Patent ID: 7709648

Claim:
A process for the preparation of 2-substituted-5-(1-alkylthio)alkylpyridine (I), wherein R 1 and R 2 independently represent H or C 1 -C 4 alkyl; R 3 represents C 1 -C 4 alkyl; and R 4 represents C 1 -C 4 alkyl or C 1 -C 4 haloalkyl; which comprises: a) condensing a substituted enone (II), wherein R 4 as previously defined; and R 5 and R 6 independently represent C 1 -C 4 alkyl; with an enamine (III), wherein R 1 , R 2 and R 3 are as previously defined; and R 7 and R 8 independently represent C 1 -C 4 alkyl or R 7 and R 8 taken together with N represent a 5-membered saturated or unsaturated ring; b) cyclizing the reaction mixture from step a) in the presence of ammonia or a reagent capable of generating ammonia to produce a 2,3,5-substituted pyridine (IV), wherein R 1 , R 2 , R 3 , R 4 and R 6 are as previously defined; and saponifying and decarboxylating the 2,3,5-substituted pyridine (IV) to give 2-substituted-5-(1-alkylthio)alkylpyridine (I).