compounds corresponding to the general formula ## str1 ## in which n = 2 or 3 , x = h , f , cl or och 3 , r = h or ch 3 , r 1 = h or ch 3 , r 2 = alkyl , hydroxyalkyl , alkyl , dimethoxyalkyl , 2 - ethyl , 2 - ethyl , 2 - ethyl , aminocarbonylmethyl which is optionally substituted by nitrogen , phenylethyl which is optionally substituted , pyrimidinylaminoalkyl or arylcaronylaminoalkyl , or else r 1 and r 2 form , with the nitrogen which carries them , a piperidine , morpholine , thiomorpholine or piperazine ring , optionally substituted by nitrogen . use in therapeutics .