Synthesis and Characterization of Noval Heterocyclic Compounds

Abstract

2.2'-bis-7-substituted-[1,3,4]thiadiazolo-[2,3-b] quinazolin-5-one (3,4,5) were synthesized by action of 3-amino-2-mercaptoquinazolinone-4(3H)one with various dicarboxilic acids in the presence of phosphorousoxy chloride. The newly synthesized compounds have been characterized by analytical and spectral (IR, 1HNMR and Mass) properties. Further, they have been screened for their antimicrobial, anti-inflammatory (in vitro and in vivo) and analgesic activity by standard method.

Keywords

Fluorine, 1,3,4-Thiadiazolo, 3-amino-2-mercaptoquinazolinone-4(3H)one, Dicarboxilic acid

Introduction

The rapid progress of organic Fluorine chemistry [1-5] since 1950 has been translated as a pathfinder to invent useful biodynamic agents in Medicinal and Biochemistry.The new generation antibiotics like Norfloxacin, Ciproflaxacin, Flufloxacin, Sporfloxacin and Ofloxacin which were incorporated with fluorobenzene moiety proved their efficacy as potent bio active molecules.

Having witnessed from literature, the enormous importance of quinazolinones [6-16] and their derivatives and in continuation of our investigations on these compounds, it is thought useful to synthesize and characterize some new quinazolinone fused heterocycles.

For this purpose 3-amino-2-mercapto-4-(3H)-quinazolinone and their nuclear substituted analogoues are selected as SYNTHONS. It is aimed to build-up some biologically and pharmacologicaly potent heterocycles while making use of amino and mercapto groups of the synthon. The present work is thus designed to achieve the synthesis of 2,2'-bis-7 substituted [1,3,4] thiodiozolo [2,3-b] quinazolin-5-one.

In view of the associated biological and pharmacological properties of these heterocyclics, it is planned to screen them for their possible activities, in conjunction with quinazolinones.

Materials and Methods

Melting point was determined by open capillary tube method and are uncorrected. T.L.C was run on silica gel G plates using chloroform : ethanol [9:1] as developing solvent for the purity of the compounds. I.R. Spectra were recorded on Shimadzu FTIR Spectrophotometer by using NUJOL MULL technique.

The compound 3-amino-2-mercaptoquinazolin-4(3H)-one (2) was synthesized by adding carbondisulphide (1.6 m1. 0.026 mol) and aqueous sodium hydroxide (1.2 m1, 20M) dropwise to a vigorously stirred solution of anthranilic acid (1, 0.02 mol) in dimethylsulfoxide (10 ml) at room temperature. After thirty min dimethylsulphate (2.5g. 0.02 mol) was added dropwisc under cooling with an ice bath. Stirring was continued for 3h, the reaction mixture was then poured into icc water and extracted with chloroform. The solvent was removed by distillation under reduced pressure. Thus the obtained methyl-N-(2-carboxyphenyl) dithiocarbamate was used for further reaction without purification. Hydrazine hydrate (8.6g. 0.2 mol. 80%) was added dropwise with stirring to methyl-N-(2-carhoxyphenyl) dithiocarhamate in cold condition. After completc addition, stirring was continued for 1½ hr at 500C and then it was poured into ice water, the solid obtained was filtered, washed with water dried and recrystallized from dimethylformamide-ethanol mixture to yield (2) as a white crystalline product.

A mixture of compound (2, 0.02 mole) oxalic acid/ succinic acid/ tartaric acid/ maleic acid/ citric acid/ phthalic acid/(0.01 mole) and POCL₃ (15ml) was heated and reflux for 2-4 hrs while monitoring by TLC. Phosphorus oxychloride was removed from ensuring the completion of the reaction undr reduced pressure and cooled. The reduced pour on the crused ice (100g), while stirring the resultant solution was neutriilsed with sodium bicarbonate while cooling in ice bath. The precipitated soild was filteren, washed with cold water and dried. The crude product was recrystalise from dimethyl formamide.

