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 reacting a compound of formula (II), either with a chlorination or bromination agent or with a compound of formula (III) CI-SO
2
R
9
, R
9
being C
1
-C
4
alkyl, C
1
-C
4
haloalkyl, phenyl or C
1
-C
4
alkyl-substituted phenyl, to form the compound of formula (IV), reacting the compound of formula (IV) with a compound of formula (V) M
+
—O
−
—C(O)—Y wherein Y is as defined above and M
+
is the hydrogen cation or an alkali metal ion, alkaline earth metal ion or ammonium ion, to form the compound of formula (VI) and treating that compound with a cyanide source in the presence of a base.
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 reacting a compound of formula (II), with a bromine or chlorine source to form a compound of formula (III), wherein X is chlorine or bromine; reacting that compound with water to form the compound of formula (IV), converting that compound, using a compound of formula (V), wherein M
+
is the hydrogen cation or an alkali metal ion, alkaline earth metal ion or ammonium ion, into the compound of formula (VI), and treating that compound with a cyanide source in the presence of a base.