Intermediates for the preparation of 2-imidazoline-5-ones

A process for preparing a compound having the formula (VI):

• wherein:
• R1 is a C1-C3 alkyl or phenyl radical;
• R2 is a phenyl or pyridyl radical, said radical being optionally substituted with 1 to 3 substituents selected from the group consisting of a halogen atom, a nitro or cyano group and a C1-C3 alkyl or C1-C3 alkoxy radical;
• R4 is a hydrogen atom or an acyl radical;
• and
• R5 is a phenyl, naphthyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, thienyl, benzothienyl, furyl, benzofuryl, quinolyl, isoquinolyl or methylenedioxyphenyl radical, said radical being optionally substituted with 1 to 7 groups, which are the same or different, selected from the meanings of R51;
• R51 is:
• a halogen atom;
• an alkyl, haloalkyl, alkoxy, haloalkoxy, alkylthio, haloalkylthio or alkylsulphonyl radical, which is linear or branched and has 1 to 6 carbon atoms;
• a cycloalkyl, halocycloalkyl, alkenyloxy, alkynyloxy, alkenylthio or alkynylthio radical having 3 to 6 carbon atoms;
• a nitro or cyano group;
• or
• an amino radical which is optionally mono- or disubstituted with an alkyl or acyl radical having 1 to 6 carbon atoms or an alkoxycarbonyl radical of 2 to 6 carbon atoms;
• said process comprising reacting a compound having formula (I) with a compound having formula (V) below in a solvent and at a temperature of between 20° C. and 100° C., according to the scheme: