Patent ID: 7582589

Claim:
A compound of formula (I) where Het is a 5- or 6-membered heterocyclic ring containing one to three heteroatoms, each independently selected from oxygen, nitrogen and sulphur, the ring being substituted by one to three groups R 4 ; R 1 is hydrogen, optionally substituted (C 1-4 )alkyl, formyl, optionally substituted (C 1-4 )alkylC(═O), optionally substituted (C 1-4 )alkylC(═O)O, optionally substituted (C 1-4 )alkoxy(C 1-4 )alkyl, optionally substituted allyl, optionally substituted propargyl or optionally substituted allenyl; each R 2 is, independently, halogen, optionally substituted (C 1-4 )alkyl, optionally substituted (C 1-4 )alkoxy or optionally substituted (C 1-4 )alkoxy(C 1-4 )alkyl; R 3 is either at position 2 or at position 4 of the thiophene ring and is an organic group containing three to thirteen carbon atoms and at least one silicon atom and, optionally, one to three heteroatoms, each independently selected from oxygen, nitrogen and sulphur, and is optionally substituted by one to four independently selected halogen atoms; each R 4 is, independently, halogen, C 1-3 alkyl, C 1-3 haloalkyl, C 1-3 alkoxy(C 1-3 )alkyl or cyano; r is 0, 1 or 2; and X is O or S; or an N-oxide thereof.