A process for the preparation of a 2-substituted-5-(1-alkylthio)alkyl-pyridine N-oxide according to formula, wherein L represents a single bond, or R 1, S and L taken together form a 5- membered ring and the compound of formula has the following structure: R 1 represents (C 1 -C 4) alkyl; R 2 and R 3 individually represent hydrogen, methyl, ethyl, fluoro, chloro or bromo; n is an integer from 0-3; and Y represents (C 1 -C 4) haloalkyl; in which: i) an enamine according to formula wherein R 1, R 2, R 3, L, and n are as previously defined, and R 4 and R 5 independently represent C 1 -C 8 alkyl, C 2 -C 8 alkenyl, C 1 -C 8 arylalkyl, C 1 -C 8 haloalkyl, C 1 -C 8 alkoxyalkyl, C 1 -C 8 alkylaminoalkyl, aryl or heteroaryl or R 4 and R 5 taken together with N represent a 5- or 6-membered saturated or unsaturated ring is condensed with an α, β-unsaturated ketone according to formula wherein Y is as previously defined; and X 1 represents halogen, OR 6, OSO 2 R 6, SR 6, SOR 6, SO 2 R 6 or NR 7 R 8, where R 6 represents hydrogen, C 1 -C 8 alkyl, C 2 -C 8 alkenyl, C 1 -C 8 arylalkyl, C 1 -C 8 haloalkyl, C 1 -C 8 alkoxyalkyl, C 1 -C 8 alkylaminoalkyl, aryl or heteroaryl, and R 7 and R 8 independently represent hydrogen, C 1 -C 8 alkyl, C 2 -C 8 alkenyl, C 1 -C 8 arylalkyl, C 1 -C 8 haloalkyl, C 1 -C 8 alkoxyalkyl, C 1 -C 8 alkylaminoalkyl, aryl or heteroaryl or R 7 and R 8 taken together with N represent a 5- or 6-membered saturated or unsaturated ring; to provide an intermediate compound according to formula wherein R 1, R 2, R 3, R 4, R 5, L and n are as previously defined; and ii) the intermediate compound according to formula is cyclized using an amine nucleophile according to formula or an acid salt thereof H 2 N-X 2, wherein X 2 represents hydroxyl. L represents a single bond, or R 1, S and L taken together form a 5- membered ring and the compound of formula has the following structure: R 1 represents (C 1 -C 4) alkyl; R 2 and R 3 individually represent hydrogen, methyl, ethyl, fluoro, chloro or bromo; n is an integer from 0-3; and Y represents (C 1 -C 4) haloalkyl; i) an enamine according to formula wherein R 1, R 2, R 3, L, and n are as previously defined, and R 4 and R 5 independently represent C 1 -C 8 alkyl, C 2 -C 8 alkenyl, C 1 -C 8 arylalkyl, C 1 -C 8 haloalkyl, C 1 -C 8 alkoxyalkyl, C 1 -C 8 alkylaminoalkyl, aryl or heteroaryl or R 4 and R 5 taken together with N represent a 5- or 6-membered saturated or unsaturated ring is condensed with an α, β-unsaturated ketone according to formula wherein Y is as previously defined; and X 1 represents halogen, OR 6, OSO 2 R 6, SR 6, SOR 6, SO 2 R 6 or NR 7 R 8, where R 6 represents hydrogen, C 1 -C 8 alkyl, C 2 -C 8 alkenyl, C 1 -C 8 arylalkyl, C 1 -C 8 haloalkyl, C 1 -C 8 alkoxyalkyl, C 1 -C 8 alkylaminoalkyl, aryl or heteroaryl, and R 7 and R 8 independently represent hydrogen, C 1 -C 8 alkyl, C 2 -C 8 alkenyl, C 1 -C 8 arylalkyl, C 1 -C 8 haloalkyl, C 1 -C 8 alkoxyalkyl, C 1 -C 8 alkylaminoalkyl, aryl or heteroaryl or R 7 and R 8 taken together with N represent a 5- or 6-membered saturated or unsaturated ring; to provide an intermediate compound according to formula wherein R 1, R 2, R 3, R 4, R 5, L and n are as previously defined; and R 1, R 2, R 3, L, and n are as previously defined, and R 4 and R 5 independently represent C 1 -C 8 alkyl, C 2 -C 8 alkenyl, C 1 -C 8 arylalkyl, C 1 -C 8 haloalkyl, C 1 -C 8 alkoxyalkyl, C 1 -C 8 alkylaminoalkyl, aryl or heteroaryl or R 4 and R 5 taken together with N represent a 5- or 6-membered saturated or unsaturated ring is condensed with an α, β-unsaturated ketone according to formula wherein Y is as previously defined; and X 1 represents halogen, OR 6, OSO 2 R 6, SR 6, SOR 6, SO 2 R 6 or NR 7 R 8, where R 6 represents hydrogen, C 1 -C 8 alkyl, C 2 -C 8 alkenyl, C 1 -C 8 arylalkyl, C 1 -C 8 haloalkyl, C 1 -C 8 alkoxyalkyl, C 1 -C 8 alkylaminoalkyl, aryl or heteroaryl, and R 7 and R 8 independently represent hydrogen, C 1 -C 8 alkyl, C 2 -C 8 alkenyl, C 1 -C 8 arylalkyl, C 1 -C 8 haloalkyl, C 1 -C 8 alkoxyalkyl, C 1 -C 8 alkylaminoalkyl, aryl or heteroaryl or R 7 and R 8 taken together with N represent a 5- or 6-membered saturated or unsaturated ring; Y is as previously defined; and X 1 represents halogen, OR 6, OSO 2 R 6, SR 6, SOR 6, SO 2 R 6 or NR 7 R 8, where R 6 represents hydrogen, C 1 -C 8 alkyl, C 2 -C 8 alkenyl, C 1 -C 8 arylalkyl, C 1 -C 8 haloalkyl, C 1 -C 8 alkoxyalkyl, C 1 -C 8 alkylaminoalkyl, aryl or heteroaryl, and R 7 and R 8 independently represent hydrogen, C 1 -C 8 alkyl, C 2 -C 8 alkenyl, C 1 -C 8 arylalkyl, C 1 -C 8 haloalkyl, C 1 -C 8 alkoxyalkyl, C 1 -C 8 alkylaminoalkyl, aryl or heteroaryl or R 7 and R 8 taken together with N represent a 5- or 6-membered saturated or unsaturated ring; ii) the intermediate compound according to formula is cyclized using an amine nucleophile according to formula or an acid salt thereof H 2 N-X 2, wherein X 2 represents hydroxyl.