Ravi R. Vidule
Oct 1, 2011
Citations
0
Influential Citations
1
Citations
Journal
Indian journal of applied research
Abstract
Synthesis of substituted 4-arylidene-3-methyl-1H-pyrimido[6,1-b]quinazoline-1,10(4H)-diones [4a-t] is attempted by the condensation of aromatic aldehydes [3a-d] with 3-methyl-1H-pyrimido[6,1-b]quinazoline1,10(4H)-diones derivatives [2a-e] in the presence of piperdine. [2a-e] were obtained by azeotropic distillation of 6-methyl uracil and deravaties of 1H-benzo[d][1,3]oxazine-2,4-diones [1a-e]. The structures of synthesized compounds are confirmed by IR and 1HNMR, 13CNMR and mass spectral studies. Further, they were screened in vitro for antibacterial activity against Escherichia coli and Salmonella typhi. Antifungal activity is evaluated against Aspergillus niger and Penicillium chrysogenum using Paper disc diffusion method. Some of the compounds were found to exhibit promising antibacterial and antifungal activities. Introduction The fused heterocyclic those are important because of the wide range of their biological activity which was obtained from heterocyclic structures. Among them different nitrogen heterocycles that have been explored for their biologically important molecules. Fused heterocycles like quinazolinones are of interest as they possess potential bioactive molecules and having wide range of importance in the field of medicinal chemistry because of their biological potential. They are known to exhibiting pharmacological activities such as antitumor [1], In vitro anticancer activity [2] anticonvulsant activity [3], Parkinson’s disease [4], anti-oxidant, anti-inflammatory and analgesic activities [5], antimicrobial activity, potent antiinflammatory and analgesic activities [6], Pharmacological study shows that the these derivatives implement depressive action on the CNS and neuroleptic activity.[7] Hence, the present communication comprises the Synthesis and antimicrobial studies of some new Substituted 4-arylidene-3-methyl-1H-pyrimido[6,1-b]quinazoline-1,10(4H)-diones. MATERIALS AND METHODS All the reagents were of analytical reagent grade and were used without further purification. All the products were synthesized and characterized by their spectral analysis. All chemical and solvents were purchased from S.D. Fine chemicals (India).Melting points were taken in open capillary tube. IR spectra (KBr,ν, cm-1) were recorded on Perkin-Elmer Spectrophotometer and 1H NMR400 MHz (CDCl3)and chemical shifts are given in δ (ppm), 13C NMR 7 MHz (CDCl3). The mass spectra were performed using VG 2AB-3F spectrometer (70 ev), (M+1). All reactions were fowlled by TLC (Silica gel, aluminum sheets 60 F254, Merck). Experimental All the chemical and solvents used were of A.R. grade. All chemicals used were of E-Merck and S.D. fine Ltd. Melting points were determined in an open capillary tube and are uncorrected. The purity of the compound has been checked by TLC. IR spectra were recorded in CHCl3 on a Shimadzu FTIR-8300 spectrophotometer. The 1HNMR(300 MHz) and 13C NMR (70 MHz) were run on a Bruker Avance DPX-250 spectrometer in CDCl3 using tetramethylsilane as an internal standard. Chemical shift values are given in d scale. Mass spectra were recorded on VG 2AB-3F spectrometer (70 ev), (M+1). The in vitro biological screenings of the investigated compounds were tested against the bacterial species by agar cup method and fungal species by the poison plate method. Synthesis of substituted 3-methyl-1H-pyrimido[6,1-b]quinazoline-1,10(4H)-dione (2a-e): These are synthesized by earlier known method. [8] 6-methylpyrimidine-2,4(1H,3H)-dione (0.05mole) is introduced in 50 ml of xylene and heated to 120-130o C. substituted isatoic anhydride (1a-e) (0.05mole) were slowly added to the mixture with continuous stirring. After the evolution of carbon dioxide has ceased, the temperature is raised to 140-150o C with simultaneous azeotropic removal of water. The heating is continued till no further water is formed. The reacting mixture is cooled, filtered, washed with methanol and then with warm water to obtain 2a-e. Procedure for synthesis of substituted 4-arylidene-3-methyl-1H-pyrimido[6,1-b]quinazoline-1,10(4H)-diones [4a-t]. A mixture of 3-methyl-1H-pyrimido[6,1-b]quinazoline1,10(4H)-diones (2a-e) (0.01\mole), aromatic aldehydes (3ad)(0.01 mole), piperidine 0.5ml and alcohol 5ml were taken in RBF. The reaction mixture is then refluxed for 6 hrs and then the content was poured on 200gms crushed ice. The resultant solid products4a-4twere filtered, washed and recrystallized by using absolute alcohol. The purity of 4-arylidene3-methyl-1H-pyrimido[6,1-b]quinazoline-1,10(4H)-diones (4a-t) were checked by TLC.