A compound of formula I, ** Formula ** wherein R1 is C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C7 cycloalkyl, C4-C10 cycloalkenyl, aryl, (R2) 2C>； = C- , halogen, hydroxy, C1-C6 alkoxy, (C1-C6) -S alkyl, cycloalkenyl (C4-C10) oxy, cycloalkenyl (C4-C10) -S-, aryloxy, aryl-S-, heteroaryloxy, heteroaryl-S- , (R3) 2N-, (R4) 2C>； = N-, heterocyclyl, heteroaryl, C1-C6 arylalkyl, (1-amino-1-carboxymethyl) -C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 hydroxyalkyl, (C1-C6) alkoxy C1-C6 alkyl, (C1-C6) alkyl -S-C1-C6 alkyl, (R3) 2N-C1-C6 alkyl, C1-C6 heterocyclylalkyl, C2-C6 carboxyalkenyl, cycloalkyl (C3-C7) ) C2-C6 alkenyl, C2-C6 arylalkyl, (C1-C6 alkoxy) C2-C6 alkenyl, C2-C6 heterocyclyl alkenyl, C2-C6 heteroarylalkyl, C2-C6 cycloalkynyl, C2-C6 alkynyl, C2-C6 alkynyl, C2-C6 alkynyl -C6, (C1-C6) alkoxy C2-C6 alkynyl, C2-C6 heterocyclylalkyl, C2-C6 heteroarylalkyl, C1-C6 haloalkoxy, C1-C6 hydroxyalkoxy, C1-C6 alkoxy, C1-C6 alkoxy ) - (C>； = O) -O-, R5 - (S>； = O) -, R5- (O>； = S>； = O) -, hydroxyalkoxy (C1-C6) C1-C6 alkyl, (C1-C6 alkoxy) - (C>； = O) -C2 alkenyl C6 or (C1-C6) alkyl - (C>； = O) -O-C1-C6 alkyl, wherein said C4-C10 cycloalkenyl, aryl, heterocyclyl, heteroaryl or C3-C7 cycloalkyl as such or as part of another group are unsubstituted or substituted with 1, 2 or 3 R6 substituents； R2 is, independently in each case, carboxy or aryl, wherein said aryls are, independently in each case, unsubstituted or substituted with 1, 2 or 3 R6 substituents； R3 is, independently in each case, H, C1-C6 alkyl, C3-C7 cycloalkyl, aryl, cycloalkyl (C3-C7) C1-C6 alkyl, hydroxyalkyl C1-C6 or alkoxy (C1-C6) C1-C6 alkyl, in wherein said C3-C7 cycloalkyl or aryl as such or as part of other groups are, independently in each case, unsubstituted or substituted with 1 substituent which is C1-C6 alkyl, halogen, hydroxy, (C1-C6) alkoxy or C1- hydroxyalkyl C6； R4 is, independently in each case, H or aryl, wherein said aryls are, independently in each case, unsubstituted or substituted w
