| abstract |
A compound of the formula:n n wherein R¹ is a hydrogen atom, a lower alkyl group or a halogen atom; R² and R³ are a hydrogen atom, a lower alkyl group or a 5- to 7-membered cyclic group formed together with the adjacent -C=C-; X is an oxygen atom, a sulfur atom or a methylene group; Y is an optionally substituted methylene group, a divalent 3- to 7-membered homo- or heterocyclic group; R⁶ and R⁷ are a hydrogen atom, a lower alkyl group, a cycloalkyl group, an aryl group, or a nitrogen-containing heterocyclic group formed together with the adjacent nitrogen atom; m is an integer of 0 to 4; and n is an integer of 0 to 4, or a salt thereof. Said compound has an excellent anti-PAF activity, antiallergic action, etc., thus is useful as an antiasthmatic agent. |