By reaction of beta-alanine (I) with the phosphorous acid and PCl3 in chlorobenzene at 100 C.
The condensation of 4,6-dichloro-1,3,5-triazin-2-amine (I) with 6-amino-1-methylquinolinium chloride (II) in refluxing ethanol/water gives the target bis quinolinium chloride.