| abstract |
Thiazine (or oxazine) derivatives of the formula [I]: <CHEM> wherein R<1> and R<2> are both H or form a naphthalene ring together with the benzene ring; R<3> and R<4> are both H, or one of them is halogen and another is H; X is S or O; R<5> and R<6> are each i) H, ii) lower alkyl, iii) cycloalkyl, iv) substituted phenyl, v) naphthyl, vi) lower alkyl which is substituted by substituted or unsubstituted phenyl, or vii) S-containing heterocyclic group; one of Z<1> and Z<2> is O and another is H2; A is lower alkylene; R<7> and R<8> are each i) H, ii) lower alkyl, iii) lower alkenyl, iv) lower alkynyl, or v) lower alkyl which is substituted by substituted or unsubstituted phenyl, or both form together N-containing heterocyclic group; provided that when both of R<1> and R<2> are H, Z<2> is O and either one of R<5> and R<6> is substituted phenyl, naphthyl or S-containing heterocyclic group, or their salts, which have calcium antagonistic activity within the cerebral tissues and are useful for prophylaxis and treatment of ischemic encephalopathia and/or cerebral neurocyte dyscrasia, and process for preparing said compounds. |