| abstract |
A compound of formula (I) and pharmaceutically acceptable salts,solvates and hydrolysable esters thereof Formula I:(I); wherein X1 represents O or S; R<1> and R<2> are independently H or C1-3 alkyl or R<1> and R<2> which are bonded to the same carbon atom may together with the carbon atom to which they are bonded form a 3-5 membered cycloalkyl ring; R<3> and R<4> independently represent H, Halogen, -CH3 and OCH3_; R<5> represents H or C1-6 alkyl X2 represents NH, NCH3 or O; One of Y and Z is N, and the other is O or S; R<6> represents phenyl or pyridyl (wherein the N is in position 2 or 3) and is optionally substituted by one or more halogen, CF3, C1-6 straight or branched alkyl (optionally substituted by halogen), with the provision that when R<6> is pyridyl, the N is unsubstituted. |