1-amidooctahydropyrido[2,1-c][1,4]oxazine compounds

A compound selected from 1-acylaminooctahydropyrido[2,1-][1,4]oxazines of formula (I):

• ##STR43## in which:
• R.sub.1 represents hydrogen or an optionally-substituted mono- or bicyclic system chosen form phenyl, naphthyl, pyridyl, thienyl, furyl, quinolyl, isoquinolyl, indolyl, indolinyl, perhydroindolyl, and benzofuryl,
• A represents a .sigma. bond or a saturated or unsaturated, linear or branched alkylene having 1 to 4 carbon atoms inclusive, with the reservation that, when R.sub.1 represents hydrogen, A cannot represent a .sigma. bond,
• R.sub.2 and R.sub.3 each represent, independently of one another:
• hydrogen,
• linear or branched and optionally-substituted alkyl having 1 to 6 carbon atoms inclusive,
• a group --(CH.sub.2).sub.n B, n being 0, 1, 2, or 3 and B representing a C.sub.5 -C.sub.7 cycloalkyl or phenyl monocyclic system, substituted or unsubstituted,
• R.sub.4 and R.sub.5 each represent, independently of one another, hydrogen, linear or branched alkyl having 1 to 4 carbon atoms inclusive or a group --(CH.sub.2).sub.n B as above defined, the term substituted associated with the expression "monocyclic system" means that the system may be substituted with 3 or 4 lower-alkoxy having 1 to 4 carbon atoms inclusive branched or linear or 2 lower-alkoxy plus 2 halogen atoms SO.sub.2 R.sub.6, the substituents being identical or different,
• wherein the term associated with the expression alkyl means that this group may be substituted wit one or more linear or branched lower-alkoxy having 1 to 4 carbon atoms inclusive,
• its isomers, diastereoisomers and enantiomers, isolated or in the form of a mixture, and
• its addition salts with a pharmaceutically-acceptable inorganic or organic acid.