Biological Activities

Anti-microbial Activity [17-24]

The synthesized compounds are screened against bacterias like staphylococcus aureus (Gram +ve) and Escherichia coli (Gram -ve) and Bacillus subtillis (Gram +ve) and Pseudomonas aureus (Gram -ve) and fungi like Candida albicans and Aspergillus flavus to know their antimicrobial activity (by cup plate method).

Anti-inflammatory activity (in-vitro) [25,26]

The synthesized compounds are screened for anti-inflammatory activity by using inhibition of albumin denaturation technique which was studied according to Jayachandran E. and G.M. sreenivasa with slight modification.

The standard drug and test compounds were dissolved in minimum amount of dimethyl formamide (DMF) and diluted with phosphate buffer (0.2 M, pH 7.4). Final concentration of DMF in all solutions was less than 2.0%. Test solution (1 ml) containing different concentrations of drug was mixed with 1 ml of 1% mM Bovine albumin solution in phosphate buffer and incubated at 27°±1°C in incubator for 15 min. Denaturation was induced by keeping the reaction mixture at 60°±1°C in water bath for 10 min. After cooling the turbidity was measured at 660 nm (UV-Visible Spectrophotometer SL-159, Elico India Ltd.). Percentage of inhibition of denaturation was calculated from control where no drug was added. Each experiment was done in triplicate and average was taken. The Ibuprofen was used as standard drug.

Results and Discussion

Antibacterial activity by cup-plate method

Synthesized compounds have been evaluated for antibacterial activity at concentration of 50 μg/ml and 100 μg/ml by standard method, against following bacteria:

a) (i) Streptococci (ii) Staphylococus aureus gram (+ve).

b) (i) Pseudomonas, (ii) Escherichia coli gram (-ve).

All the compounds have been shown to exhibit a moderate broad spectrum of activity. The test compounds have been found to active against both gram (+ve) and gram (-ve) organisms.

The test compounds DK-2, DK-7, DK-8, DK-17 showed superior in it's antibacterial activity at lower (50μg/ml) and DK-2, DK-7, DK-11, DK-12, DK-15 at higher (100μg/ml) concentration against Streptococci gram (+ve), compare to standard drug procaine pencillin.

Compounds DK-3, DK-4, DK-6, DK-10, DK-16, DK-17 at (50μg/ml) and DK-2, DK-4, DK-7, DK-9, DK-12, DK-15 at (100μg/ml) showed promising antibacterial activity against Pseudomonas gram (-ve), bacteria compare to standard drug streptomycin.

Compounds DK-3, DK-7, DK-10, DK-12, DK-15 at (50μg/ml) and DK-1, DK-3, DK-7, DK-9, DK-12, DK-15 at (100μg/ml) showed moderate activity against Staphylococcus aureus gram (+ve) bacteria compare to standard drug procaine pencillin.

The compounds DK-4, DK-6, DK-8, DK-10, DK-13, DK-17 at (50μg/ml) and DK-2, DK-4, DK-8, DK-10, DK-13, DK-15, DK-17 (100 μg/ml) being same has been found exhibit relatively by more in their inhibitory action against Escherichia coli gram (-ve) bacteria, compare to standard drug streptomycin.

Antifungal activity

All the compounds were subjected to antifungal activity. For these activities Candida albicans and Aspergillus flavus fungal organisms were used. The Griseofulvin was used as standard.

Standard and synthesized compound were tested at two cone. Viz., 50μg/ml and 100 μg/ml. The compounds have shown activity, but none of them have shown better activity than standard.

Some of compounds like DK-1, DK-2, DK-4. DK-9, DK-11, DK-14 and DK-15 have shown activity almost equal to standard against Candida albicans at 100μg/ml cone. and DK-1, DK-8, DK-11 and DK 15 have shown activity near to standard at 50μg/ml conc. and the compounds DK-1, DK-2, DK-7 and DK-11, have shown activity near to standard against Aspergillus flavus organism at 100μg/ml cone. and DK-1, DK-2, DK-7, DK-8 and DK-11 at 100μg/ml conc. The remaining compounds have shown very low activity.

