| abstract |
The present invention relates to a process for the preparation of compounds of formula (I) wherein the substituents are as defined in claim 1, by reaction of a compound of formula (II) wherein the substituents are as defined in claim 1, either a1) with triphenylphosphine dibromide or triphenylphosphine dichloride or a2) with RSO2CI, wherein R is C1C4alkyl, C1-C4 fluoroalkyl, benzyl, phenyl, nitrophenyl, halophenyl or C1-C6alkylphenyl, in the presence of a base, to form a compound of formula (III) wherein the substituents are as defined in claim 1 ; and conversion of that compound in the presence of a base into a compound of formula I, and also to novel nitrobenzene intermediates for use in that process. |