Aminoalkyl benzothiazolinones

A compound selected from those of formula (I):

• ##STR12## in which:
• R.sub.1 represents hydrogen or alkyl or substituted alkyl,
• and R.sub.2 represents a group of formula R.sub.21 :
• ##STR13## in which:
• R.sub.3 and R.sub.4 together form a saturated 5- to 9-membered heterocycle which may contain other hetero atoms chosen from oxygen and sulfur and which may be unsubstituted or substituted or 4-(methoxyphenyl)-piperazin-1-yl,
• or a group of formula R.sub.22 :
• ##STR14## in which n represents 2, 3 or 4,
• and R.sub.5 and R.sub.6, which are identical, represent hydrogen or halogen,
• it being understood that in the formula (I),
• the term "substituted" associated with the heterocycle formed by --NR.sub.3 R.sub.4 means that the substitution may be made by one or more alkyl,
• the terms "alkyl" and "alkoxy" denote linear or branched groups containing 1 to 6 carbon atoms inclusive,
• an optical isomer thereof, and an addition salt thereof with a pharmaceutically-acceptable acid or, when R.sub.1 represents hydrogen, an addition salt thereof with a pharmaceutically-acceptable base.