| abstract |
The present invention relates to compounds of formula I, or a pharmaceutically acceptable salt of such a compound, wherein A 1 , R 1 , R a , R b , R c and R d are as defined herein. The present invention further relates to a herbicidal composition comprising a compound of formula I, to an intermediate compound used in the preparation of a compound of formula I, to a process for the preparation of a compound of formula I and to a process for producing a compound of formula I < / RTI > (I) |