Documents

www.ijirse.in_docs_ican14_ican84.pdf

Categories
Published
of 5
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Related Documents
Share
Description
(IJIRSE) International Journal of Innovative Research in Science & Engineering ISSN (Online) 2347-3207 Preparation of MnO 2 nanoparticles and application in the Synthesis of 2,2’-arylmethylene bis(3-hydroxy-5,5- dimethyl-2-cyclohexene-1-one) G. Harichandran* 1 , P. Parameswari 1 , S. David Amalraj 1 , P. Shanmugam 2 1 Department of Polymer Science, University of Madras, 2 Organic Chemistry Division, CSIR-Central Leather Research Institute, Adyar, Chennai, India E-mail: umhari@yahoo.co.in Abstr
Transcript
  (IJIRSE) International Journal ofInnovative Research in Science & Engineering  ISSN (Online) 2347-3207  Preparation of MnO 2 nanoparticles and application in the Synthesis of 2,2’ -arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) G. Harichandran* 1 , P. Parameswari 1 ,S. David Amalraj 1 ,P. Shanmugam 2 1 Department of Polymer Science, University of Madras, 2 Organic Chemistry Division, CSIR-Central Leather Research Institute, Adyar,Chennai, IndiaE-mail: umhari@yahoo.co.in  Abstract  —  Highlystable MnO 2 nano particlescatalyst has been preparedbyenvironmentally benignmethodandcharacterized by using Raman, XRD, FESEM, and EDAX techniques. The catalyticbehaviour ofnano crystallineMnO 2 has been demonstrated for the synthesis 2,2’ -arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) via Knoevenagel condensation of aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione under solvent-free conditions.Recyclability, high yield, short reactiontimeand easyworkup are the advantages of thepresentcatalyst.Keywords- MnO 2 NanoParticles,aryl aldehydes, 2,2’ -arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one)I.I NTRODUCTION 2,2 ′ -Arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one)compounds and theirderivatives aresignificantbio-active compoundsand have beenassessed as tyrosinase inhibitors[1]. Thesecompounds are keysynthons for thesynthesis of xanthenes that exhibitsignificantbiological and therapeutic activities such asantioxidants, lipoxygenase inhibitors, antibacterial and antiviralactivities [2], besides they are also used in lasertechnology[3].Several me thods have been reported for the syntheses of 2,2’ -arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) using a number of catalysts [4-11].Development of newer synthetic methodsbased on greenchemistry processes is increasingly of interest in organic synthesisdue to economic andenvironmental concerns.Solvent free heterogeneouscatalysis makes organic synthesis simple, saves energy, andprevents wastage of solvent, chemical hazards and toxicity [12].In general,MnO 2 isusedasanoxidizingagent[13]inorganic synthesis.However, tothebest ofourknowledge,MnO 2 nano particles(NPs)catalysedsynthesisof xanthene derivatives via a multicomponent reaction under solvent-free condition unknown.Thus, highlystable and environmentally benign MnO 2 NPshave beensynthesisedby hydrothermal methodandcharacterizedby using Raman, XRD, FESEM, and EDAX techniques. The catalytic behaviour of MnO 2 NPshas been demonstrated for the synthesis 2,2’ -arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) viaKnoevenagel condensation of aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione under solvent-freeconditions.The detail of the work is presented in this manuscript.II.M ATERIALS AND METHODS  A.Characterization Melting points were determined in open capillaries and are uncorrected. Chromatography purification wasconducted by column chromatography using silica gel. Solvents used for purification were of commercial gradeand were purified before use. 1 H and 13 C NMR spectra were recorded on a Brukerultra shield spectrometer(300and 75 MHz)or a JEOL-500MHz spectrometer (500 and 125 MHz) in CDCl 3 solvent using TMS as internalstandard.FESEM/EDAX analyses were carried out on a HITACHIS-3400N microscope.The phase compositionand crystalline natureof the catalyst was analyzed using PXRD.Bruker D8 ADVANCE MODEL diffractometerwas used for recording PXRD data between 2 theta values ranging from 20 and 70 deg using CuK α as sourceoperating at 40 kV and 30 mA. Raman spectra were recorded usinga BRUKERRFS 27: Stand-alone FT-RamanSpectrometer equipped with Nd: YAG 1064 nm as excitation source.  