Thiazine (or oxazine) derivatives and preparation thereof

A method for the prophylaxis or treatment of ischemic encephalopathia in a warm-blooded animal which comprises administering to said warm-blooded animal a pharmaceutically effective amount of a compound of the formula:

• ##STR190## wherein R.sup.1, R.sup.2, R.sup.4 and R.sup.5 are each a hydrogen atom;
• R.sup.3 is a hydrogen atom or a halogen atom;
• X is a sulfur atom;
• R.sup.6 is naphthyl, a sulfur containing monoheterocyclic group or a substituted phenyl group;
• Z.sup.1 denotes two hydrogen atoms;
• Z.sup.2 is an oxygen atom;
• A is a lower alkylene;
• R.sup.7 and R.sup.8 are the same or different and are each a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group or a lower alkyl group that is substituted by a substituted phenyl group, or R.sup.7 and R.sup.8 together with the adjacent nitrogen atom form a nitrogen-containing monoheterocyclic group;
• or a pharmaceutically acceptable salt thereof;
• except for the compound of Formula (I), wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each a hydrogen atom, X is a sulfur atom, R.sup.6 is a halogenophenyl group, Z.sup.1 denotes two hydrogen atoms, Z.sup.2 is an oxygen atom, A is a lower alkylene group, and R.sup.7 and R.sup.8 are the same or different and are each a lower alkyl group.