*Corresponding Author: Received 18 June 2013; Accepted 22 July 2013

Transcription

1 Available online at ISSN: ; 2013 IJSRPUB Full Length Research Paper Solvent-free Synthesis and Spectral Studies of Some 9-Anthryl- 1 H-Pyrazolines Krishnamoorthy Guna Sekar 1,*, Ganesamoorthy Thirunarayanan 2 1 Department of Chemistry, National College, Tiruchirappalli , India 2 Department of Chemistry, Annamalai University, Annamalainagar , India *Corresponding Author: drkgsekar@yahoo.co.in; drgtnarayanan@gmail.com Received 18 June 2013; Accepted 22 July 2013 Abstract. Totally ten 3-(9-anthryl)-4,5-dihydro-5-(3-substitutedphenyl)- 1 H-pyrazolines have been prepared by solvent-free cyclization of 2(E)-1-(substituted phenyl)-3-(9-anthryl)-2-propen-1-ones and hydrazine hydrate in presence of fly-ash:h 2 SO 4 catalyst. These pyrazolines were characterized by their physical constants and spectroscopic data. The assigned infrared νc=n, NH(cm -1 ), NMR chemical shifts(ppm) of δnh, H 4, H 4, H 5 and C=N data are correlated with Hammett substituent constants, F and R parameters using regression analysis. From the results of statistical analysis, the effects of substituent on the above group frequencies have been discussed. Key words: Solvent-free synthesis; 1 H-Pyrazolines; IR and NMR spectra; Hammett correlations 1. INTRODUCTION The 1 H-pyrazolines are bi-nitrogen five membered heterocyclic compounds. The substituted 1 H- pyrazoles have important biological activities due to the presence of N-N=C moiety in the pyrazoline ring (Rahman and Siddiqui, 2010; Elguero et al., 1984). The important biological activities are analgesic, antiinflammatory, anti-microbial (Sahu et al., 2008; Amir et al., 2008), anti-amoebic, (Abid and Azam, 2006), anti-tubercular (Shahar Yar et al., 2007), antidepressant and anti-convulsant activities (Ozdemir et al., 2007). Numerous solvent assisted and solventfree synthetic methods are reported for the synthesis of pyrazoline derivatives (Levai, 2005; Siddiqui et al., 2011; Azarifar and Ghasemnejad, 2003). Now-a-days scientist and chemists preferred solvent-free synthetic methods, due to the less hazardousness, lesser amount of solvent usage, unpolluted for the environment, easy handling procedure, shorter reaction time and higher yields (Sasikala et al., 2012; Thirunarayanan et al., 2013; Thirunarayanan and Sekar, 2013a; Siddiqui et al., 2011; Azarifar and Ghasemnejad, 2003). Many catalysts were employed for the synthesis of pyrazoline derivatives by solvent assisted or solventfree methods such as Lewis-acids, bases and their salts, aprotic organic acids (Sarkar et al., 2011; Kalirajan et al., 2009; Misra and Sasmal, 2011), flyash:h 2 SO 4 (Sasikala et al., 2012), pre-heated fly-ash some (Thirunarayanan and Sekar, 2013a), fly-ash:pts (Thirunarayanan and Sekar, 2013b), SiO 2 -H 3 PO 4 (Thirunarayanan et al., 2013) with microwave irradiation and ultrasound (Pizzuti et al., 2009). Spectroscopic data are utilized for prediction of ground sate equilibration of organic molecules such as 299 unsaturated ketones, aldehydes, alkenes, alkynes, acyl halides and its esters (Sathiyamoorthy et al., 2013). The effect of substituents on the functional group of the molecules can be evaluated by the correlation of the respective spectral group frequencies with Hammett substituent constants, F and R parameters using linear regression analysis (Shorter, 1973). The correlation analysis is applied for the study of electrochemical behaviour of organic molecules, E, Z, s-cis- and s-trans configuration and isomers of unsaturated systems, cis- and gauche- forms of rotomers of ω-halo acyl compounds( Thirunarayanan et al., 2011). Sasikala et al. (2012) have synthesised some 5-bromo-2-thienyl based pyrazoline derivatives by solvent-free method and studied the antimicrobial activities. Sakthinathan et al. (Sakthinathan et al., 2012) have synthesised and studied the effects of substituent on 2-naphthyl based pyrazolines. Ranganathan et al. (2012) have studied the effects of substituents and solvent-free synthesis of some 5- bromo-2-thienyl based pyrazolines. The solvent-free synthesis and the Hammett linearity on some pyrazoline-1-carbothioamides have been studied by Thirunarayanan and Sekar (2013a, b). Within the above view there is no information available about solvent-free synthesis and the study of spectral linearity on 9-anthryl based 1 H-pyrazolines. Therefore the authors have taken efforts to synthesize 3-(9-anthryl)-4,5-dihydro-5-(substituted phenyl)- 1 H-pyrazolines by solvent-free cyclization of substituted styryl 9-anthryl ketones and hydrazine hydrate and record their infrared and NMR spectra for studying the effect of substituents.

