(1,3)OXAZINO(4,3-A)ISOQUINOLINE DERIVATIVE

The invention relates to new [1,3]oxazino[4,3-a]-isoquinoline derivatives of the formula (I) (I) wherein R1 and R2 represent hydroxyl or alkoxy having from 1 to 6 carbon atoms, R3 is hydrogen, alkyl having from 1 to 8 carbon atoms, cycloakyl or cycloalkenyl having from 3 to 6 carbon atoms, optionally substituted phenyl, aralkyl having from 1 to 4 carbon atoms in the alkyl moiety or heteroaryl, R4 is hydrogen or alkyl having from 1 to 4 carbon atoms, or R3 and R4 together form a -(CH2)n- group, in which n is an integer from 3 to 7, R5 is hydroxyl, halogen or an group, in which R6 is optionally substituted phenyl, X is oxygen or sulfur, and salts thereof. According to another aspect of the invention there is provided a process for the preparation of these compounds. Compounds of formula (I) are pharmaceutically active. Pharmaceutical compositions containing them are also within the scope of the invention.