synthesis and spectroscopic characterization of heterocyclic schiff ...

BANGLADESH RESEARCH PUBLICATIONS JOURNALISSN: 1998-2003, Volume: 7, Issue: 4, Page: 386-391, November - December, 2012SYNTHESIS AND SPECTROSCOPIC CHARACTERIZATION OFHETEROCYCLIC SCHIFF BASE LIGANDM.B. Islam 1 *, Yu-Fei Song 2 and M. J. Hossain 3M.B. Islam, Yu-Fei Song and M. J. Hossain (2012). Synthesis and Spectroscopic Characterization of HeterocyclicSchiff Base Ligand. Bangladesh Res. Pub. J. 7(4): 386-391. Retrieve fromhttp://www.bdresearchpublications.com/admin/journal/upload/09357/09357.pdfAbstractTwo heterocyclic Schiff base ligands have been synthesized by thecondensation reaction of salicyalaldehyde and 2-pyridinecarboxaldehydewith widely used biologically important molecule 2-hydrazinobenzothyazole. The synthesized compounds were identified by1 HNMR spectroscopic techniques.Key words: Synthesis, Heterocyclic, Schiff base, benzothiazole, characterization.IntroductionOver the past few decades various classes of Schiff bases ligands havebeen extensively studied which can be prepared by condensation of differenttypes of amines and carbonyl compounds. The divers chelating ability ofpotential O, N-donors of salicylaldimines made them very popular among theresearcher (Long, 1995). Schiff base ligands have received more attention mainlybecause of their wide application in the field of catalysis and due to theirantibacterial (Chohan, et al., 1999; Gauri, et al., 2011) anti-tuberculosis (Mishra, etal., 2008), and antitumour activity (Jeeworth, et al., 2000), insecticidal activity(Mishra, et al., 2011). They easily form stable complexes with most transition metalions. The exploration of privileged structures in drug discovery has gainedsignificant popularity in medicinal chemistry over the past years. Heterocyclesplay an important role in the design and discovery of newpharmacologically active compounds (Natarajan et al., 2010). Heterocyclesbearing nitrogen, sulphur and thiazole moieties constitute the core structure of anumber of biologically interesting compounds (Sharma and Sharma, 2009).Benzothiazole and its derivatives (Mahran, et al., 2007; Russo, et al., 1994;baltork, et al., 2007; Katsura, et al., 1992; Kuhler, et al., 1998) have beenrecognized as a class of medicinal importance. Benzothiazoles have also beenscreened for their antituberculostic activity (Krasovskii, et al., 1977). Benzothiazolederivatives represent an extensive group of heterocyclic compounds, several ofwhich have already found application in the medical sphere as medicines(Kashiyama, et al., 1999) as well as in agriculture (Pulkrábek, et al., 1999;Henselová, et al., 2001). 2/3-Substituted-benzothiazoles and their derivatives haveattracted much attention of chemists and pharmacologists because of theirbroad spectrum biological activities and use as photographic materials (Thieron,et al., 1998; Thieron, et al., 1999; Nakahanada, et al., 1999). Many of 2-Rsubstituted benzothiazoles are known as substances with , antiviral (Pandeya,*Corresponding Author: badol02@yahoo.com1Drugs & Toxin Research Division, BCSIR Laboratories, Rajshahi-6206, Bangladesh2Beijing University of Chemical Technology, Beijing-100029, China3Chitagong Thermal Power Station,BPDB, Raozan, Chittagong, Bangladesh

Characterization of Heterocyclic Schiff Base Ligandet al., 1999; Selvam, et al., 2008), anthelmetic (Munirajasekar, et al., 2011),analgesic (Pramila, et al., 2008), antiinflamaory (Mathews, et al., 2007),anticytotoxic (Sirisoma, et al., 2009; Srivastava, et al., 1982), antibacterial andantifungal activities (Foltínová, et al., 1978; Grandolini, et al., 1986; Afsah, et al.,1996) and are reported also to be active as antineoplastics (Krieg, et al., 1996)agent. Schiff base complexes derived from heterocyclic compounds havefound increased interest in the context of bioinorganic chemistry (Chaviara,et al., 2004; Ciller, et al., 2009; Agarwal, et al., 1990).Keeping in view in this paper we report the synthesis of Schiff baseligands by the conventional condensation reaction of biological and clinicalimportance 2-hadrazinobenzothiazole with salicylaldehyde and 2-pyridinecarboxaldehyde and their structural characterization by 1 HNMR and TLC.Materials and MethodsExperimentalAll the chemicals and solvents used for the synthesis were reagent grade.Salicylaldehyde, 2-hydrazinobenzothiazole, and 2-pyridinecarboxaldehydeobtained from Fluka and Aldrich. All solvents were dried and purified before used.The purity of the compounds was controlled by thin layer chromatography(TLC). 1 H-NMR spectra were recorded using Varian-400 MHz spectrometer usingDMSO-d6 as a solvent. Chemical shifts are reported in parts per million downfieldfrom tetramethylsilane.Synthesis of ligandSynthesis of ligand (E) -1-(benzo[d]thiazol-2-yl)-2-(phenol-2-ylmethylene)hydrazine (L-S)A mixture of L (1.0 g, 6.06 mmol) and salicylaldehyde (0.776 g, 6.363 mmol)was refluxed in 80 mL ethanol for 4h at 80 0 C. The reaction mixture was allowed tocool. The deposited precipitate was filtered off, washed with diethylether anddried to produce L-S in good yield, as a greenish white powder in 75% yield.387OHCHOSalicylaldehydeH 2 NHNSNL2-hydrazinobenzothiazoleReflux 4hFigure 1. Synthesis scheme of the ligand L-SEthanol, 80 COHNHNL-S(E)-1-(benzo[d]thiazol-2-yl)-2-(phenol-2-ylmethylene)hydrazineSynthesis of ligand (E) -1-(benzo[d]thiazol-2-yl)-2-(pyridin-2-ylmethylene)hydrazine (L-P)A mixture of L (1.0 g, 6.06 mmol) and 2-pyridincarboxaldehyde (0.681gm,6.363 mmol) was refluxed in 80 mL ethanol for 4h at 80 0 C. The reaction mixturewas allowed to cool. The deposited precipitate was filtered off, washed withdiethylether and dried to produce L-P in good yield, as a off white powder in 79%yield.SNhttp://www.bdresearchpublications.com/journal/

Islam et.al.388NCHO2-pyridinecarboxaldehydeH 2 NHNSNL2-hydrazinobenzothiazoleReflux 4hrEthanolNNHNL-P(E)-1-(benzo[d]thiazol-2-yl)-2-(pyridin-2-ylmethylene)hydrazineSNFigure 2: Synthesis scheme of the ligand L-PResults and DiscussionsThe study presented here includes synthesis of heterocyclic Schiff base bycondensation of equimolar amount of two different aromatic and heterocyclicaldehydes and 2-hydrazinobenzothiazole in ethanol. The chemical structures ofthe synthesized compounds were confirmed on the basis of their 1 HNMR spectraldata and the purity was ascertained by TLC analysis.The 