Synthesis of some new spirocyclic β-lactam and spirocyclic thiazolidin-4-one derivatives

Selective oxidation of 4-amino-2-methyl-5,10-dioxo-1,5,10,10a-tetrahydrobenzo[g]-quinoline-3-carbonitrile (1) with selenium dioxide provided, 4-amino-2-formyl-5,10-dioxo-1,5,10,10a-tetrahydrobenzo[g]quinoline-3-carbonitrile (2). The one-pot reaction of compound 2 with ethyl cyanoacetate and thiourea in ethanol yielded 4-amino-2-(5-cyano-6-oxo-2-thioxo-1,2,3,6-tetrahydropyrimidin-4-yl)-5,10-dioxo-1,5,10,10a-tetrahydrobenzo[g]-quinoline-3-carbonitrile (3). The cycloaddition reaction of chloroacetic acid with compound 3 yielded 7-(4-amino-3-cyano-5,10-dioxo-1,5,10,10a-tetrahydrobenzo-[g]quinolin-2-yl)-3,5-dioxo-3,5-dihydro-2H-thiazolo[3,2-a]pyrimidine-6-carbonitrile (4). Moreover, Ehrlich-Sachs condensation reaction of compound 4 with the aromatic nitroso compounds 5a-c gave the corresponding new Schiff bases 6a-c. Staudinger's ketene-imine cycloaddition reaction of compounds 6a-c with chloroacetyl chloride afforded the corresponding spiro[chloroazetidinethiazolopyrimidine] derivatives, 7a-c. On the otherhand, cycoladdition reaction of thioglycolic acid with Schiff bases 6a-c yielded the corresponding spiro[thiazolidinethiazolopyrimidine] derivatives, 8a-c. Structures of the new compounds were elucidated by compatible analytical and spectroscopic (IR, 1H NMR and MS) measurements. Moreover, the reaction mechanisms that account for formation of the synthesized compounds have been discussed

Synthesis and Antimicrobial Evaluation of Novel Pyrazole, Imidazole and Pyrimidine Derivatives Possessing Imidazo[4,5-b]indol Moiety

In this study, novel pyrazole, imidazole, pyrimidine derivatives bearing imidazo[4,5-b]indol moiety were successfully synthesized and their chemical structures were identified and confirmed by different spectral techniques. All the synthesized compounds were tested against four bacterial strains (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) and two fungi (Aspergillus flavus and Candida albicans). The obtained results show that the synthesized compounds could find fruitful applications as antibacterial and antifungal agents in pharmaceutical chemistry

Novel Β-lactams and Thiazolidinone Derivatives from 1,4-dihydroquinoxaline Schiff’s Base: Synthesis, Antimicrobial Activity and Molecular Docking Studies

A series of novel isolated β-lactams 3a-c and thiazolidinone derivatives 4a-c were successfully synthesized from reactions of new Schiff's bases 2a-c with chloroacetyl chloride and thioglycolic acid. The chemical structures of the new compounds were confirmed through different spectroscopic techniques including IR, 1H NMR, 13C NMR, mass spectrometry and elemental analysis. The antimicrobial activity of the obtained compounds was assessed in-vitro against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria and Aspergillus flavus and Candida albicans fungi. Furthermore, a molecular docking study was carried out and the results indicated that compounds 3b and 4b displayed comparable binding affinity scores as that of glutamate. These two compounds are promising candidates as antibacterial and antifungal agents that would deserve further investigations

Characteristic Strength and Treatability of a Recycled Paper Mill Wastewater in a UASB Reactor

The characteristic strength of wastewater from a recycled paper mill in Nairobi, Kenya and its suitability for treatment in a UASB (upflow anaerobic sludge blanket) reactor at ambient temperature were assessed. TheBOD5/COD relationship showedthat the wastewater is of high strength, biodegradable and has a potential to increase in strength with time. The effluent is acidic and deficient in basic inorganic nutrients such as nitrogen and phosphorus which are required for biological treatment. The effluent has less sulphate and total solids as compared to wastewater from paper mills using virgin wood pulp and is thus suitable for treatment by anaerobic process. In a UASB reactor, about 63 per cent COD removal and total biogas production rate of 0.2 l/g COD were attained at a load of 12 to 15 KgCOD/m3/day. A well-pelletized sludge was formed in the reactor over a period of 4 months. (Journal of Civil Engineering, JKUAT: 2002 8: 61-78