Patent ID: 8318942

Claim:
A process for producing a compound of formula (I), wherein R 1 and R 4 independently represent H, R 2 and R 3 independently represent H, F, an alkyl having from 1 to 4 carbon atoms, or an alkoxy having from 1 to 4 carbon atoms; R 5 represents a phenyl or a substituted phenyl; and n is 0, wherein the process comprises: a) a reaction of 4-pyridinecarboxaldehyde with a compound of formula (II) in refluxing toluene or benzene to form, in the presence of a stoichiometric amount or a greater than a stoichiometric amount of a strong acid selected from an alkyl sulfonic acid, benzene sulfonic acid, or a substituted benzene sulfonic acid, a compound of the formula (III); b) a catalytic hydrogenation of a compound of formula (III) or the compound of formula (V) in a solvent selected from water, an alcohol, an ether, an ester, or an organic acid, at a temperature of between about 0° C. and about 150° C., in the presence of a catalyst selected from platinum, palladium, nickel, ruthenium, or salts or oxides thereof, and at a pressure of between about 1 atmosphere and about 100 atmospheres of H 2 to yield a compound of formula (IV); and c) an N-alkylation reaction of a compound of formula (IV) with a compound of formula Y—(CH 2 ) n+1 R 5 , wherein Y represents a chlorine atom, a bromine atom, or an iodine atom, R 5 represents a phenyl or a substituted phenyl, and n is 0; in the presence of base at a temperature of from about 0° C. to about 150° C. to yield a compound of formula (I); wherein X − is an alkyl sulfonate, benzene sulfonate, or a substituted benzene sulfonate.