1 H NMR spectrum of the ligand in DMSO shown in Figure (3a.b and4a.b) and their signals given in Table 1 and 2. The phenyl multiplet of the Schiffbase ligand L-S is seen at 6.9 – 7.8 ppm whereas the phenyl and pyridyl muliplet ofthe ligand L-P is seen at 7.1- 7.9 ppm. In the case of ligand L-P the peak at 8.6ppm as doublet is ascertained for the pyridyl proton of 6 th postion. The peak at 8.5ppm in the ligand L-S is tentatively attributed as azomethine peak but the peak isseen at 8.1 ppm in the case of ligamd L-P.Table1. 1 HNMR Spectral data of the ligand L-SChemical shiftppmMultiplicity Number ofprotonsFunctional groupassigned6.9-7.8 Multiplet 4 Aromatic protons8.5 Singlet 1 -HC=N-Table 2. 1 HNMR Spectral data of the ligand L-PChemical shiftppmMultiplicityNumber ofprotonsFunctional groupassigned7.1-7.9 Multiplet 7Phenyl and pyridylprotons8.1 Singlet 1 -HC=N8.6 singlet 1Pyridyl proton of 6 thpositionLigand-L-SNHNSNOH(E)-1-(benzo[d]thiazol-2-phenol-2-ylmethylene)hydrazinehttp://www.bdresearchpublications.com/journal/

Characterization of Heterocyclic Schiff Base Ligand389Figure 3a. 1 HNMR spectra of Ligand L-SH 2 ODMSOFigure 3b. 1 HNMR spectra of dissolving solvent with residual water of Ligand L-SLigand L-PNNHN(E)-1-(benzo[d]thiazol-2-yl)-2-(pyridin-2-ylmethylene)hydrazineSNFigure 4a. 1HNMR spectra of Ligand L-Phttp://www.bdresearchpublications.com/journal/

Islam et.al.390H 2 ODMSOFigure 3b. 1 HNMR spectra of dissolving solvent with residual water of Ligand L-PAcknowledgementThe authors are thankful to the Chinese Government Scholarship Councilfor financial support and authorities of BCSIR for the grant of deputation in thisresearch work. Authors also thankful to the Brucker Company, Beijing, China forcooperation in getting the 1 HNMR spectral data.ReferencesAfsah, S.A. & Nayer, S.A. (1996). Asian J Chem., 8, 419.Agarwal, B.V. & Hingorani, S. (1990). Characteristics IR and electronic spectralstudies on novel mixed ligand complexes of copper (II) withthiosemicarbazones and heterocyclic bases. Synth. React. Inorg. Met-Org.Chem., 20:123-132Baltork, I.M., Khosropour, A.R & Hojati, S.F. (2007). Monatshefte fur Chemie -Chemical Monthly, 138, 663.Chaviara, A.T., Cox, P.J., Repana, K.H., Papi, R.M., Papazisis, K.T., Zambouli, D.,Kortsaris, A.H., Kyriakidis, D.A. &. Bolos, C.A. (2004). Copper (II) Schiff basecoordination compounds of dien with heterocyclic aldehydes and 2-amino-5-methyl-thiazole: synthesis,characterization, antiproliferative andantibacterial studies. Crystal structure of CudienOOCl2, J. Inorg. Biochem.98(8): 1271-1283Chohan, Z.H & Sheazi, S. A. (1999). Synth. React.Inorg. Met-Org Chem 29, 105-118.Ciller, J. A., Seoane, C., Soto, J.L. & Yruretagoyena, B.(2009). Synthesis ofheterocyclic compounds. Schiff bases of ethyl 2-amin of urancar oxylates.J.Heterocyclic. Chem. 23(5) : 1583-1586Foltínová, P., Sutoris, V. & Blockinger, G. (1978). Folia Microbiologica, 23, 225.Gauri, P. Deshapandea, Murlidhar, P. Wadekara, Vivek M. Rautb & GopalkrushnaH. M. (2011). J. Chem. Pharm. Res., 3(1):72-78.Grandolini, G., Ambrogi, V. & Rossi, C. (1986). J Med Chem., 21, 455.Henselová, M., Vizárová, G. & Macháčková, I. (2001). Rostlinná Výroba, 47, 411.Jeeworth, T. Wah, H.L.K.,Bhoeon M.G., Ghoorhoo, D. & Babooram, K. (2000).Synth React. Inorg met -org chem.., 30,1023-1034.Kashiyama, E., Hutchinson, I. & Chua, M. S. (1999). J Med Chem., 42, 4172.Katsura, Y., Inoue, Y., Nishino, S., Tomoi, M. & Takasugi, H. (1992). Chem Pharm Bull(Tokyo), 40, 1818.http://www.bdresearchpublications.com/journal/

