| abstract |
Novel benzopyran and benzoxazine derivatives represented by the general formula: wherein R1 and R2 represent a lower haloalkyl group, R3 represents a hydrogen atom, etc., R4 represents a heterocyclic group or A-O- wherein A represents a cyclic structure, etc., R5 and R6 represent a lower haloalkyl, X represents =N-, N?O, etc, are disclosed. These compounds exhibit K+ channel opening activating and can be widely used as an anti-asthma drug, an anti-epilepsy drug, etc. |