Tin sulfide nanoparticles supported on activated carbon as an efficient and reusable Lewis acid catalyst for three-component one-pot synthesis of 4H-pyrano[2,3-c]pyrazole derivatives

Article abstract of DOI:10.1016/S1872-2067(14)60284-9

Tin sulfide nanoparticles (SnS-NPs) were prepared in aqueous solution at room temperature on the surface of activated carbon (AC) and were investigated using field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-r

Full text of DOI:10.1016/S1872-2067(14)60284-9

ChineseꢀJournalꢀofꢀCatalysisꢀ36ꢀ(2015)ꢀ626–633
ꢀ
ꢀ ꢀ ꢀ
ꢀ ꢀ ꢀ ꢀ
a v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m
ꢀ
j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / c h n j c
ꢀ
ꢀ
Article
Tinꢀsulfideꢀnanoparticlesꢀsupportedꢀonꢀactivatedꢀcarbonꢀasꢀanꢀ ꢀ
efficientꢀandꢀreusableꢀLewisꢀacidꢀcatalystꢀforꢀthree‐componentꢀ
one‐potꢀsynthesisꢀofꢀ4H‐pyrano[2,3‐c]pyrazoleꢀderivativesꢀ ꢀ
ꢀa,
ꢀb,#
ꢀa
ꢀc
NasirꢀIravani *,ꢀMosadeghꢀKeshavarz ,ꢀHosseinꢀAliꢀShojaeianꢀKish ,ꢀRasoolꢀParandvar
ꢀ
aꢀDepartmentꢀofꢀChemistry,ꢀFacultyꢀofꢀScience,ꢀGachsaranꢀBranch,ꢀIslamicꢀAzadꢀUniversity,ꢀGachsaran,ꢀIranꢀ
bꢀDepartmentꢀofꢀGasꢀandꢀPetroleum,ꢀYasoujꢀUniversity,ꢀGachsaran,ꢀIranꢀ ꢀ
cꢀYoungꢀandꢀReasearcersꢀElite,ꢀGachsaranꢀBranch,ꢀIslamicꢀAzadꢀUniversity,ꢀGachsaran,ꢀIranꢀ
A R T I C L E ꢀ I N F O ꢀ
A B S T R A C T ꢀ
Articleꢀhistory:ꢀ
Tinꢀsulfideꢀnanoparticlesꢀ(SnS‐NPs)ꢀwereꢀpreparedꢀinꢀaqueousꢀsolutionꢀatꢀroomꢀtemperatureꢀonꢀtheꢀ
surfaceꢀofꢀactivatedꢀcarbonꢀ(AC)ꢀandꢀwereꢀinvestigatedꢀusingꢀfield‐emissionꢀscanningꢀelectronꢀmi‐
croscopyꢀ(FE‐SEM),ꢀtransmissionꢀelectronꢀmicroscopyꢀ(TEM),ꢀX‐rayꢀdiffraction,ꢀreflectiveꢀultravio‐
let‐visibleꢀ spectrophotometry,ꢀ andꢀ spectrofluorimetry.ꢀ Calculationsꢀ basedꢀ onꢀ theꢀ SEMꢀ andꢀ TEMꢀ
imagesꢀshowedꢀthatꢀtheꢀsizesꢀofꢀtheꢀSnS‐NPsꢀimmobilizedꢀonꢀtheꢀACꢀwereꢀ30–70ꢀnm.ꢀTheꢀpreparedꢀ
nanocompositeꢀwasꢀusedꢀasꢀaꢀheterogeneousꢀLewisꢀacidꢀcatalystꢀforꢀtheꢀthree‐componentsꢀone‐potꢀ
synthesisꢀofꢀ4H‐pyrano[2,3‐c]pyrazoleꢀderivativesꢀinꢀethanolꢀatꢀ80ꢀ°C.ꢀTheꢀreactionsꢀwereꢀefficientlyꢀ
performedꢀinꢀtheꢀpresenceꢀofꢀtheꢀpreparedꢀcatalystꢀinꢀshortꢀreactionꢀtimes,ꢀandꢀgaveꢀtheꢀdesiredꢀ
productsꢀinꢀhighꢀyields.ꢀThisꢀcatalystꢀcanꢀbeꢀeasilyꢀrecoveredꢀbyꢀsimpleꢀfiltrationꢀandꢀrecycledꢀupꢀtoꢀ
eightꢀconsecutiveꢀtimesꢀwithoutꢀsignificantꢀlossꢀofꢀitsꢀefficiency.ꢀ
Receivedꢀ13ꢀNovemberꢀ2014ꢀ
Acceptedꢀ15ꢀDecemberꢀ2014ꢀ
Publishedꢀ20ꢀAprilꢀ2015ꢀ
Keywords:ꢀ
Tinꢀsulfideꢀnanoparticleꢀ
Nanocompositeꢀ
Lewisꢀacidꢀcatalystꢀ
Heterogeneousꢀcatalystꢀ
©ꢀ2015,ꢀDalianꢀInstituteꢀofꢀChemicalꢀPhysics,ꢀChineseꢀAcademyꢀofꢀSciences.