B.Preparation of theMnO 2  NPsCatalyst  MnO 2 NPshas beenprepared from commerciallyavailableMnO 2 (2g)powderwas treated with25 mL of 10M NaOH andpH =11was maintained.The mixture was then transferredinto a Teflon-lined stainless autoclave at180 °C for 48 h.After the reaction, the mixture was cooled to RT.Theresultedprecipitatewas washed withdistilled water and filteredand furtherwashed three times with 50 mL of10NHCl. After HClwashing, theprecipitatewasfurtherwashedwithdistilled waterand dried at 120°C for 6 hours andfinallycalcined at 400°Cfor 24 hours. The resultedMnO 2 NPscatalystwascrushed, powdered and usedfor reactions.  (IJIRSE) International Journal ofInnovative Research in Science & Engineering  ISSN (Online) 2347-3207  C.Procedure for the synthesis of 2,2'-arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one (  3 ) To a 25 mL RB flask, a2:1mixture of 5, 5-dimethylcyclohexane-1,3-dione 2 (2 mmol) and arylaldehyde 1 (1mmol)without any solvent was mixed withMnO 2 NPs(10mol%).The mixturewas heated at 100 °C for theappropriate period of time. After the completion of reaction (TLC monitoring), the reaction mixture was cooled toRT andEtOAc was added, and thecatalystwas filtered off. The filtrate was evaporated to dryness, and the solidobtained was further purified by column chromatography on silica gel (100  –  200 mesh)usinga mixture of petroleum ether and ethyl acetate (petroleum ether/ethyl acetate = 3/1, V/V) and/or recrystallization from ethanolto get pure products. The spectral data’s of selective compounds are presented below: 2,2’  -Phenylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) (  3a ) . 8 White crystalline solid; m.p.184  –  186 °C; FT- IR (KBr) ν max : 3388, 2962, 1588, 1370, 1254, 1156, 1098, 1031,811,577, 486 cm − 1 ; 1 HNMR (300 MHz, CDCl 3  /TMS)  δ H : 11.84 (s, 1H, OH), 7.22-7.01 (m, 5H, ArH), 5.47 (s,1H, CH), 2.37-2.27 (m, 8H,4(CH 2 ), 1.16 (s, 6H,2CH 3 ), 1.03 (s, 6H,2CH 3 ); 13 C NMR (75 MHz, CDCl 3  /TMS) δ C :189.4, 188.4, 137.1, 127.2, 125.8, 124.8, 114.6, 46.1, 45.4, 31.7, 30.4, 28.6, 26.4. 2,2'-[(4-Methylphenyl)methylene]bis(3-hydroxy-5,5-dimethylcyclohex-2-enone) (  3c ) . 8 White solid; m.p. 132-134  ℃; FT- IR (KBr) ν max : 2958, 2871, 1714, 1596, 1511, 1450, 1372, 1305, 1041,813cm − 1 ; 1 HNMR (500 MHz, CDCl 3  /TMS)  δ H : 11.84 (s, 1H, OH), 7.01-6.99 (m, 2H, ArH), 6.91-6.89 (m, 2H,ArH), 5.42 (s, 1H, CH), 2.40-2.21 (m, 11H,4(CH 2 ), CH 3 ), 1.15 (s, 6H,2CH 3 ), 1.02 (s, 6H,2(CH 3 ); 13 C NMR(125 MHz, CDCl 3  /TMS)  δ C :189.4, 188.3, 134.2, 133.8, 127.9, 125.6, 114.6, 46.0, 45.3, 31.3, 30.7, 28.6, 26.3,19.8. 2,2'-[(4-Chlorophenyl)methylene]bis(3-hydroxy-5,5-dimethylcyclohex-2-enone) (  3e ) . 8 White solid; m.p. 139-141  ℃ ,FT- IR (KBr) ν max :3435, 2958, 2872, 1595, 1490, 1468, 1374, 1304, 1253, 830cm -1 ; 1 HNMR (500 MHz, CDCl 3  /TMS)  δ H : 11.87 (s, 1H, OH), 7.23-7.22 (m, 2H, ArH), 7.02-7.00 (m, 2H, ArH),5.47 (s, 1H, CH), 2.48-2.28 (m, 8H,4(CH 2 ), 1.22 (s, 6H,2(CH 3 ), 1.09 (s, 6H,2(CH 3 ); 13 C NMR (125 MHz,CDCl 3  /TMS)  δ C :190.7, 189.4, 136.7, 131.5, 128.3, 128.2, 115.3, 47.0, 46.4, 32.4,31.4, 29.6, 27.4. 2,2'-[(4-Bromophenyl)methylene]bis(3-hydroxy-5,5-dimethylcyclohex-2-enone) (  3g ) . 