5-HYDROXY COUMARANE DERIVATIVES, THEIR PREPARATION AND USE

of the disclosure A compound of the formula (I) wherein R is a lower alkyl group, R0 is hydrogen or an acyl group, R1 and R2 are lower alkyl groups which may optionally be substituted or wherein R1 and R2 are combined to form a butadienylene group which may optionally be substituted, R3 and R4 are hydrogen or alkyl groups which may optionally be substituted or wherein R3 and R4 are combined to form a polymethylene group, and R5 is a lower alkyl, aromatic or heterocyclic group which may optionally be substituted or a pharmaceutically acceptable salt thereof, exerts cardiovascular system improving action and antiallergic action and can be used as pharmaceutics, e.g. antithromotics, antiallergic agents etc.