4H‐pyrano[2,3‐c]pyrazoleꢀ
PublishedꢀbyꢀElsevierꢀB.V.ꢀAllꢀrightsꢀreserved.
Multicomponentꢀreaction
1
.ꢀ ꢀ Introductionꢀ
includingꢀ electrodeꢀ depositionꢀ [3],ꢀ solvothermalꢀ routesꢀ [4,5],ꢀ
thermalꢀdecompositionꢀ[6],ꢀandꢀchemicalꢀreductionꢀ[7].ꢀTheseꢀ
studiesꢀhaveꢀledꢀtoꢀtheꢀsuccessfulꢀsynthesisꢀofꢀmanyꢀnanocrys‐
tals,ꢀ includingꢀ metalsꢀ [8,9],ꢀ oxidesꢀ [10],ꢀ andꢀ sulfidesꢀ [11,12],ꢀ
andꢀtheseꢀhaveꢀalreadyꢀbeenꢀusedꢀasꢀoptoelectronicꢀmaterialsꢀ
inꢀsensors,ꢀlaserꢀmaterials,ꢀsolarꢀcells,ꢀandꢀotherꢀdevices.ꢀ ꢀ
Crystallineꢀandꢀpartiallyꢀcrystallineꢀnanosulfidesꢀhaveꢀbeenꢀ
extensivelyꢀ studied,ꢀ becauseꢀ theyꢀ haveꢀ numerousꢀ potentialꢀ
applicationsꢀasꢀcatalystsꢀforꢀuseꢀinꢀcoalꢀliquefaction,ꢀsolidꢀlub‐
ricants,ꢀrechargeableꢀbatteries,ꢀsolarꢀcells,ꢀandꢀcoatingsꢀforꢀmi‐
crowaveꢀshieldsꢀ[13–16].ꢀInꢀparticular,ꢀtinꢀsulfideꢀ(SnS),ꢀwhichꢀ
hasꢀaꢀlayeredꢀstructure,ꢀisꢀanꢀimportantꢀsemiconductor,ꢀwithꢀanꢀ
energyꢀbandꢀgapꢀofꢀaboutꢀ1.08ꢀeVꢀ[17];ꢀitꢀhasꢀpotentialꢀapplica‐
tionsꢀinꢀsolarꢀcellsꢀ[18,19]ꢀandꢀphotovoltaicꢀdevicesꢀ[20].ꢀ ꢀ
Nanomaterialsꢀ haveꢀ beenꢀ extensivelyꢀ studiedꢀ becauseꢀ ofꢀ
theirꢀ specificꢀ physicalꢀ andꢀ chemicalꢀ propertiesꢀ andꢀ potentialꢀ
applicationsꢀinꢀdiverseꢀareasꢀ[1].ꢀTheseꢀpropertiesꢀandꢀpoten‐
tialꢀ applicationsꢀ haveꢀ stimulatedꢀ researchꢀ intoꢀ newꢀ methodsꢀ
forꢀsynthesizingꢀtheseꢀmaterials.ꢀ
Recently,ꢀnanocatalysisꢀhasꢀbeenꢀintroducedꢀasꢀaꢀsustainableꢀ
andꢀcompetitiveꢀalternativeꢀtoꢀconventionalꢀcatalysis;ꢀnanopar‐
ticlesꢀ haveꢀ highꢀ surface‐to‐volumeꢀ ratios,ꢀ andꢀ thisꢀ increasesꢀ
theirꢀactivitiesꢀandꢀselectivities,ꢀwhileꢀconservingꢀtheꢀbasicꢀfea‐
turesꢀofꢀaꢀheterogeneousꢀcatalystꢀ[2].ꢀ ꢀ
