| abstract |
The invention relates to the novel materials of formula (I), where R1 is an optionally substituted L-aryl or L-heteroaryl, such that L is: an alkyl or CO, or L'-X, with L' being an alkyl and X being O or S; R2 is H or an alkyl; R3 is an alkyl optionally substituted by Hal; and R4 is Hou Hal, wherein said materials are in any isomeric form and the salts thereof, to be used as drugs. |