 and 40 mol % of one or more tertiary-amine catalyst(s); and ii) using water as reaction medium and wherein the reaction medium contains less than 10 w/w% of organic solvent; or i) in the presence of between 0.05 and 40 mol % of one or more tertiary-amine catalyst(s); and ii) using water as reaction medium and wherein the reaction medium contains less than 10 w/w% of organic solvent; b) reacting a compound of general formula with a compound of general formula or a salt thereof, i) in the presence of between 0.05 and 40 mol % of one or more tertiary-amine catalyst(s); and ii) using water as reaction medium and wherein the reaction medium contains less than 10 w/w% of organic solvent; wherein: LG represents a leaving group; R1, R2, R3 and R4 represent, independently of one another, hydrogen, halogen, cyano, nitro, alkylcarbonyl, formyl, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, or optionally halogen-substituted alkyl, aryl, alkoxy, alkylthio, alkylsulphinyl or alkylsulphonyl; R5 is hydrogen, halogen, cyano, nitro, alkylcarbonyl, formyl, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, or optionally halogen-substituted alkyl, aryl, alkoxy, alkylthio, alkylsulphinyl or alkylsulponyl, or one of the following radicals: wherein * denotes the point of attachment to the phenyl radical of formula; R6 is substituted or unsubstituted aryl, or substituted or unsubstituted heterocyclyl, or a salt thereof; R7 is hydrogen, fluorine, chlorine or bromine; with the proviso that R6 and the radical: are different from each other. i) in the presence of between 0.05 and 40 mol % of one or more tertiary-amine catalyst(s); and ii) using water as reaction medium and wherein the reaction medium contains less than 10 w/w% of organic solvent; LG represents a leaving group; R1, R2, R3 and R4 represent, independently of one another, hydrogen, halogen, cyano, nitro, alkylcarbonyl, formyl, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, or optionally halogen-substituted alkyl, aryl, alkoxy, alkylthio, alkylsulphinyl or alkylsulphonyl; R5 is hydrogen, halogen, cyano, nitro, alkylcarbonyl, formyl, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, or optionally halogen-substituted alkyl, aryl, alkoxy, alkylthio, alkylsulphinyl or alkylsulponyl, or one of the following radicals: wherein * denotes the point of attachment to the phenyl radical of formula; R6 is substituted or unsubstituted aryl, or substituted or unsubstituted heterocyclyl, or a salt thereof; R7 is hydrogen, fluorine, chlorine or bromine;