Inꢀrecentꢀyears,ꢀmuchꢀeffortꢀhasꢀbeenꢀdevotedꢀtoꢀtheꢀprepa‐
rationꢀofꢀvariousꢀnanocrystalsꢀusingꢀaꢀwideꢀvarietyꢀofꢀmethods,ꢀ
*
ꢀ
ꢀCorrespondingꢀauthor.ꢀTel:ꢀ+98‐743‐2334751;ꢀFax:ꢀ+98‐743‐2332003;ꢀE‐mail:ꢀiravani.nasir@yahoo.com,ꢀiravaninasir56@gmail.comꢀ
Correspondingꢀauthor.ꢀE‐mail:ꢀchem.mosadegh@gmail.comꢀ
#
DOI:ꢀ10.1016/S1872‐2067(14)60284‐9ꢀ|ꢀhttp://www.sciencedirect.com/science/journal/18722067ꢀ|ꢀChin.ꢀJ.ꢀCatal.,ꢀVol.ꢀ36,ꢀNo.ꢀ4,ꢀAprilꢀ2015ꢀ ꢀ ꢀ

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NasirꢀIravaniꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ36ꢀ(2015)ꢀ626–633ꢀ
627ꢀ
Pyrano[2,3‐c]pyrazolesꢀareꢀimportantꢀinꢀmedicinalꢀchemis‐
Inꢀtheꢀnextꢀstep,ꢀtheꢀfreshlyꢀpreparedꢀSnS‐NPꢀsolutionꢀ(500ꢀ
mL,ꢀ1ꢀmmol/L)ꢀwasꢀmixedꢀwithꢀACꢀ(10ꢀg)ꢀinꢀaꢀ1000‐mLꢀflaskꢀ
underꢀmagneticꢀstirringꢀforꢀupꢀtoꢀ12ꢀh,ꢀresultingꢀinꢀdepositionꢀ
ofꢀSnS‐NPsꢀonꢀtheꢀAC.ꢀTheꢀAC‐supportedꢀSnS‐NPsꢀwereꢀfilteredꢀ
andꢀ thoroughlyꢀ washedꢀ withꢀ doublyꢀ distilledꢀ water.ꢀ Theꢀ
SnS‐NPsꢀinꢀtheꢀinitialꢀundilutedꢀfiltrateꢀsolutionꢀwereꢀanalyzedꢀ
usingꢀUV‐visꢀspectrophotometry.ꢀTheꢀSnS‐NPs@ACꢀsampleꢀwasꢀ
driedꢀatꢀ110ꢀ°Cꢀinꢀanꢀovenꢀforꢀ10ꢀh.ꢀAꢀmortarꢀwasꢀusedꢀtoꢀho‐
mogeneouslyꢀ grindꢀ theꢀ SnS‐NPs@ACꢀ powders.ꢀ Theꢀ
SnS‐NPs@ACꢀsamplesꢀwereꢀstoredꢀinꢀairꢀatꢀroomꢀtemperatureꢀ
andꢀusedꢀforꢀfurtherꢀcharacterization.ꢀ
tryꢀ asꢀ precursorsꢀ toꢀ potentialꢀ drugs,ꢀ andꢀ theyꢀ showꢀ aꢀ wideꢀ
rangeꢀ ofꢀ biologicalꢀ activitiesꢀ [21–23].ꢀ Theꢀ developmentꢀ andꢀ
improvementꢀofꢀsyntheticꢀapproachesꢀinꢀthisꢀfieldꢀusingꢀeasilyꢀ
accessibleꢀandꢀbenignꢀcatalystsꢀareꢀthereforeꢀimportant.ꢀTheseꢀ
compoundsꢀwereꢀfirstꢀsynthesizedꢀbyꢀOttoꢀinꢀ1974ꢀbyꢀaddingꢀ