2 Sekar and Thirunarayanan Solvent-free Synthesis and Spectral Studies of Some 9-Anthryl-1H-Pyrazolines 2. EXPERIMENTAL 2.1. General All chemicals used were procured from Sigma- Aldrich and Merck chemical companies. The fly-ash was collected from Thermal-II, Neyveli Lignite Corporation, Neyveli, Tamilnadu. The infrared spectra of all pyrazolines were recorded with KBr discs in SHIMADAZU Fourier Transform spectrophotometer. The NMR spectra of all synthesised compounds were recorded in BRUKER AV400 NMR spectrometer applying 400 MHz for 1 H and 100MHz frequencies for 13 C NMR spectra using CDCl 3 solvent and tetramethylsilane as standard. The mass spectra of all pyrazolines were recorded in SHIMADZU spectrometer using chemical ionization technique Preparation and characterization of fly-ash: H 2 SO 4 catalyst The fly-ash: H 2 SO 4 catalyst was prepared by the procedure published in literature (Thirunarayanan et al., 2012). In a 50 ml Borosil beaker, 1 g of Fly-ash and 0.8 ml (0.5 mol) of sulphuric acid were taken and mixed thoroughly with glass rod. This mixture was heated on a hot air oven at 85 C for 1 h, cooled to room temperature, stored in a Borosil bottle and tightly capped. This was characterized by infrared spectra and SEM analysis. Infrared spectral data of fly-ash: H 2 SO 4 is ν (cm -1 ): 3456(OH); 3010 (C-H); 1495, 1390(C-S); 1336, 1154(S=O); and op modes: 1136, 1090, 976, 890, 850, 820, 667, 658, 620, 580, 498, 425. The SEM images of pure Fly-ash and Fly-ash: H 2 SO 4 at two different magnifications are shown in Fig. 1(a d). Figures 1a and 1b depicted that the crystallinity is found to be more in pure fly ash. The spherical shaped particles are clearly seen at both magnifications in Fig 1a and 1b. Fig. 1a reveals that the globular structure of pure fly ash (round shaped particle). This also seen from Fig. 1c and 1d that some of the particles are slightly corroded by H 2 SO 4 (indicated by arrow mark) and this may be due to dissolution of Fly-ash by H 2 SO 4. This will further confirmed by Fig 1d, the well-shaped particles of pure Fly-ash. Fig 1b is aggregated to Fig 1d due to presence of H 2 SO 4. Fig. 1: SEM images of fly-ash: H 2 SO 4 catalyst 300

3 2.3. Synthesis of 1 H-pyrazolines Appropriate equi-molar quantities of E-1-(substituted phenyl)-3-(9-anthryl) ketones (0.2 mmol), hydrazine hydrate (0.2 mmol) and 0.5 g of fly-ash: H 2 SO 4 were taken in a borosil glass tube and closed with lid. These contents were subjected to microwave irradiation (Scheme 1) for 4-6 m at 550W in a microwave oven (Samsung Grill, GW73BD Microwave oven, 230 V A/c, 50 Hz, 2450 Hz, W (IEC-705). The completion of reaction was monitored by Thin Layer Chromatogram. The reaction mixture was cooled to room temperature, extracted with 10 ml of dichloromethane. Evaporation of dichloromethane afforded the crude product. Further it is purified by crystallization with ethanol. The solid catalyst was reused for further reaction runs. The analytical, physical constants and mass fragments data are presented in Table 1. Scheme 1: Solvent-free synthesis of 3-(9-anthryl)-5-(3-substituted phenyl)-4,5-dihydro- 1 H-pyrazolines Table 1: Analytical, physical constants and mass fragments (m/z) of 3-(9-anthyl)-4,5-dihydro-5-( substituted phenyl)- 1 H- pyrazolines [a] = (Misra and Sasmal, 2011) 301