From this it is concluded that the synthesiled compounds have shown better activity agtainst Aspergillius flavus than Candida albicans.

Anti-inflammatory activity (in vitro model)

Synthesized compounds of 2,2'-bis-7 substituted-[1,3,4]-thiadiazolo-[2-3-b] quinazolin-5-ones have been evaluated for anti-inflammatory activity (in-vitro). Some of compounds promisingly inhibit albumin denaturation in comparison with standard drugs, ibuprofen exhibited 74.63% inhibition of albumn denaturation.

However eight out of eighteen compounds having more than 40% inhibition of albumin denaturation. Out of that DK-2, DK-3, DK-4, DK-6. DK-10, DK-12. DK13 and DK-14 showed 48.54%, 45.65%, 73.91%, 71%, 70.28%, 71.74%, 72.46% and 41.30% inhibition of albumin denaturation.

Acknowledgement

The authors are thankful to Shri. Sha. Bra. Chandramouleshwara Shivacharya Swamiji, President, Sri. T. M. Chandrashekaraiah M.A. Secretary, T.M.A.E. Society Harapanahalli. for providing necessary facilities through the Principal, S.C.S. college of Pharmacy, Harapanahalli to carry out this work.

References

1. Feller.R Biologically active fluoro chemicals J. Fluorine Chem 1986; 33: 361-375
2. Greco Micheal N, Hangman William E. Synthesis of benzothiazole hydroxyl ureas as hibitors of 5-lipoxygenase enzymes; Chem Abstr 1992; 117; 131109 z.
3. Sutoris V. Synthesis of 3-(2-alkoxy carbomyl-ethyl) 2-benzothiazolinones and their regulating activity on the growth of Triticum Oestivum. Chem Abstr. 1991;106:83584f
4. Woltersdrof OW Jr, Schwam H, Bicking JB, Brown SL, DeSolms SJ, Fishman DR, et al. Topically active carbonic anhydrase inhibitors1-o-acyl derivatives of 6-hydroxy benzothiazol 2-Sulfonamide. Chem Abstr. 1989; 111:194656x
5. Scholewald, Ronald D. Sulfonamido benzothiazole derivatives as topical carbonic anhydrase inhibitors. Chem Abstr. 1984; 100:2069678c
6. Narayan UL, Nerkar AG, Panda CS. Synthesis and screening of 6,6’-methyl-3-[2’-aryl-thiazolindin-4’one]/[2’-aryl-imidazolidin-4’one]quinazoline-4-(3H)-ones for antibacterial and antifungal activities. Int J Chem Sci. 2006; 4(1): 93-100.
7. Pattan SR, Reddy VVK, Pattan JS, Venkataramanna NV, Prajapati PN, Hemashettar BM. Synthesis and microbiological evaluation of N’-3(4-(4-chloro-phenyl)thiazolo-2-yl)quinazoline-4-(3H)-ones. Ind J Hetero Chem. 2005; 15: 79-80.
8. Hitesh D Patel, Mistry BD, Desai KR. Synthesis and antimicrobial activity of imidazole quinazoline; Oriental J Chem. 2003; 19(2): 393-398.
9. Marzoog S Al-Thebeiti, Maher F El-Zohry. Synthesis of some new spirothiazolidinone and spirozetidinone derivatives incorporated with quinazoline. Ind J Chem. 1998; 37B: 804-809.
10. Sharma RL, Surinder Kumar, Anand Sachar, Jasbir Singh, Daljeet Kour. Synthesis of 1,2,4-triazolo,tetrazolo and pyrazolylquinazolines. Ind J Hetero Chem. 2005; 15: 101-104.
11. Bhardwaj V, Gupta VN, Suri OP. Synthesis of 11H-pyrido[2,1-b]quinazolin-11-ones; Ind J Heter Chem 1999; 8: 173-176.