malononitrileꢀ toꢀ 4‐arylidene‐3‐methyl‐2‐pyrazolin‐5‐oneꢀ [24].ꢀ
Severalꢀmethodsꢀhaveꢀbeenꢀreportedꢀforꢀtheꢀpreparationꢀofꢀthisꢀ
classꢀofꢀcompoundsꢀ[25–43].ꢀHowever,ꢀsomeꢀofꢀtheseꢀmethodsꢀ
sufferꢀfromꢀdrawbacksꢀsuchꢀasꢀlowꢀyields,ꢀharshꢀreactionꢀcon‐
ditions,ꢀ prolongedꢀ reactionꢀ times,ꢀ andꢀ theꢀ useꢀ ofꢀ hazardousꢀ
and/orꢀcostlyꢀcatalystsꢀandꢀsolvents.ꢀTheꢀdevelopmentꢀofꢀenvi‐
ronmentallyꢀfriendlyꢀapproachesꢀisꢀthereforeꢀstillꢀneeded.ꢀRe‐
cently,ꢀversatileꢀheterogeneousꢀcatalystsꢀproducedꢀbyꢀimmobi‐
lizationꢀofꢀnanoparticlesꢀonꢀsolidꢀsupportsꢀhaveꢀprovidedꢀaꢀnewꢀ
andꢀ environmentallyꢀ benignꢀ approachꢀ toꢀ syntheticꢀ organicꢀ
chemistryꢀ [34,43–46].ꢀ Becauseꢀ ofꢀ theꢀ importanceꢀ ofꢀ pyra‐
no[2,3‐c]pyrazoles,ꢀandꢀasꢀaꢀpartꢀofꢀourꢀcurrentꢀstudiesꢀonꢀtheꢀ
synthesisꢀofꢀheterocyclicꢀcompoundsꢀ[47–53],ꢀinꢀthisꢀpaper,ꢀweꢀ
reportꢀtheꢀone‐potꢀthree‐componentꢀsynthesisꢀofꢀhighlyꢀfunc‐
tionalizedꢀ 4H‐pyrano[2,3‐c]pyrazolesꢀ 2a–2sꢀ byꢀ reactionsꢀ be‐
2.2.ꢀ ꢀ Characterizationꢀ ꢀ
Theꢀ SnS‐NPs@ACꢀ morphologyꢀ wasꢀ examinedꢀ usingꢀ
field‐emissionꢀscanningꢀelectronꢀmicroscopyꢀ(FE‐SEM;ꢀHitachiꢀ
S‐4160)ꢀunderꢀanꢀacceleratingꢀvoltageꢀofꢀ15ꢀkV.ꢀPowderꢀX‐rayꢀ
diffractionꢀ(XRD)ꢀpatternsꢀofꢀtheꢀsamplesꢀwereꢀobtainedꢀusingꢀ
anꢀ automatedꢀ Philipsꢀ X’Pertꢀ X‐rayꢀ diffractometerꢀ withꢀ Cuꢀ K
α
ꢀ
radiationꢀ(40ꢀkVꢀandꢀ30ꢀmA)ꢀatꢀ2θꢀvaluesꢀofꢀ10°–70°.ꢀAbsorp‐
tionꢀ measurementsꢀ andꢀ reflectiveꢀ ultraviolet‐visibleꢀ (UV‐vis)ꢀ
absorptionꢀ spectroscopyꢀ wereꢀ performedꢀwithꢀaꢀPerkinElmerꢀ
Lambdaꢀ25ꢀspectrophotometer,ꢀusingꢀaꢀquartzꢀcellꢀwithꢀanꢀop‐
ticalꢀpathꢀofꢀ1ꢀcm.ꢀTheꢀopticalꢀpropertiesꢀofꢀtheꢀSnS‐NPsꢀwereꢀ
investigatedꢀ basedꢀ onꢀ photoluminescenceꢀ measurementsꢀ atꢀ
