Derivatives of 4,4-difluorobut-3-enylsulfinic acid and their use as pesticides

A compound of formula (I):

• CF2═CX—CH2—CH2—S(O)—R (I)
• wherein X represents hydrogen, halogen or lower alkyl, and R represents a group OR1 or NR2R3 wherein R1, R2 and R3 are each independently selected from hydrogen and alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, alkaryl, heteroaryl and heteroaryalkyl groups, or R2 and R3 together with the adjacent nitrogen atom represent a nitrogen containing heterocyclic group which may contain a further heteroatom selected from oxygen, sulfur and nitrogen, and wherein any of the groups represented by R1, R2 and R3 may optionally be substituted by one or more substituents selected from halogen, cyano, nitro, hydroxy, hydrocarbyloxy, amino, hydrocarbylamino, dihydrocarbylamino, carboxy, hydrocarbyloxycarbonyl, carboxamido, hydrocarbylaminocarbonyl, dihydrocarbylaminocarbonyl, hydrocarbylthio, hydrocarbylsulfinyl, and hydrocarbylsulfonyl, wherein any such hydrocarbyl groups may optionally be substituted by one or more substituents as aforesaid;
• and salts, esters and amides thereof.