A method for the preparation of a compound of formula (I) wherein R 1 is selected from CHF 2 and CF 3 , Q is selected from chloro, bromo and fluoro, comprising each of the following steps: reacting a compound of formula (II) wherein R 2 is selected from C 1-6 -alkyl and arylalkyl, and R 21 is COCH 3 ; with a compound of formula (III) wherein " " represents a single bond, a double bond or two single bonds, and when " " represents a double bond or two single bonds, " = = " is a single bond, and when " " represents a single bond, " = = " is a double bond; R 3 represents oxygen when " " represents a double bond and R 3 represents O-C 1-6 -alkyl when " " represents a single bond or two single bonds; in the presence of an acid catalyst to form a compound of formula (IV) wherein R 2 and R 21 is as defined above; reacting the resulting compound of formula (IV) with an aromatic or aliphatic thiol to form a compound of formula (VI) wherein R 21 is defined above; reacting the compound of formula (VI) with aqueous N(Bu) 4 + OH - to form a compound of formula (VII) wherein R 21 is as defined above; alkylating the resulting compound of formula (VII) with a hydrochlorofluorocarbon reagent, R 1 -Cl (VIII) wherein R 1 is as defined above, to form a compound of formula (IX) wherein R 1 and R 21 are as defined above; reacting the compound of formula (IX) with a pyridine compound of formula (X) wherein Q is as defined above and Q X is selected from chloro, bromo, fluoro and iodo to form a compound of formula (XI); wherein R 1 and Q are as defined above; and oxidating the resulting compound of formula (XI) to prepare the compound of formula (I) wherein R 1 and Q are as defined above. reacting a compound of formula (II) wherein R 2 is selected from C 1-6 -alkyl and arylalkyl, and R 21 is COCH 3 ; with a compound of formula (III) wherein " " represents a single bond, a double bond or two single bonds, and when " " represents a double bond or two single bonds, " = = " is a single bond, and when " " represents a single bond, " = = " is a double bond; R 3 represents oxygen when " " represents a double bond and R 3 represents O-C 1-6 -alkyl when " " represents a single bond or two single bonds; in the presence of an acid catalyst to form a compound of formula (IV) wherein R 2 and R 21 is as defined above; reacting the resulting compound of formula (IV) with an aromatic or aliphatic thiol to form a compound of formula (VI) wherein R 21 is defined above; reacting the compound of formula (VI) with aqueous N(Bu) 4 + OH - to form a compound of formula (VII) wherein R 21 is as defined above; alkylating the resulting compound of formula (VII) with a hydrochlorofluorocarbon reagent, R 1 -Cl (VIII) wherein R 1 is as defined above, to form a compound of formula (IX) wherein R 1 and R 21 are as defined above; reacting the compound of formula (IX) with a pyridine compound of formula (X) wherein Q is as defined above and Q X is selected from chloro, bromo, fluoro and iodo to form a compound of formula (XI); wherein R 1 and Q are as defined above; and oxidating the resulting compound of formula (XI) to prepare the compound of formula (I) wherein R 1 and Q are as defined above. <EOS>