4 Sekar and Thirunarayanan Solvent-free Synthesis and Spectral Studies of Some 9-Anthryl-1H-Pyrazolines 3. RESULTS AND DISCUSSION 3.1. Infrared spectral study In the present study on infrared correlaion, we recorded the infrared spectra of ten synthesised 3-(9- anthryl)-4, 5-dihydro-5-(substituted phenyl)- 1 H- pyrazolines, assigned the νnh and C=N (cm-1) stretching frequencies as presented in Table 2. The assigned frequencies are subjected to correlate with Hammett substituent constants, F and R parameters using single and multi-regression analysis (Swain and Lupton, 1968). In infrared spectral correlations, the Hammett equation was taken as shown in equation (1). ν = ρσ + ν o (1) where ν is the frequency of the pyrazoline series, ρ is the slope with the meaning of linear coefficient, σ is the constant in the Hammett equation and ν o is the frequency of parent member of the pyrazoline series. Table 2: The infrared and nuclear magnetic resonance spectral data of 3-(9-anthyl)-4,5-dihydro-5-( substituted phenyl)-1hpyrazolines The results of statistical analyses (Sakthinathan et al., 2012; Sathiyamoorthy et al., 2013; Thirunarayanan et al., 2013; Thirunarayanan and Sekar, 2013a, b) are given in Table 3. From Table 3, the correlation of νnh(cm -1 ) frequencies were satisfactory with Hammett σ, σ I constants and F parameters excluding H, 3-and 4-CH 3 substituents. The remaining Hammett substituent constants and R parameters showed poor correlation. This was due to the polar and resonance effects of the substituents unable to predict the reactivity on the NH stretches and it was associated with the resonance-conjugative structure as shown in Fig. 2. The νc=n frequencies correlation was satisfactory with Hammett substituent constants and F and R parameters excluding 3- and 4- CH 3 substituents. All correlations related with νc=n frequencies gave positive ρ values. This means that the normal substituent effect operates in all pyrazoline systems. Some of the single parameter correlation of infrared frequencies of the synthesised pyrazolines has shown poor correlation. While seeking the multiregression analysis, these stretches satisfactorily correlated with Swain-Lupton s (Swain and Lupton, 1968) constants and F and R parameters. The generated multi-correlation equations (2-5) are; νnh(cm -1 ) = (±37.948) σ I (±84.171) σ R (±4.621) (2) (R = 0.969, P > 95 %, n = 10) νnh(cm -1 ) = (±40.710) F (±88.127) R (±6.996) (3) (R = 0.970, P > 95 %, n = 10) νc=n(cm -1 ) = (±3.886) σ I (±8.620) σ R (±8.921) (4) (R = 0.980, P > 95 %, n = 10) νc=n(cm -1 ) = (±4.117) F (±5.891) R (±7.041) (5) (R = 0.981, P > 95 %, n = 10) 302

5 H NMR spectral study The 1 H NMR spectra of synthesised 3-(9-anthryl)-4,5- dihydro-5-(substituted phenyl)- 1 H-pyrazoline derivatives under spectral correlation study have been recorded in deuteriochloroform solvent employing tetramethylsilane (TMS) as internal standard. The signals of the 3-(9-anthryl)-4,5-dihydro-5- (substituted phenyl)- 1 H-pyrazoline NH and ring protons have been assigned. They are calculated as AB or AA' systems respectively. The chemical shifts (ppm) of H 4 are at higher fields than those of H 4 and H 5 in this series of 3-(9-anthryl)-4,5-dihydro-3-(substituted phenyl)- 1 H-pyrazolines. This is due to the deshielding of H 4 and H 5 protons which are exist in different chemical as well as magnetic environment. These H 4 protons gave an AB pattern in all pyrazolines. The H 4 proton doublets of doublets are well separated from the signals H 5 and the aromatic protons. The assigned chemical shifts (δ,ppm) of the pyrazoline ring NH, H 4, H 4 and H 5 protons are presented in Table 2. In nuclear magnetic resonance spectra, the chemical shift (δ, ppm) depends upon the electronic environment of the nuclei concerned. These assigned chemical shifts were correlated with reactivity parameters. In this correlation, the Hammett equation may be used in the form as, log δ= log δ 0 + ρσ (8) where δ is the chemical shift of the series, ρ is the slope, σ is the Hammett sigma constants and δ 0 is the chemical shift of the parent compound of the series. The assigned NH, H 4, H 4 and H 5 proton chemical shifts (ppm) of synthesized 3-(9-anthryl)-5- (substituted phenyl)-4,5-dihydro-1h-pyrazolines were correlated with Hammett sigma constants, F and R parameters. The NH, proton chemical shifts (δ, ppm) have shown poor correlation with Hammett substituent constants, F and R parameters. The H 4, protons chemical shifts (δ, ppm) correlation was satisfactory with Hammett σ I constants and F parameters along with positive ρ values. The H 4 proton chemical shifts (δ, ppm) of the pyrazolines gave satisfactory correlation with F parameters excluding 2-OH and 4-OCH 3 substituents. The remaining Hammett substituent constants and R parameters were failing in correlation. The H 5 proton chemical shifts (ppm) of synthesized 3-(9-anthryl)-5- (substituted phenyl)-4,5-dihydro- 1 H-pyrazolines have shown poor correlation with Hammett substituent constants, F and R parameters. The reason for failure in correlation was stated earlier and associated with the resonance-conjugative structure shown in Fig. 2. In view of the inability of the NH, H 4, H 4 and H 5 proton chemical shifts (ppm) of synthesized 3-(9- anthryl)-5-(substituted phenyl)-4,5-dihydro-1hpyrazolines to produce satisfactory correlation individually with Hammett, substituent constants, F and R parameters, the authors think that it is worthwhile to seek multiple correlations involving either σ I and σ R constants or Swain-Lupton s(swain and Lupton, 1968) F and R parameters. The multiregression correlated equations for NH, H 4, H 4 and H 5 proton chemical shifts (δ, ppm) are given in (9)-(16): δnh(ppm) = 9.261(±0.266) (±0.059)σ I 1.197(±0.061)σ R (9) (R = 0.973, P > 95 %, n = 10) δnh(ppm) = 9.217(±0.303) (±0.657) F (±0.051) R (10) (R = 0.969, P > 95 %, n = 10) δh 4 (ppm) = 2.758(±0.252) (±0.559)σ I 0.395(±0.052)σ R (11) (R = 0.960, P > 95 %, n = 10) δh 4 (ppm) = 2.754(±0.282) (±0.611) F (±0.040) R (12) (R = 0.957, P > 95 %, n = 10) δh 4 (ppm) = 3.591(±0.046) (±0.102)σ I 0.294(±0.106)σ R (13) (R = 0.979, P > 95 %, n = 10) δh 4 (ppm) = 3.580(±0.056) (±0.112) F (±0.097) R (14) (R = 0.973, P > 95 %, n = 10) δh 5 (ppm) = 6.163(±0.181) (±0.040)σ I (±0.041)σ R (15) (R = 0.905, P > 90 %, n = 10) δh 5 (ppm) = 6.106(±0.194) (±0.042) F (±0.033) R (16) (R = 0.917, P > 90 %, n = 10) 303

6 Sekar and Thirunarayanan Solvent-free Synthesis and Spectral Studies of Some 9-Anthryl-1H-Pyrazolines Table 3: Results of statistical analysis of infrared ν(cm -1 ) NH, C=N, NMR chemical shifts (δ, ppm) of NH, H 4, H 4, H 5, NH and C=N of 3-(9-anthryl-5-(substituted phenyl)-4,5-dihydro- 1 H- pyrazole with Hammett σ, σ +, σ I σ R constants and F and R parameters. r = correlation co-efficient; ρ = slope; I = intercept; s = standard deviation; n = number of substituents 304

7 Fig. 2: The resonance-conjugative structure C NMR spectra Chemists and researchers (Sakthinathan et al., 2012; Sathiyamoothry et al., 2013; Thirunarayanan et al., 2013; Thirunarayanan and Sekar, 2013a, b) have made extensive study of 13 C NMR spectra many of ketones, styrenes and keto-epoxides. They investigated the linear correlation of the chemical shifts with Hammett substituent constants, F and R parameters. The good, satisfactory and fair degree of correlations was obtained in their investigations. In the present investigation, the C=N carbon chemical shifts (δ, ppm) of 3-(9-anthryl)-5-(substituted phenyl)- 4,5-dihydro- 1 H-pyrazolines have been assigned and are presented in Table 2. Attempts have been made to correlate the assigned C=N carbon chemical shifts (δ, ppm) with Hammett substituent constants, field and resonance parameters with the help of single and multi-regression analysis for the prediction of substituent effects. From Table 3, the C=N chemical shifts (δ, ppm) has shown satisfactory correlation with