Microwave-assisted synthesis and characterization of novel symmetrical substituted 19-membered tetrathiadiaza metal-free and metallophthalocyanines and investigation of their biological activities

► The synthesis of 4,14-bis[(4-methylphenyl)sulfonyl]-3,4,5,6,9,10,13,14,15,16-dekahydro-2H,8H,12H-1,17,7,11,4,14-benzotetrathiadiazacyclononadecin-19,20-dicarbonitrile (3) was obtained by base-catalyzed macrocyclization reaction of N,N′-(2,2′-(propane-1,3-diylbis(sulfanediyl))bis(ethane-2,1 diyl))bis(4-methylbenzene sulfonamide) (1) with the 1, 2-bis(2-iodomercaptoethyl)-4,5-dicyanobenzene (2). ► Of all tested, four samples exhibited antimicrobial activity against test microorganisms, among which, B. catarrhalis was the most sensitive one with a MIC value around 0.312 mg/mL followed by a yeast, C. albicans (MIC. 0.625 mg/mL). ► The thermal behaviors of the metal-free phthalocyanine (4) and metallophthalocyanines (5-9) were investigated by TG/DTA and it was seen that our novel compounds were not stable above 202 °C.