Novel use of BiOCl as an efficient and selective reagent for cleavage of 2,4-dinitrophenylhydrazones to carbonyl compounds J. Serb. Chem. Soc. 81 (2) 125–131 (2016) UDC 546.872’131:548.512:547.556.9:547.594 JSCS–4832 Original scientific paper 125 Novel use of BiOCl as an efficient and selective reagent for cleavage of 2,4-dinitrophenylhydrazones to carbonyl compounds ABBAS AMINI MANESH* and KHADIJEH AZARIN Department of Chemistry, Payame Noor University, 19395–4697 Tehran, Iran (Received 4 May, revised 14 August, accepted 25 August 2015) Abstract: A novel use of bismuth oxychloride (BiOCl) as an efficient and sel- ective catalyst for the clean cleavage of 2,4-dinitrophenylhydrazones under mild conditions is reported. The reactions proceed very smoothly, and the yields are good to excellent. Over oxidation of aldehydes to carboxylic acid and the formation of by-products were not observed. The catalyst could be recovered and reused for at least four reaction cycles without considerable loss of reactivity. Keywords: bismuth oxychloride; aldehydes; hydrazones; ketones; selective. INTRODUCTION Hydrazones are well-known and synthetically useful derivatives of alde- hydes and ketones. They are usually formed easily from carbonyl compounds and hydrazines in a reversible reaction.1 Hydrazones are important derivatives in car- bonyl chemistry and are used extensively as protecting, activating, and directing groups.2 Regeneration of carbonyl compounds from stable and readily prepared oximes, hydrazones and semicabazones has received considerable attention in recent years.3–6 There are only a few reports available dealing with these reac- tions.7–11 Although some are realized under mild conditions, most of these regenerations are often hazardous or use very toxic, expensive, or not readily available reagents, or reagents which need to be freshly prepared.12–14 Thus, there is still a need to develop new and facile procedures for the regeneration of carbonyl compounds from 2,4-dinitrophenylhydrazones. In continuation of a systematic study and research on oxidation methods,15–19 herein, a new simple and selective method for the conversion of 2,4-dinitrophe- nylhydrazones to their corresponding aldehydes and ketones by the novel use of bismuth oxychloride is reported. * Corresponding author. E-mail: a_aminima@yahoo.com doi: 10.2298/JSC150504071M _________________________________________________________________________________________________________________________ (CC) 2016 SCS. All rights reserved. Available on line at www.shd.org.rs/JSCS/ 126 AMINI MANESH and AZARIN According to a literature search, there is not a great deal of work on the use of BiOCl as an oxidant and hence, this is the first report on the use of BiOCl as a reagent for the regeneration of the carbonyl group from 2,4-dinitrophenylhydra- zones that act as a catalyst. The simple reaction of different hydrazones by BiOCl in acetonitrile under reflux conditions gave the corresponding carbonyl compounds in good yields (Scheme 1). Scheme 1. Cleavage of hydrazones by BiOCl. EXPERIMENTAL Chemicals and apparatus Chemicals were purchased from Merck, Fluka and Aldrich chemical companies. The solvents were used as received. All products were known and identified by comparison of their m.p., b.p., IR and NMR data with those reported for the authentic samples. All yields refer to the isolated products. The progress of the reaction was monitored by TLC. The IR and 1H-NMR spectra were recorded on a Shimadzu infrared spectrophotometer FT-IR, model IR Prestige 21 (KBr pellets), and a 90 MHz Jeol FT-NMR spectrometer, respectively. The 1H- -NMR chemical shifts were measured relative to TMS. BiOCl was prepared according to previously reported procedure.20 The 2,4-dinitrophe- nylhydrazones were prepared by a standard procedure.21 General procedure for the cleavage of hydrazones by bismuth oxychloride: A solution of the hydrazone (1 mmol) in acetonitrile (10 mL) was refluxed for 10 min. Then BiOCl (1 mmol) was added to the solution and the mixture was refluxed for the appropriate time, as indicated in Table I. After completion of the reaction (TLC monitored), the reaction mixture was cooled to room temperature and H2O (1 mmol) was added and the mixture stirred for 10 min. Then the solvent was evaporated and CHCl3 or THF was added. After stirring the mixture for 10 min, the solid residue was filtered off and washed with CHCl3 or THF (10 mL). Evaporation of the solvent gave the pure carbonyl products in excellent yields. The products were characterized by their physical constants and IR and NMR spectra, which were compared with those of authentic samples.22-31 Recovery of the BiOCl The residue on the filter paper was separated, HCl was added, the pH of the aqueous solution adjusted to 3 and the mixture stirred until the BiOCl was dissolved. The mixture was filtered (2,4-dinitrophenylhydrazine was separated as residue on the filter paper), Na2CO3 (5 % aqueous solution) was added to the filtrate and the pH of the aqueous solution was adjusted to 8–9. After stirring at room temperature for 30 min, the resulting precipitate was filtrated and washed with deionized water several times. Finally, the white powders of BiOCl were obtained by drying the precipitate at 80 °C for 5 h. _________________________________________________________________________________________________________________________ (CC) 2016 SCS. All rights reserved. Available on line at www.shd.org.rs/JSCS/ BiOCl: EFFICIENT REAGENT FOR CLEAVAGE OF HYDRAZONES 127 RESULT AND DISCUSSION The results illustrated in Table I indicate that the reaction was successful for a variety of aliphatic and aromatic 2,4-dinitrophenylhydrazones (Scheme 1). TABLE I. Conversion of 2,4-dinitrophenylhydrazones to the corresponding carbonyl com- pounds by BiOCl; reaction conditions: hydrazine, 1 mmol, BiOCl, 1 mmol, H2O, 1 mmol, CH3CN; under reflux Yielda, % Time, h Product Reactant No. 8522 2:20 NO2 O2N NHNCH 1 8222 2:15 2 7822 2 3 9222 3:15 4 8923 2:10 H3C O CH3 5 9022 1 6 9224,25 2:35 7 8126 1:15 8 8827 1:20 9 _________________________________________________________________________________________________________________________ (CC) 2016 SCS. All rights reserved. Available on line at www.shd.org.rs/JSCS/ 128 AMINI MANESH and AZARIN TABLE I. Continued Yielda, % Time, h Product Reactant No. 7028 3:20 10 8529 4 11 8530,31 4:25 12 6027 2:50 13 aIsolated yields All these carbonyl derivatives were converted back to their corresponding aldehydes and ketones in acetonitrile as the optimal solvent among the tested solvents, including: methanol, ethanol, chloroform, diethyl ether and acetonitrile, taking benzophenone 2,4-dinitrophenylhydrazone as a representative example (Table II). TABLE II. Optimization of the solvent Entry Solvent Time, h T / °C Yield, % 1 MeOH 1 64 65 2 EtOH 1 78 70 3 CHCl3 1 62 60 4 (C2H5)2O 1 40 10 5 CH3CN 1 80 90 Moreover, the reactions were run with different amounts of BiOCl. On anal- yzing the different results, it was concluded that the best reaction conditions were 1 mmol of oxidant BiOCl in CH3CN media under reflux conditions. A sterically hindered ketone hydrazine was successfully cleaved to the cor- responding ketone in good yield. The hydrazones of aldehyde were converted into the corresponding alde- hydes and no acid, due to oxidation of the regenerated aldehyde, was formed (entries 1–3 and 10–13, Scheme 2). Based on the above results, a plausible reaction mechanism is shown in Scheme 3. _________________________________________________________________________________________________________________________ (CC) 2016 SCS. All rights reserved. Available on line at www.shd.org.rs/JSCS/ BiOCl: EFFICIENT REAGENT FOR CLEAVAGE OF HYDRAZONES 129 85 % 0 % Scheme 2. Selective cleavage of hydrazone. Scheme 3. Proposed mechanism for the cleavage of hydrazones. Catalyst reuse and stability An important advantage of BiOCl in these reactions is its facile recovery from the reaction mixture and reusability. The catalyst reuse and stability was checked using benzophenone 2,4-dinitrophenylhydrazone as a model substrate. The recovery of catalyst was very easy. The products are soluble in CHCl3 or THF, while the catalyst remains insoluble. The catalyst was separated from the reaction mixture after each experiment by simple filtration. As shown in Table III, the BiOCl catalyst was reusable four times and its activity did not show any significant decrease. _________________________________________________________________________________________________________________________ (CC) 2016 SCS. All rights reserved. Available on line at www.shd.org.rs/JSCS/ 130 AMINI MANESH and AZARIN TABLE III. Reusability of BiOCl catalyst in the hydrolysis of benzophenone 2,4-dinitro- phenylhydrazone Run No. Time, h Yielda, % 1 1 90 2 1:30 83 3 1:45 75 4 2 70 aIsolated yield CONCLUSIONS In this study, oxidation of the aldehydes to carboxylic acids and the form- ation of by products were not observed. Moreover, the synthesis of the catalyst (bismuth oxychloride) is very simple and the required starting materials are commercially available and cheap. The stability and activity of the catalyst are other advantages of this reagent. The catalyst could be recovered and reused for at least four reaction cycles without considerable loss of reactivity. The striking features of the proposed method are availability, the cost of reagent, easy preparation of the catalyst, easy and clean work-up procedure (most do not require chromatography), absence of the formation of oxidation products due to the high selectivity and mild nature of the catalyst, high yields and recovery and reusability of the catalyst. Overall, this simple, clean, selective and efficient procedure for the hydro- lysis of various hydrazones to carbonyl compounds on a medium to large scale could be recommended. Acknowledgement. The authors acknowledge the support of this work by the Hamedan Payame Noor University. И З В О Д НОВА ПРИМЕНА BiOCl КАО ЕФИКАСНОГ И СЕЛЕКТИВНОГ РЕАГЕНСА ЗА РАСКИДАЊЕ 2,4-ДИНИТРОФЕНИЛХИДРАЗОНА ДО КАРБОНИЛНИХ ЈЕДИЊЕЊА ABBAS AMINI MANESH и KHADIJEH AZARIN Department of Chemistry, Payame Noor University, 19395–4697 Tehran, Iran Приказана је нова примена бизмут-оксихлорида као ефикасног и селективног реагенса за раскидање 2,4-динитрофенилхидразона под благим реакционим условима. Реакције се одигравају без потешкоћа у добром до одличном приносу. Није уочена окси- дација алдехида до карбоксилних киселина или формирање других споредних произ- вода. Реагенс се може изоловати из реакционе смеше, и поновно користити у бар четири наредна реакциона циклуса без значајнијег губитка реактивности. (Примљено 4. маја, ревидирано 14. августа, прихваћено 25. августа 2015) REFERENCES 1. D. Y. Jung, Y. H. Kim, Synlett 20 (2005) 3019 2. D. Enders, in Asymmetric Synthesis, Vol. 3, J. D. Morrison, Ed., Academic Press, Orlando, FL, 1984, pp. 275–339, and literature cited therein _________________________________________________________________________________________________________________________ (CC) 2016 SCS. All rights reserved. Available on line at www.shd.org.rs/JSCS/ BiOCl: EFFICIENT REAGENT FOR CLEAVAGE OF HYDRAZONES 131 3. J. M. Khurana, A. Ray, P. K. Sahoo, Bull. Chem. Soc. Jpn. 67 (1994) 1091 4. F. Shirini, M. A. Zolfigol, M. R. Azadbar, Synth. Commun. 32 (2002) 315 5. F. Shirini, M. R. Azadbar, Synth. Commun. 31 (2001) 3775 6. F. Shirini, M. Mamaghani, F. Parsa, I. Mohammadpoor-Baltork, Bull. Korean Chem. Soc. 23 (2002) 1683 7. M. Carmeli, S. Rozen, Tetrahedron Lett. 47 (2006) 763 8. D. H. R. Barton, D. J. Lester, J. Chem. Soc. Perkin Trans. 1 (1980) 1212 9. B. C. Ranu, D. C. Sarkar, J. Org. Chem. 53 (1988) 878 10. P. Laszlo, E. Polla, Synthesis (1985) 439 11. S. Narayanan, V. S. Srinivasan, J. Chem. Soc. Perkin. Trans. 2 (1986) 1557 12. T. W. Greene, P. G. M. Wuts, Protective Groups in Organic Synthesis, Wiley, New York, 1991 13. G. W. Kabalka, R. D. Pace, P. P. Wadgaonkaf, Synth. Commun. 20 (1990) 2453 14. B. P. Bandgar, S. I. Shaikh, S. Iyyer, Synth. Commun. 26 (1996) 1163 15. A. Khazaei, A. Amini Manesh, A. Rostami, J. Chem. Res. 6 (2005) 391 16. A. Khazaei, A. Amini Manesh, J. Braz. Chem. Soc. 16 (2005) 874 17. A. Khazaei, A. Amini Manesh, A. Rostami, J. Chem. Res. 10 (2004) 695 18. A. Khazaei, A. Amini Manesh, A. Rostami, Phosphorus, Sulfur Silicon Relat. Elem. 179 (2004) 2483 19. A. Khazaei, A. Amini Manesh, Synthesis 12 (2005) 1929. 20. S. Zhu-qing, W. Yan, F. Cai-mei, W. Yun-fang, D. Guang-yue, Trans. Nonferrous Met. Soc. China 21 (2011) 2254 21. R. L. Shriner, R. C. Fuson, D. Y. Curtin, T. C. Morrill, The Systematic Identification of Organic Compounds; 6th ed., Wiley, New York, 1980 22. G. Sarifuddin, A. Rajakumar, RSC Adv. 2 (2012) 7781 23. A. Kaliyamoorthy, P. Kandikere Ramaiah, Tetrahedron 67 (2011) 8544 24. C. J. Pouchert, The Aldrich Library of Infrared Spectra, ed. 3, Aldrich Chem. Co., Milwaukee, WI, 1981, p. 240, D 25. C. J. Pouchert, The Aldrich Library of NMR Spectra, ed. 2, Aldrich Chem. Co., Milwaukee, WI, 1983, Vol. 1, p. 369, C 26. W. Shang, M. Hengchang, L. Ziqiang, Tetrahedron 66 (2010) 8641 27. R. Laxmidhar, N. Pinku, P. Tharmalingam, Adv. Synth. Catal. 349 (2007) 846 28. Z. Guofu, W. Xin, W. Yong, H. Xingwang, L. Yuxin, Z. Lebin, D. Chengrong, C. Xiaoji, RSC Adv. 3 (2013) 22918 29. L. Yang, Z. Rong, H. Cheng, D. Dongbin, D. Chunying, Chem. Commun. 46 (2010) 746 30. C. J. Pouchert, The Aldrich Library of Infrared Spectra, ed. 3, Aldrich Chem. Co., Milwaukee, WI, 1981 p. 928, A 31. C. J. Pouchert, The Aldrich Library of NMR Spectra, ed. 2, Aldrich Chem. Co., Milwaukee, WI, 1983, Vol. 2, p. 132, C. _________________________________________________________________________________________________________________________ (CC) 2016 SCS. All rights reserved. Available on line at www.shd.org.rs/JSCS/ << /ASCII85EncodePages false /AllowTransparency false /AutoPositionEPSFiles true /AutoRotatePages /None /Binding /Left /CalGrayProfile (Dot Gain 20%) /CalRGBProfile (sRGB IEC61966-2.1) /CalCMYKProfile (U.S. Web Coated \050SWOP\051 v2) /sRGBProfile (sRGB IEC61966-2.1) /CannotEmbedFontPolicy /Error /CompatibilityLevel 1.4 /CompressObjects /Tags /CompressPages true /ConvertImagesToIndexed true /PassThroughJPEGImages true /CreateJobTicket false /DefaultRenderingIntent /Default /DetectBlends true /DetectCurves 0.0000 /ColorConversionStrategy /CMYK /DoThumbnails false /EmbedAllFonts true /EmbedOpenType false /ParseICCProfilesInComments true /EmbedJobOptions true /DSCReportingLevel 0 /EmitDSCWarnings false /EndPage -1 /ImageMemory 1048576 /LockDistillerParams false /MaxSubsetPct 100 /Optimize true /OPM 1 /ParseDSCComments true /ParseDSCCommentsForDocInfo true /PreserveCopyPage true /PreserveDICMYKValues true /PreserveEPSInfo true /PreserveFlatness true /PreserveHalftoneInfo false /PreserveOPIComments true /PreserveOverprintSettings true /StartPage 1 /SubsetFonts true /TransferFunctionInfo /Apply /UCRandBGInfo /Preserve /UsePrologue false /ColorSettingsFile () /AlwaysEmbed [ true ] /NeverEmbed [ true ] /AntiAliasColorImages false /CropColorImages true /ColorImageMinResolution 300 /ColorImageMinResolutionPolicy /OK /DownsampleColorImages true /ColorImageDownsampleType /Bicubic /ColorImageResolution 300 /ColorImageDepth -1 /ColorImageMinDownsampleDepth 1 /ColorImageDownsampleThreshold 1.50000 /EncodeColorImages true /ColorImageFilter /DCTEncode /AutoFilterColorImages true /ColorImageAutoFilterStrategy /JPEG /ColorACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /ColorImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000ColorACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000ColorImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasGrayImages false /CropGrayImages true /GrayImageMinResolution 300 /GrayImageMinResolutionPolicy /OK /DownsampleGrayImages true /GrayImageDownsampleType /Bicubic /GrayImageResolution 300 /GrayImageDepth -1 /GrayImageMinDownsampleDepth 2 /GrayImageDownsampleThreshold 1.50000 /EncodeGrayImages true /GrayImageFilter /DCTEncode /AutoFilterGrayImages true /GrayImageAutoFilterStrategy /JPEG /GrayACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /GrayImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000GrayACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000GrayImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasMonoImages false /CropMonoImages true /MonoImageMinResolution 1200 /MonoImageMinResolutionPolicy /OK /DownsampleMonoImages true /MonoImageDownsampleType /Bicubic /MonoImageResolution 1200 /MonoImageDepth -1 /MonoImageDownsampleThreshold 1.50000 /EncodeMonoImages true /MonoImageFilter /CCITTFaxEncode /MonoImageDict << /K -1 >> /AllowPSXObjects false /CheckCompliance [ /None ] /PDFX1aCheck false /PDFX3Check false /PDFXCompliantPDFOnly false /PDFXNoTrimBoxError true /PDFXTrimBoxToMediaBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXSetBleedBoxToMediaBox true /PDFXBleedBoxToTrimBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXOutputIntentProfile () /PDFXOutputConditionIdentifier () /PDFXOutputCondition () /PDFXRegistryName () /PDFXTrapped /False /CreateJDFFile false /Description << /ARA /BGR /CHS /CHT /CZE /DAN /DEU /ESP /ETI /FRA /GRE /HEB /HRV (Za stvaranje Adobe PDF dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. Stvoreni PDF dokumenti mogu se otvoriti Acrobat i Adobe Reader 5.0 i kasnijim verzijama.) /HUN /ITA /JPN /KOR /LTH /LVI /NLD (Gebruik deze instellingen om Adobe PDF-documenten te maken die zijn geoptimaliseerd voor prepress-afdrukken van hoge kwaliteit. De gemaakte PDF-documenten kunnen worden geopend met Acrobat en Adobe Reader 5.0 en hoger.) /NOR /POL /PTB /RUM /RUS /SKY /SLV /SUO /SVE /TUR /UKR /ENU (Use these settings to create Adobe PDF documents best suited for high-quality prepress printing. Created PDF documents can be opened with Acrobat and Adobe Reader 5.0 and later.) >> /Namespace [ (Adobe) (Common) (1.0) ] /OtherNamespaces [ << /AsReaderSpreads false /CropImagesToFrames true /ErrorControl /WarnAndContinue /FlattenerIgnoreSpreadOverrides false /IncludeGuidesGrids false /IncludeNonPrinting false /IncludeSlug false /Namespace [ (Adobe) (InDesign) (4.0) ] /OmitPlacedBitmaps false /OmitPlacedEPS false /OmitPlacedPDF false /SimulateOverprint /Legacy >> << /AddBleedMarks false /AddColorBars false /AddCropMarks false /AddPageInfo false /AddRegMarks false /ConvertColors /ConvertToCMYK /DestinationProfileName () /DestinationProfileSelector /DocumentCMYK /Downsample16BitImages true /FlattenerPreset << /PresetSelector /MediumResolution >> /FormElements false /GenerateStructure false /IncludeBookmarks false /IncludeHyperlinks false /IncludeInteractive false /IncludeLayers false /IncludeProfiles false /MultimediaHandling /UseObjectSettings /Namespace [ (Adobe) (CreativeSuite) (2.0) ] /PDFXOutputIntentProfileSelector /DocumentCMYK /PreserveEditing true /UntaggedCMYKHandling /LeaveUntagged /UntaggedRGBHandling /UseDocumentProfile /UseDocumentBleed false >> ] >> setdistillerparams << /HWResolution [2400 2400] /PageSize [612.000 792.000] >> setpagedevice