12. Trilok Chandra, Neha Garg and Ashok Kumar. Synthesis of Sulpha Drug Quinazolin -4-one Derivatives and Their Evaluation for Anti-inflammatory Activity. W J of Chem . 2009;4 (2): 210-218.
13. Peyman Salehi, Minoo Dabiri, Mohammad Ali Zolfigol and Mostafa Baghbanzadeh. A new approach to the facile synthesis of mono- and disubstituted quinazolin-4(3H)-ones under solvent free conditions. Tetrahedron Lett. 2005; 7051–7053.
14. Kale AU, Kardile DP, Kalyane NV, Patel MR, Patel H. Synthesis and antimicrobial activity of some 2, 3-disubstituted quinazoline-4(3h)-ones. Int J Pharma Applied Sci. 2010;(1)
15. Deepti Kohli, Riaz Hashim S., Sagar Vishal, Manish Sharma and Ashutosh Kumar Singh. Synthesis and antibacterial activity of quinazolinone derivatives. Int J Pharm Pharm Sci. 2009;1.
16. Mohammed Abdalla Hussein. Structure anti-inflammatory activity relationship and biochemical evaluation of some novel triazoloquinazoline and triazinoquinazoline derivatives containing sulfacetamide moiety. IJABPT.2010; I: 3: Nov-Dec
17. Robbert D, Smyth. Clinical analysis, Microbiology, Remington’s Pharmaceutical sciences, 18th ed. Mack Publishing company, peninisilvenia. 1991: 524-27.
18. European Committee for Antimicrobial Susceptibility Testing (EUCAST) of the European Society of Clinical Society of Clinical Microbiology and Infectious Diseases (ESCMID) 2000.
19. Peclzar, Reid, Cohn. Antibiotics and other chemotherapeutic agents Microbiology, TMH edn, TATA-Mcgraw-Hill Publishing House 1989; 466-93.
20. Jayachandran E, Nargund LVG, Shivakumar S, and Kamal Bhatia. Sythesis and Phamacological screening of 2 – [3-amino 5-s-methyl-4-carboxamido, Pyrozol-1-yl] 6-fluoro, 7-substituted (1,3) benzothaizoloes. Oriental J of Chem. 2003; 19(1) 139-142.
21. Gurupadaiah BM, Jayachandran E, Shivakumar B, Nagappa AN, Nargund LVG. Synthesis of Fluorobenzothaizolo sulphonamides and their Anti-bacterial activity. Ind J Heter Chem. 1998; 7:213-216
22. Basavaraj HS, Sreenivasa GM, Jayachandran E, Nargund LVG, Sreenivasa Rao D. Syntheisis of substituted pyrimidino imidazolinones as Antimicrobial agents. Indian J Hetrocyclic Chem. 2005; 15: 69-70.
23. Nagendra Rao R, Jayachandran E, Sreenivasa G M, Jyothi T M. Synthesis and screening of substituted Benzoxazoles and benzoxazolo trizoles. Oriental J Chem. 2005; 21(2): 327-330.
24. Perumal R, Jayachandran E, Naragund LVG, Shivakumar B, Sreenivasa GM, Shankraiah MM. Synthesis of 3-substituted, 1N-substituted phenyl pyrazolo-5-amino-4-carboxamido derivatives for pharmacological activity, Orint J Chem. 2005; 21(2): 377-378.
25. Srinivasa GM, Jayachandran E, Shivakumar B, Sreenivasa Rao D. Synthesis and pharmacological screening of 2-[3-amino,5-s-met carboxamido pyrazol-1-yl]6-fluoro,7-substituted (1,3)benzothiazole. Orint J Chem, 2004; 20(1); 103-110.
26. Sreenivasa Rao D, Jayachandran E, Sreenivasa GM and Shivakumar B. Inhibition of albumin denaturation and anti-inflammatory activity of 2-[N-p-Tolyl sulphon hydrazino]-6-fluoro-7-substituted (1, 3) benzothiazoles. Orint J Chem. 2005; 21(1), 113-116.