8 White solid; m.p. 158-160  ℃ ;FT- IR (KBr) ν max :3447, 2955, 2869, 1597, 1471, 1419, 1377, 788, 725 cm -1 ; 1 HNMR (500 MHz, CDCl 3  /TMS)  δ H : 11.87 (s, 1H, OH),7.39-7.37 (m, 2H, ArH), 6.96-6.95 (m, 2H, ArH), 5.47(s, 1H, CH), 2.48-2.28 (m, 8H,4(CH 2 ), 1.21(s, 6H,2(CH 3 ), 1.09 (s, 6H,2(CH 3 ); 13 C NMR (125 MHz,CDCl 3  /TMS)  δ C :190.7, 189.4, 137.3, 131.3, 128.6,119.6, 115.2, 47.0, 46.4, 32.4, 31.4, 29.5, 27.4. 2,2'-[(4-Nitrophenyl)methylene]bis(3-hydroxy-5,5-dimethylcyclohex-2-enone) (  3i ) . 8 Yellow solid; m.p.190-192  ℃; FT- IR (KBr) ν max :3437, 2957, 2868, 1589, 1510, 1458, 1375, 1342, 1252,1167, 1153, 1044, 851, 733, 588, 492cm -1 ; 1 HNMR (500 MHz, CDCl 3  /TMS)  δ H :11.80(s, 1H, OH),8.14-8.12(m, 2H, ArH),7.25-7.23 (m, 2H, ArH),5.54 (s, 1H, CH), 2.51-2.31 (m,8H,4(CH 2 ), 1.24(s, 6H,2(CH 3 ), 1.11(s,6H,2(CH 3 ); 13 C NMR (125 MHz, CDCl 3  /TMS)  δ C :190.9,189.6, 146.5, 146.1, 127.6, 123.5, 114.9, 46.9, 46.4,33.3, 31.5, 29.5, 27.5.III. RESULT AND DISCUSSIONS The MnO 2 NPs synthesised by hydrothermal method has been characterised as follows. Initially, a Ramanspectrum was recorded. AstrongRamanbandat646cm − 1 ofMnO 2 NPscanbeattributedtothesymmetricstretchingvibration(Mn  –  O)oftheMnO 2 (Fig.1a).The X-ray powder pattern of the MnO 2 NPs showedpeaks at 2θ = 28.75, 37.53 and 41.01 º confirming the presence of  β -MnO 2 NPs[JCPDS# 81-2261] and the crystallinesize of MnO 2 NPswas found to be 40.26 nm(Fig. 1b). TheFESEM imagesshowedthe well-defined nanocrystalsnatureofsynthesisedMnO 2 NPs. The particle sizeofMnO 2 NPswas estimated to be about 100 nm(Fig. 1c).The EDAX analysis confirms the presence of MnO 2 (Fig. 1d).The catalytic behavior of theMnO 2 NPsc atalyst was examined for the synthesis of 2,2’ -phenylmethylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) derivatives. Thus, initially a mixture of benzaldehyde 1a , and5, 5-dimethyl-1,3-cyclohexanedione 2 under solvent and catalyst free conditions for the synthesis of 2,2’ -phenylmethylenebis (3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) (Table I, entry 1). However, the reaction afforded only 2,2’ -phenylmethylenebis (3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) 3a in 40% yield.Interestingly, the useof MnO 2 NPs as heterogeneous catalyst under solvent- free condition afforded 2,2’ -phenylmethylene bis (3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) 3a in 94-96% yield (Table I, entry 4 and5). On the other hand, the reaction with different amounts of MnO 2 NPs catalyst under solvent-free conditions at80°C provided the desired compound 3a in 65% yield (Table 1, entry 2 and 3). When reaction was carried out at100°C the desired compound 3a was obtained in good yield and the results are summarized in Table I.It hasbeen found that 10 mol % of MnO 2 NPs is the optimum amount of catalyst (Table 1, entry 5). Increasing mol %  (IJIRSE) International Journal ofInnovative Research in Science & Engineering  ISSN (Online) 2347-3207  of catalyst beyond 10% did not alter the yield (Table I, entry 6), while reducing the mol % of catalyst decreasedthe yield (Table I, entry 7). Figure 1.(a) Raman spectra; (b) PXRD; (c) FESEM and (d) EDAX of MnO 2 NPsScheme 1TABLE I.O PTIMIZATION OF M N O 2 NP SCATALYST FOR THE ONE - POT CONDENSATION OFDIMEDONE 2 A WITH BENZALDEHYDE 1 A Entry MnO 2 NPs (mol %)Temperature (°C)Time (min)ProductYield a (%) 1-10020 3a 402108020 3a 653158020 3a 6541010010 3a 94 510100203a96 61510020 3a 967510030 3a 75 a Reaction condition: benzaldehyde:5, 5-dimethyl-1,3-cyclohexanedione1:2,at different temperatureEncouraged by the preliminary results and in order to demonstrate the method is general, under the optimizedcondition,we have used variousaryl aldehydes 1a-k were reacted with 2 and the reactions preceded well toaffordbis (3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) 3a-k in excellent yields (TableII).From theexperimental results, it is observed that,the substitution at the 4-position of the aromatic