roomꢀtemperature,ꢀusingꢀaꢀCaryꢀEclipseꢀspectrofluorometer.ꢀ ꢀ
Fourier‐transformꢀ infraredꢀ (FT‐IR)ꢀ spectraꢀ wereꢀ recordedꢀ
usingꢀ aꢀ BOMEMMB‐Seriesꢀ 1998ꢀ FT‐IRꢀ spectrometerꢀ orꢀ aꢀ
tweenꢀ aldehydesꢀ 1,ꢀ malononitrile,ꢀ andꢀ 3‐methyl‐1‐phenyl‐2‐
ꢀ
pyrazolin‐5‐oneꢀ inꢀ ethanolꢀ atꢀ 80ꢀ °C,ꢀ catalyzedꢀ byꢀ aꢀ new,ꢀ effi‐
cient,ꢀandꢀreusableꢀheterogeneousꢀcatalyst,ꢀnamelyꢀSnSꢀnano‐
particlesꢀ immobilizedꢀ onꢀ activatedꢀ carbonꢀ (SnS‐NPs@AC;ꢀ
Schemeꢀ1).ꢀ
2
.ꢀ ꢀ Experimentalꢀ
1
13
BrukerꢀFT‐IRꢀspectrometer.ꢀ Hꢀandꢀ Cꢀnuclearꢀmagneticꢀreso‐
nanceꢀ(NMR)ꢀspectraꢀwereꢀrecordedꢀusingꢀaꢀBrukerꢀDRX‐400ꢀ
Allꢀ theꢀ startingꢀ materialsꢀ wereꢀ obtainedꢀ fromꢀ Flukaꢀ andꢀ
wereꢀusedꢀwithoutꢀfurtherꢀpurification.ꢀ
AVANCꢀinstrumentꢀinꢀDMSO‐d
6
ꢀorꢀCDCl ꢀatꢀ400ꢀandꢀ100ꢀMHz,ꢀ
3
respectivelyꢀ(resultsꢀareꢀreportedꢀasꢀꢀinꢀpartsꢀperꢀmillion,ꢀwithꢀ
couplingꢀ constants,ꢀ J,ꢀ inꢀ hertz),ꢀ withꢀ tetramethylsilaneꢀ asꢀ anꢀ
internalꢀ standard.ꢀ Meltingꢀ pointsꢀ wereꢀ determinedꢀ usingꢀ anꢀ
SMP1ꢀmelting‐pointꢀapparatusꢀinꢀopenꢀcapillaryꢀtubes,ꢀandꢀareꢀ
uncorrected.ꢀAllꢀtheꢀ4H‐pyrano[2,3‐c]pyrazoleꢀderivativesꢀwereꢀ
preparedꢀusingꢀourꢀprocedure.ꢀTheꢀproductsꢀwereꢀidentifiedꢀbyꢀ
comparisonꢀ ofꢀ theirꢀ spectroscopicꢀ ( Hꢀ andꢀ 13Cꢀ NMR,ꢀ andꢀ IR),ꢀ
thin‐layerꢀchromatographyꢀ(TLC),ꢀandꢀphysicalꢀdataꢀwithꢀthoseꢀ
reportedꢀinꢀtheꢀliteratureꢀ[25–42];ꢀtheꢀdataꢀwereꢀinꢀagreementꢀ
withꢀtheꢀproposedꢀstructures.ꢀAllꢀyieldsꢀreferꢀtoꢀisolatedꢀprod‐
ucts.ꢀ
2
.1.ꢀ ꢀ PreparationꢀofꢀSnS‐NPs@ACꢀ
TheꢀSnS‐NPs@ACꢀsamplesꢀwereꢀpreparedꢀinꢀaqueousꢀsolu‐
tionꢀ atꢀ roomꢀ temperature.ꢀ Inꢀ aꢀ typicalꢀ procedure,ꢀ SnCl
2 2
·2H Oꢀ
(10ꢀ mL,ꢀ 0.01ꢀ mol/L)ꢀ wasꢀ addedꢀ toꢀ aꢀ three‐neckedꢀ flaskꢀ con‐
1
tainingꢀ H
2
Oꢀ (50ꢀ mL),ꢀ andꢀ theꢀ pHꢀ wasꢀ adjustedꢀ toꢀ 5.0ꢀ byꢀ
COOHꢀ (1ꢀ mol/L).ꢀ Theꢀ
ꢀ bubblingꢀ forꢀ aboutꢀ 20ꢀ min;ꢀ
‐(dimethylamino)ethanethiolꢀ (10ꢀ mL,ꢀ 0.05ꢀ mol/L)ꢀ wasꢀ thenꢀ
drop‐wiseꢀ additionꢀ ofꢀ aꢀ solutionꢀ ofꢀ CH
solutionꢀ wasꢀ saturatedꢀ byꢀ N
2
3
2
addedꢀtoꢀtheꢀSnCl ꢀsolutionꢀunderꢀcontinuousꢀvigorousꢀstirringꢀ
2
inꢀaꢀN
.01ꢀmol/L)ꢀwasꢀadded,ꢀandꢀtheꢀsolutionꢀwasꢀvigorouslyꢀstirredꢀ
underꢀN ꢀforꢀaboutꢀ10ꢀmin.ꢀFinally,ꢀtheꢀsolutionꢀpHꢀwasꢀadjust‐
edꢀtoꢀ6.0ꢀbyꢀ drop‐wiseꢀadditionꢀofꢀaꢀ solutionꢀ ofꢀCH COOHꢀ (1ꢀ
mol/L).ꢀTheꢀsolutionꢀwasꢀkeptꢀforꢀ120ꢀminꢀatꢀroomꢀtempera‐
tureꢀ(25ꢀ°C).ꢀTheꢀsolutionꢀturnedꢀlightꢀbrownꢀafterꢀ30ꢀmin,ꢀin‐
dicatingꢀtheꢀinitialꢀformationꢀofꢀSnS‐NPs,ꢀandꢀremainedꢀoptical‐
lyꢀclear.ꢀ
2
ꢀatmosphere.ꢀAfterꢀaboutꢀ10ꢀmin,ꢀthioacetamideꢀ(10ꢀmL,ꢀ
0
2.3.ꢀ ꢀ DeterminationꢀofꢀSnꢀcontentꢀofꢀSnS‐NPs@ACꢀ
2
3
SnS‐NPs@ACꢀ(100ꢀmg)ꢀwasꢀextractedꢀwithꢀconcentratedꢀHClꢀ
(5ꢀ ×ꢀ 2ꢀ mL)ꢀ inꢀ aꢀ screw‐cappedꢀ vessel,ꢀ followedꢀ byꢀ treatmentꢀ
withꢀconcentratedꢀnitricꢀacidꢀ(2ꢀmL)ꢀtoꢀdigestꢀtheꢀmetalꢀcom‐
plex.ꢀ Theꢀ mixtureꢀ wasꢀ thenꢀ transferredꢀ toꢀ aꢀ volumetricꢀ flaskꢀ
(100ꢀmL),ꢀdilutedꢀ1:50ꢀaꢀsecondꢀtime,ꢀandꢀanalyzedꢀusingꢀin‐
ductivelyꢀ coupledꢀ plasmaꢀ atomicꢀ emissionꢀ spectroscopyꢀ
CH
3
Ar
2+
H
3
C
(ICP‐AES).ꢀ Theꢀ Sn ꢀ concentrationꢀ wasꢀ determinedꢀ fromꢀ theꢀ
CN
NH
O
N
EtOH, reflux
atomicꢀemissionsꢀ(430ꢀnm)ꢀbyꢀreferenceꢀtoꢀaꢀlinearꢀ(Rꢀ=ꢀ0.99)ꢀ
+
NC
CN
+
N
N
Ar
H
SnS-NPs@AC
(5 mol%)
N
O
calibrationꢀcurveꢀforꢀSn(NO
3
) ꢀ(1–4ꢀppm)ꢀpreparedꢀinꢀaꢀmannerꢀ
2
2
Ph
O
Ph
1
2a-2s
identicalꢀtoꢀtheꢀSnS‐NPs@ACꢀsampleꢀpreparation.ꢀTheꢀICP‐AESꢀ
analysisꢀ showedꢀ thatꢀ theꢀ SnSꢀ contentꢀ ofꢀ theꢀ heterogeneousꢀ
catalystꢀ wasꢀ 7.5ꢀ wt%.ꢀ Theꢀ loadingꢀ onꢀ theꢀ supportedꢀ catalystꢀ
Schemeꢀ 1.ꢀ Synthesisꢀ ofꢀ 4H‐pyrano[2,3‐c]pyrazoleꢀ derivativesꢀ usingꢀ
SnS‐NPs@AC.ꢀ

628ꢀ
NasirꢀIravaniꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ36ꢀ(2015)ꢀ626–633ꢀ
wasꢀthereforeꢀcalculatedꢀtoꢀbeꢀ0.5ꢀmmolꢀSnS/gꢀofꢀtheꢀpreparedꢀ
catalyst.ꢀ Theꢀ sameꢀ procedureꢀ wasꢀ usedꢀ toꢀ measureꢀ leachingꢀ
fromꢀtheꢀsupportedꢀcatalystꢀafterꢀeightꢀconsecutiveꢀruns.ꢀ ꢀ
0.34ꢀ gꢀ (90%).ꢀ m.p.ꢀ 196–198ꢀ °Cꢀ (197–198ꢀ °C).ꢀ IRꢀ (KBr):ꢀ υꢀ =ꢀ
3391,ꢀ3312,ꢀ3196,ꢀ2923,ꢀ2201,ꢀ1651,ꢀ1590,ꢀ1515,ꢀ1452,ꢀ1393,ꢀ
−1 1
1343,ꢀ1261ꢀcm .ꢀ HꢀNMR:ꢀδꢀ=ꢀ1.80ꢀ(3H,ꢀs,ꢀCH
3
),ꢀ4.93ꢀ(1H,ꢀs,ꢀCH),ꢀ
7
.34ꢀ(2H,ꢀt,ꢀ3JHHꢀ=ꢀ7.6ꢀHz,ꢀ2CH),ꢀ7.69ꢀ(2H,ꢀs,ꢀNH
2
),ꢀ7.51(2H,ꢀt,ꢀ3JHH
ꢀ
ꢀ
2.4.ꢀ ꢀ Generalꢀprocedureꢀforꢀsynthesisꢀofꢀ
H‐pyrano[2,3‐c]pyrazolesꢀ ꢀ
=ꢀ8.4ꢀHz,ꢀ2CH),ꢀ7.59ꢀ(2H,ꢀd,ꢀ3JHHꢀ=ꢀ8.8ꢀHz,ꢀ2CH),ꢀ7.80ꢀ(2H,ꢀd,ꢀ3JHH
=ꢀ8.4ꢀHz,ꢀ2CH),ꢀ8.24ꢀ(2H,ꢀd,ꢀ3JHHꢀ=ꢀ8.8ꢀHz,ꢀ2CH)ꢀppm.ꢀ CꢀNMR:ꢀδꢀ
13
4
=ꢀ13.6,ꢀ37.4,ꢀ57.9,ꢀ98.7,ꢀ120.8,ꢀ121.2,ꢀ124.9,ꢀ127.4,ꢀ130.3,ꢀ130.4,ꢀ
3‐Methyl‐1‐phenyl‐2‐pyrazolin‐5‐oneꢀ (1ꢀ mmol),ꢀ anꢀ aro‐
138.5,ꢀ145.1,ꢀ146.2,ꢀ147.7,ꢀ152.3,ꢀ160.8ꢀppm.ꢀ
maticꢀ aldehydeꢀ (1ꢀ mmol),ꢀ andꢀ malononitrileꢀ (1ꢀ mmol)ꢀ wereꢀ
placedꢀ inꢀ aꢀ round‐bottomedꢀ flaskꢀ containingꢀ ethanolꢀ (5ꢀ mL).ꢀ
SnS‐NPs@ACꢀ (5ꢀmol%,ꢀ0.1ꢀg)ꢀ wasꢀ addedꢀtoꢀtheꢀmixture.ꢀ Theꢀ
suspensionꢀ wasꢀ magneticallyꢀ stirredꢀ underꢀ refluxꢀ conditionsꢀ
forꢀanꢀappropriateꢀtimeꢀ(seeꢀTableꢀ2).ꢀAfterꢀcompletionꢀofꢀtheꢀ
reaction,ꢀwhichꢀwasꢀmonitoredꢀbyꢀTLCꢀ(n‐hexane:ethylꢀacetateꢀ
6‐Amino‐4‐(2‐chlorophenyl)‐3‐methyl‐1‐phenyl‐1,4‐dihydro‐
