Synthesis and Characterisation of 1,1 '-{[3,5-Bis(dodecyloxy-carbonyl)-4-(thiophen-3-yl)-1,4-dihydropyridine-2 ,6-diyl]bis(methylene)}bis(pyridin-1-ium) Dibromide

In the present work, construction of double-charged cationic amphiphilic 1,1'-{[3,5-bis(dodecyHoxy-carbonyl)-4-(thiophen-3-yl)-1,4-dihydropyridine-2,6-diyllbis-(methylene)}bis(pyridin-1-ium) dibromide (7) was performed in four steps. Dodecyl 3-oxo-butanoate (1) was condensed with thiophene-3-carbaldehyde (2) which was necessary for Hantzsch cyclisation dodecyl (E/Z)-3-oxo-2-(thiophen-3-ylmethylene)butanoate (3). Two-component Hantzsch type cyclisation of dodecyl (E/Z)-3-aminobut-2-enoate (4) and dodecyl (E/Z)-3-oxo-2-(thiophen-3-ylmethylene)butanoate (3) gave 3,5-bis(dodecyloxycarbonyl)-2,6-dimethyl-4-(thiophen-3-yl)-1,4-dihydropyridine (5). Bromination of compound 5 followed by nucleophilic substitution of bromine with pyridine gave the desired cationic amphiphilic 1,4-dihydropyridine 7. The obtained target compound 7 and new intermediates 3, 5 and 6 were fully characterised by IR, UV, H-1 NMR, C-13 NMR, HRMS or microanalysis. Characterisation of nanoparticles formed by the cationic 1,4-dihydropyridine 7 in an aqueous solution was performed by DLS measurements.