aldehyde had nosignificant effect and aldehydes with either electron-donating group or electron-withdrawing groupdid not alterthe yields of the products significantly. Demonstrating the diversity of the aldehydes, heterocyclic aldehyde suchas 2-thiophene aldehyde 1k afforded the desired product 3k in excellent yield (TableII, entry 11).It should benoted that the present catalyst has advantages over other catalysts in terms ofhigh yield, short reaction time,relative non-toxicity, easy workupand ability to perform reactionsundersolvent free conditions.Recycling of catalyst was achieved for three times without loss of activity.All the compounds were characterized byspectroscopic data (FTIR, 1 HNMRand 13 CNMR).  (IJIRSE) International Journal ofInnovative Research in Science & Engineering  ISSN (Online) 2347-3207  TABLE II.S YNTHESIS OF 1,8-D IOXO - OCTAHYDRO - XANTHENES 5 A - J EntryAr-CHODiketoneTime (min)ProductYield (%) a 1C 6 H 5 , 1a2 15 3a 9823-H 3 C-C 6 H 4 , 1b2 25 3b 9234-H 3 C-C 6 H 4 1c2 20 3c 9243-Cl-C 6 H 4 , 1d2 25 3d 9354-Cl-C 6 H 4 , 1e2 20 3e 9663-Br-C 6 H 4 , 1f 2 20 3f  8874-Br-C 6 H 4 , 1g2 20 3g 9083-NO 2 -C 6 H 4 , 1h2 20 3h 9494-NO 2 -C 6 H 4 , 1i2 15 3i 94104-HO-C 6 H 4 , 1j2 45 3j 92112-Thienyl, 1k2 45 3k 90 The formation of compound 3 can be explained by the mechanism that presented in Scheme2. The reactionsequence is one-pot Knoevenagel condensation, Michael addition and tautomerization.Xanthene derivative 3 wasbelieved to be formed via an initial Knoevenagel condensation of 5,5-dimethyl-1,3-cyclohexanedione 2 withbenzaldehyde 1a to afford intermediate I . Then the active methylene of 5,5-dimethyl-1,3-cyclohexanedione 2 reacts with intermediate I via a conjugate Michael addition to generate the intermediate II , which upontautomerization gives compound 3 . OOOO HOOH Ar O-H 2 OO Ar OOOHMichael addition Ar O OO O Ar O OOH OHHO Ar O 2 Mn 2213III Scheme2.Proposed mechanism for the synthesis 3 In summary, a highly stable and environmentally benign MnO 2 NPscatalystwas prepared and thoroughlycharacterized by Raman, XRD, FESEM and EDAX techniques. The catalytic activity of MnO 2 NPshas beendemonstrated for the synthesis of  2,2’ -arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one)undersolvent free conditions. The catalyst was found to be recyclable without loss of activity. Further work utilizing thecatalysts for other synthetic transformations is in progress in this laboratory.A CKNOWLEDGMENTS AuthorsthankstoUniversity of Madras for providing infrastructure facilities,Director, National Center forNanoscience and Nanotechnology (NCNSNT), University of Madras for Raman, and FE-SEM/EDAXmeasurements and Department of Chemistry, St. Joseph College, Bangalore, for XRD measurements.R EFERENCES[1]K.M. Khan, G.M. Maharvi, M.T.H. Khan, A.J. Shaikh, S. Perveen, S.B. Mild, M.I. Choudhary,Tetraketones: a new class of tyrosinaseinhibitors,Bioorg. Med. Chem., 14 (2006), pp. 344 – 351.[2]G.M. Maharvi, S. Ali, N. Riaz, N. Afza, A. Malik, M. Ashraf, L. Iqbal, M. Lateef,Mild and efficient synthesis of new tetraketones aslipoxygenase inhibitors and antioxidants,J. Enzyme Inhib. Med. Chem., 23 (2008), pp. 62 – 69.[3]O. Sirkecioglu, N. Talinli, A. Akar,Synthesis of 14-alkyl-14H-dibenzo [a,j]xanthenes,J. Chem. Res. (1995), p. 502.[4] T.S. Jin, A.Q. Wang, H. Ma, J.S. Zhang, T.S. Li, “The reaction of aromatic aldehydes and 5,5 -dimethyl-1,3-cyclohexanedione undersolvent- free grinding conditions,” Indian J. Chem. Vol. 45B, 2006, pp. 470-474.[5]T.S. Jin, J. S. Zhang, A.Q. Wang, T.S. Li, “Solid -state condensation reactions between aldehydes and 5,5-dimethyl-1,3- cyclohexanedione by grinding at room temperature,” Synth. Commun. Vol. 35, 2005, pp. 2339-2345.

Zumba Brochure 1

Jul 23, 2017

Scene D

Jul 23, 2017
Search
Tags
Related Search
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks