A green multicomponent synthesis of bioactive pyrimido[4,5-b]quinoline derivatives as antibacterial agents in water catalyzed by RuCl3·xH2O

One Pot Synthesis, Photophysical and X-ray Studies of Novel Highly Fluorescent Isoquinoline Derivatives with Higher Antibacterial Efficacy Based on the In-vitro and Density Functional Theory

“…3a, 4, 5, 6 and 7a, polarity of solvent has a little effect on the absorption maxima. All the compounds (1-5) are red-shifts with increasing solvent polarity (dye1 shifted 17 nm, dye 2 shifted 12 nm, dye 3 shifted 15 nm, dye 4 shifted 12 and dye 5 sifted 12 nm on going from n-Hexane to DMSO) indicating some polar character of isoquinoline dues (1)(2)(3)(4)(5) in the ground state. These features indicate a strongly allowed π-π* transition with charge transfer characters.…”

“…The reaction seemed to be started by first addition of active hydrogen of 6-methoxy-1,2,3,4-tetrahydro-naphthalin-1-one to the ethylenic double bond of compound i. Ammonia was added to the nitrile group in ii to give iii which looses a molecule of water to give iv, which in turn was converted to the final product by auto-oxidation. The IR spectrum of compounds (1)(2)(3)(4)(5) shows the characteristic band at 3412-3442 cm −1 due to presence -NH 2 group and at 2218-2242 cm −1 attributed to the CN group. IR spectra shows sharp peek at 1234-1245 cm −1 due presence of C=N stretch which is conform to formation of quinoline.…”

“…General Method for the Synthesis of Benzoquinoline Derivatives (1)(2)(3)(4)(5) A one-pot mixture of the appropriate aldehyde (0.011 mol), 6-methoxy-1,2,3,4-tetrahydro-naphthalin-1-one (2 g, 0.011 mol), malononitrile (0.74 g, 0.011 mol) and ammonium acetate (6.78 g, 0.088 mol) in absolute ethanol (25 mL) was refluxed for 6 h [22]. The reaction mixture was allowed to cool, and the resulting precipitate was filtered, washed with water, dried and recrystallized from ethanol and chloroform.…”

“…Stokes shifts (Δν ss ) of compounds (1)(2)(3)(4)(5) in different solvents were calculated, as shown in Tables 6, 7, 8, 9 and 10, using the following the equation [29]:…”

“…Its traces of interest date back to the beginning of the 20th century but the first reports on their medical applications began to appear in the Fifties as antibiotic drugs against tuberculosis and leprosy [3]. Quinoline derivatives are of considerable interest because of their chemistry and potentially beneficial biological activity, such as antibacterial, antifungal, antiviral, antiamoebic, antimalarial and antitumor activity [4][5][6][7]. Quinoline derivatives use as intermediate for the formation of various fused bi-cyclic heterocyclic compounds such as pyrazolo quinoline, thiazolo quinoline, oxazolquinoline [8][9][10].…”