Hammett σ, σ + and σ I, substituent constants and F parameters excluding 4-Cl substituents. The Hammett σ R constants and R parameters gave poor correlation. The multi-regression analysis of these C=N chemical shifts (δ, ppm) gave satisfactory correlation with Swain-Lupton s (Swain and Lupton, 1968) parameters. The correlated equations are given in (17 and 18). δc=n(ppm) = (±1.422) (±3.155)σ I 0.491(±0.137)σ R (9) (R = 0.977, P > 95 %, n = 10) δc=n(ppm) = (±1.455) (±3.152) F (±0.024) R (10) (R = 0.980, P > 95 %, n = 10) 4. CONCLUSION A series of more than 90% yields of 3-(9-anthyl)-4,5- dihydro-5-(substituted phenyl)- 1 H-pyrazolines were synthesised by fly-ash:h 2 SO 4 catalyzed solvent-free cyclization of (E)-3-(9-anthryl)-5-(substituted phenyl)-2-propen-1-ones and hydrazine hydrate under microwave irradiation. These pyrazolines were characterised by their physical constants and spectral data. The assigned spectral frequencies and chemical shifts of the pyrazolines were correlated with Hammett Substituent constants, F and R parameters. The regression analysis shows satisfactory correlations with these spectral frequencies. REFERENCES Abid M, Azam A (2006). Synthesis characterization and antiamoebic activity of 1-(thaiazolo [4,5- b]quinoxaline-2-yl)-3-phenyl-2-pyrazoline 305 derivatives. Bioorg. Med Chem Lett., 16: Amir M, Kumar H, Khan SA (2008). Synthesis and pharmacological evaluation of pyrazoline derivatives as new anti-inflammatory and analgesic agents. Bioorg. Med. Chem. Lett., 18: Azarifar D, Ghasemnejad H (2003). Molecules, Microwave-Assisted Synthesis of Some 3,5- Arylated 2. Pyrazolines. Molecules, 8: Elguero J, Bulton, In, Mckillop (editors) (1984). Comprehensive Heterocyclic Chemistry, Pergamon Press. 5, 293. Kalirajan R, Sivakumar S U, Jubie S, Gowramma B, Suresh B (2009). Synthesis and Biological evaluation of some heterocyclic derivatives of Chalcones. Int. J. Chem Tech. Res., 1(1):

8 Sekar and Thirunarayanan Solvent-free Synthesis and Spectral Studies of Some 9-Anthryl-1H-Pyrazolines Levai A (2005). Synthesis of chlorinated 3,5-diaryl-2- pyrazolines by the reaction of Chloro chalcones with hydrazines. Arkivoc., 9: Misra N, Sasmal D (2011). Development of selective and reversible pyrazoline based MAO-B inhibitors: Virtual screening, synthesis and biological activities. Bioorg. Med. Chem. Lett., 21: Ozdemir Z, Burak Kandilci H, Gumusxel B, Calısx U, Altan Bilgin A(2007). Synthesis and studies on antidepressant and anticonvulsant activities of some 3-(2-furyl)-pyrazoline derivatives. Eur. J. Med. Chem., 42: Pizzuti L, Piovesan LA, Flores AF, Quina FH, Pereira CMP (2009). Environmentally friendly sonocatalysis promoted preparation of 1- thiocarbomyl-3,5- diaryl-4,5-dihydro-1hpyrazoles, Ultrasonics Sonochemistry 16: Rahman AMd, Siddiqui AA (2010). Pyrazoline Derivatives: A Worthy Insight into the Recent Advances and Potential Pharmacological Activities. Int. J. Pharm.Sci.Drug Res, 2(3): Ranganathan K, Arulkumaran R, Kamalakkannan D, Sundararajan R, Sakthinathan S P, Vijayakumar S, Suresh R, Vanangamudi G, Thirumurthy K, Mayavel P, Thirunarayanan G (2012). Silica-H2SO4 catalyzed environmentally benign crossed aldol condensation: Synthesis, spectral studies and biological activities of some 5-chloro-2-thienyl chalcones. Int. J. Pharm. Med. Biol. Sci., 1(1): Sahu SK, Banerjee M, Samantray A, Behera C, Azam MA (2008). Synthesis, Analgesic, Antiinflammatory and Antimicrobial Activities of Some Novel Pyrazoline Derivatives. Trop. J. Pharm. Res., 7(2): Sakthinathan SP, Vanangamudi G, Thirunarayanan G (2012). Synthesis, spectral studies and antimicrobial activities of some 2-naphthyl pyrazoline derivatives, Spectrochim. Acta. 95A: Sarkar BK, Patel R, Bhadoriya U (2011). Antimicrobial