| abstract |
The present invention relates to novel coumarin derivatives of formula (I) wherein: X= O or S; n= zero, 1, 2, 3 or 4; R5 and R6, which can be the same or different, are optionally unsaturated C1-C4 alkyl groups, or together with t he nitrogen atom they form a residue of cyclic amines optionally containing oth er heteroatoms; R1= CH3 or phenyl; R2 and R4, which can be the same or differen t, are H, OH, allyl, halogen or methyl. |