| abstract |
A compound of formula (I) and pharmaceutically acceptable salts, solvates and hydrolysable esters thereof wherein; X1 represents O or S; R1 and R2 independently represent H, halogen, -CH3 and -OCH3;n represents 1 or 2; X2 represents NH, NCH3 or O; One of Y and Z is N, and the other is O or S; R3 represents phenyl or pyridyl (wherein the N is in position 2 or 3) and is optionally substituted by one or more halogen, NO2, NH2, CF3, OCF3, OC1-6 straight or branched alkyl, C1-6 straight or branched alkyl, alkenyl or alkynyl with the provision that when R3 is pyridyl, the N is unsubstituted; R4 represents CF3 or CH3. |