Activity of Some Novel Pyrazoline Derivatives. J. Adv. Pharm. Edu. Res., 1(5); Sasikala S, Thirumurthy K, Mayavel P, Thirunarayanan G (2012)Eco-friendly synthesis and antimicrobial activities of some 1-phenyl-3- (5-bromothiophen-2-yl)-5-(substituted phenyl)- 2-pyrazolines. Org. Med. Chem. Lett., doi: / Sathiyamoorthi K, Mala V, Palanivel Sakthinathan S, Kamalakkannan D, Suresh R, Vanangamudi G, Thirunarayanan G (2013). Solvent-free synthesis, spectral correlations and antimicrobial activities of some aryl E 2- propen-1-ones. Spectrochim Acta. 112A: Shahar Yar M, Ahmad Siddiqui A, Ali M A (2007). Synthesis and antimycobacterial activity of novel heterocycles. J. Serb, Chem. Soc., 72(1): Shorter J (1973). Correlation analysis in organic Chemistry: An introduction to linear free energy relationships, Clarendon Press, London. Siddiqui ZB, Farooq F, Mohammed Mustafa TN (2011). A highly efficient, simple, and ecofriendly microwave-induced synthesis of indolyl chalcones and Pyrazolines. Green Chemistry Letters and Reviews, 4(1): Swain CG, Lupton JREC (1968). Field and resonance components. in substituent effects. J. Am. Chem. Soc., 90: Thirunarayanan G, Vanangamudi G, Sathiyendiran V, Ravi K (2011). Solvent free synthesis, spectral studies and antioxidant activities of some 6- substitued -bromo-2-naphthyl ketones and their esters. Indian J. Chem., 50B(4): Thirunarayanan G, Mayavel P, Thirumurthy K. (2012). Fly-ash: H 2 SO 4 catalyzed solvent free efficient synthesis of some aryl chalcones under microwave irradiation. Spectrochim Acta, 91A: Thirunarayanan G, Mayavel P, Thirumurthy K, Dineshkumar S, Sasikala R, Nisha P, Nithyaranjani A (2013). Eco-friendly synthesis and spectral correlations in some 1-phenyl-3-(5- bromothiophen-2-yl)-5-(substituted phenyl)-2- pyrazolines. Eur. Chem. Bull., 2(9): Thirunarayanan G, Sekar KG (2013a). Preheated flyash catalyzed cyclization of chalcones: Synthesis of some substituted pyrazole-1- carbothioamides and spectral correlations in 3- (3,4-dichlorophenyl)-5-(substituted phenyl)- 4,5-dihydro- 1 H-pyrazole-1-carbothioamides. Int. Lett. Chem. Phys. Astro., 10(1): Thirunarayanan G, Sekar KG (2013b). Synthesis of some substituted pyrazole-1-carbothioamides and spectral correlations in 3-(3,4- dibromophenyl)-5-(substituted phenyl)-4,5- dihydro- 1 H-pyrazole-1-carbothioamides, Q- Science Connect. DOI: 306

9 Associate Professor Dr.Krishnamoorthy GunaSekar obtained his first Degree from Bharathidasan University in National College, Tiruchirappalli in He later pursued Master s Degree in Chemistry in Bharathidasan University in National College,Tiruchirappalli in Dr. K. G. Sekar received his Master of Philosophy and Doctorate Degree in Chemistry from Annamalai University, Annamalainagar in 1993 and 1998.He has published over 50 referred articles in professional journals and currently sits as the reviewer for 2 international journals. His current research is focuses on physical organic chemistry and catalysis.. To data, he has published several scientific articles related to oxidation kinetics and synthesis of organic compounds. Dr. G. Thirunarayanan was completed his Master Degree of Chemistry with first class in Bharathidasan University, Tiruchirappalli , India. The M. Phil. and Ph. D. research degrees were persued in Annamalai University, Annamalainagar , India in the field of Physical Organic Chemistry in His primary area of research is Synthesis, Green synthesis, Catalysis, Spectral LFER studies and biological activities of Chalcones and their derivatives. At present Dr. G. T. is a Faculty Member as Assistant Professor (SS) of Chemistry in Annamalai University. He published more than 50 research articles in reputed referred national and international journals. 307