Compounds of formula (I): in which:R1 represents a phenyl group or naphthyl group, optionally substituted by one or more atoms or groups chosen, independently of one another, from: halogen, (C1-C6)alkyl, halo(C1-C6)alkyl, (C1-C6)alkoxy, halo(C1-C6)alkoxy, (C1-C6)thioalkyl, —S(O)(C1-C6)alkyl, —S(O)2(C1-C6)alkyl, hydroxyl, hydroxy(C1-C6)alkylene, CHO, COOH, (C1-C6)alkoxy(C1-C6)alkyleneoxy, NRaRb, CONRaRb, SO2NRaRb, NRcCORd, OC(O)NRaRb, OCO(C1-C6)alkyl, NRcC(O)ORe or NRcSO2Re; X represents from 1 to 4 substituents which are identical to or different from one another and which are chosen from hydrogen, halogen, (C1-C6)alkyl or (C1-C6)alkoxy, it being possible for the (C1-C6)alkyl to be optionally substituted by one or more groups chosen from a halogen, (C1-C6)alkoxy or hydroxyl; R2 and R3 represent, independently of one another, a hydrogen atom, a (C1-C6)alkyl group optionally substituted by an Rf group, or a CHO or COOH group; X and R3 can together form, with the carbon atoms which carry them, a carbocycle of 5 to 7 carbon atoms; R4 represents a hydrogen atom or a (C1-C6)alkyl group; Ra and Rb represent, independently of one another, a hydrogen atom or a (C1-C6)alkyl, aryl(C1-C6)alkylene or aryl group; or Ra and Rb together form, with the nitrogen atom which carries them, an azetidine, pyrrolidine, piperidine, azepine, morpholine, thiomorpholine, piperazine or homopiperazine group, this group being optionally substituted by a (C1-C6)alkyl, aryl or aryl(C1-C6)alkylene group; Rc and Rd represent, independently of one another, a hydrogen atom or a (C1-C6)alkyl, aryl(C1-C6)alkylene or aryl group; or Rc and Rd together form a (C2-C5)alkylene group; Re represents a (C1-C6)alkyl, aryl(C1-C6)alkylene or aryl group; or Rc and Re together form a (C2-C5)alkylene group; Rf represents a hydroxyl, oxo, CHO or COOH group, in the form of the base or of an addition salt with an acid.Therapeutic use and synthetic process.