Novel compounds of formula (I): wherein R
1
, R
2
, R
3
, R
4
, m, R
5
, R
6
, n and Y are as defined in claim
1
; or N-oxides, salts and optical isomers thereof. Furthermore, the present invention relates to processes for preparing compounds of formula (I), to herbicidal compositions comprising them and to methods of using them to control plants or to inhibit plant growth.
Compounds of formula I: wherein R
1
, R
2
, R
3
, R
4
, m, R
5
, R
6
, n and Y are as defined in claim
1
; or N-oxides, salts and optical isomers thereof. Furthermore, the present invention relates to processes for preparing compounds of formula (I), to herbicidal compositions comprising them and to methods of using them to control plants or to inhibit plant growth.