Characterization of Heterocyclic Schiff Base LigandKrasovskii, A.N, Grin, A.N., Soroka, I.I., Kochergin, P.M & Bogamyreva, E.I. (1997).Pharma Chem J., 11(7), 900.Krieg, M. & Billitz, J. (1996), Molecular and Biochemical Pharmacology, 51, 1461.Kuhler, T.C., Swanson, M., Shcherbuchin, V., Larsson, H., Mellgard, B. & Sjostrom,J.E. (1998). J Med Chem., 41, 1777.Long, N. J. (1995). Angew. Chem. Int. Engl., 34, 21.Mahran, M.A, Abdel-Hamid, H. & El-Ashry E.SH. (2007) Alexandria J Pharma Sci.,2(1), 7.Mathews, M.E., Garden, S.J. & Fermades, P.D. (2007). Isatin inhibitcyclooxygenase-2 and inducible nitric oxide synthase in a mousemacrophase celliness; European Journal of Pharmacolology, 356, 206.Mishra, A. P. & Gupta, P. (2011). J. Chem. Pharm. Res., 3(2):150-161.Mishra, A. P., Khare M. & Gautam, S. K. (2008). Synth React. Inorg met -org chem.,32, 1485-1500.Munirajasekar, D., Himaja, M. & Sunil, M. (2011). Synthesis and antheminticactivity of 2-amino-6-subtituted benzothiazoles. International ResearchJournal of Pharmacy, 2(1); 114-117.Nakahanada, M. & Koho, J.K.T. (1999). JP 11 52, 530. 26 Feb, Chem. Abst. ,130:P202874b.Natarajan, U., Kaliappan, I., Kumar, N.S. (2010). Der Pharma Chemica, 2010, 2(1):159-167, http://derpharmachemica.com/archive.htmlPandeya, S.N, Sriram, D., Nath, G. & Clercq, D. E. (1999). synthesis antibacterialantifungal and anti HIV evaluation of Schiff and Mannich bases ofisatin with N-[6-chlorobenzothiazo-2-yl] thio semicarbazide, IndianJournal of Pharmaceutical Sciences, 61(6): 358Pramila, T., Bheemachari, V. Rajesh & Udupi, R.H. (2008). Condensed bridge headnitrogen heterocyclic systems synthesis and biological evaluation ofsubstituted-s-triazole-thiazzolethiones and s-triazolo-thiadiazinones, IndianJ Het Chem,17, 229.Pulkrábek, J., Šroller, J. & Zahradníček, J. (1999). Rostlinná Výroba, 45, 379.Russo, F., Romeo, G., Santagati, N.A., Caruso, A., Cutuli, V. & Amore, D.(1994). Eur J Med Chem., 29, 569.Selvam, P., Murugesh, N., Mohan, C.M. & Keyerts, E. (2008). Indian Journal ofPharmaceutical Sciences, 70(1):91-94.Sharma, V. & Sharma, K.V. (2009). Synthesis and Biological Activity of Some 3,5-Diaryl-1-benzothiazolopyrazoline Derivatives: Reaction of Chalcones with 2-Hyrazinobenzothiazoles, E-Journal of Chemistry, 6(2), 348-356.Sirisoma, N., Pervin, A., Drewe, J &Tseng, B. (2009).chemistry letters, 19; 2710-2713391Bio organic and medicalSrivastava, N., Gupta, A.A. & Anil, K. (1982). Synthesis and CNS activity of some 1-substituted amino methyl-3-[P-(N, N-diethyl carbamoyl) phenylimo]-substituted indolin-2-ones. Indian Journal of Chemistry; 21(B); 787Thieron, M. Pontzen, R. & Kurahashi, Y. (1999). Mod. Fungic. Antifungal Compd.,Int. Reihardsbrunn Symp. , 12th, p. 101.Thieron, M., Pontzen, R. & Kurahashi, Y. (1998). Pflanzenschutz-Nachr. Bayer, 51(3), 259.http://www.bdresearchpublications.com/journal/