pyrano[2,3‐c]pyrazole‐5‐carbonitrileꢀ (5i).ꢀ Yellowꢀ powder.ꢀ
Yield:ꢀ0.32ꢀgꢀ(89%).ꢀm.p.ꢀ142–144ꢀ°Cꢀ(140–142ꢀ°C).ꢀIRꢀ(KBr):ꢀυꢀ
=ꢀ3379,ꢀ3191,ꢀ3064,ꢀ2969,ꢀ2188,ꢀ1661,ꢀ1592,ꢀ1513,ꢀ1395,ꢀ1263,ꢀ
−1 1
1126ꢀcm .ꢀ HꢀNMR:ꢀδꢀ=ꢀ1.89ꢀ(3H,ꢀs,ꢀCH
3
),ꢀ4.73ꢀ(2H,ꢀs,ꢀNH ),ꢀ5.31ꢀ
2
(1H,ꢀ s,ꢀ CH),ꢀ 7.22–7.31ꢀ (3H,ꢀ m,ꢀ 3CH),ꢀ 7.33–7.34ꢀ (1H,ꢀ m,ꢀ CH),ꢀ
7.39–7.71ꢀ(1H,ꢀm,ꢀCH),ꢀ7.46–7.49ꢀ(2H,ꢀm,ꢀ2CH),ꢀ7.65–7.67ꢀ(2H,ꢀ
=
×
ꢀ3:1),ꢀtheꢀcatalystꢀwasꢀfilteredꢀandꢀwashedꢀwithꢀhotꢀethanolꢀ(2ꢀ
ꢀ 5ꢀ mL).ꢀ Theꢀ recoveredꢀ catalystꢀ wasꢀ washedꢀ withꢀ acetone,ꢀ
13
m,ꢀ2CH)ꢀppm.ꢀ CꢀNMR:ꢀδꢀ=ꢀ13.8,ꢀ35.1,ꢀ63.3,ꢀ99.2,ꢀ120.0,ꢀ122.3,ꢀ
127.9,ꢀ 128.7,ꢀ 129.9,ꢀ 130.4,ꢀ 131.1,ꢀ 131.8,ꢀ 134.5,ꢀ 138.6,ꢀ 140.3,ꢀ
145.1,ꢀ147.3,ꢀ160.1ꢀppm.ꢀ
dried,ꢀandꢀstoredꢀforꢀfurtherꢀsimilarꢀconsecutiveꢀruns.ꢀTheꢀfil‐
trateꢀ mixtureꢀ wasꢀ recrystallizedꢀ toꢀ provideꢀ pureꢀ crystalsꢀ ofꢀ
4
H‐pyrano[2,3‐c]pyrazoleꢀ derivatives.ꢀ Theꢀ productsꢀ wereꢀ
6‐Amino‐4‐(4‐chlorophenyl)‐3‐methyl‐1‐phenyl‐1,4‐dihydro‐
pyrano[2,3‐c]pyrazole‐5‐carbonitrileꢀ (5j).ꢀ Yellowꢀ powder.ꢀ
Yield:ꢀ0.31ꢀgꢀ(87%).ꢀm.p.ꢀ174–176ꢀ°Cꢀ(175–178ꢀ°C).ꢀIRꢀ(KBr):ꢀυꢀ
=ꢀ3459,ꢀ3326,ꢀ3199,ꢀ2923,ꢀ2198,ꢀ1658,ꢀ1594,ꢀ1521,ꢀ1495,ꢀ1470,ꢀ
knownꢀ compoundsꢀ andꢀ wereꢀ characterizedꢀ basedꢀ onꢀ IRꢀ andꢀ
NMRꢀ spectroscopicꢀ data.ꢀ Theirꢀ meltingꢀ pointsꢀ (m.p.)ꢀ wereꢀ
comparedꢀwithꢀreportedꢀvaluesꢀ[25–42].ꢀ
−1 1
1
395,ꢀ1269ꢀcm .ꢀ HꢀNMR:ꢀδꢀ=ꢀ1.77ꢀ(3H,ꢀs,ꢀCH
7.31ꢀ(1H,ꢀt,ꢀ3JHHꢀ=ꢀ7.6ꢀHz,ꢀCH),ꢀ7.32–7.34ꢀ(2H,ꢀm,ꢀ2CH),ꢀ7.37ꢀ(2H,ꢀ
s,ꢀNH
),ꢀ7.41ꢀ(1H,ꢀd,ꢀ3JHHꢀ=ꢀ7.6ꢀHz,ꢀCH),ꢀ7.43ꢀ(1H,ꢀd,ꢀ3JHHꢀ=ꢀ7.6ꢀHz,ꢀ
CH),ꢀ 7.46–7.51ꢀ (2H,ꢀ m,ꢀ 2CH),ꢀ 7.61ꢀ (1H,ꢀ d,ꢀ 3JHHꢀ =ꢀ 7.6ꢀ Hz,ꢀ CH),ꢀ
3
),ꢀ5.15ꢀ(1H,ꢀs,ꢀCH),ꢀ
2.5.ꢀ ꢀ Spectroscopicꢀdataꢀforꢀselectedꢀproductsꢀ
2
6‐Amino‐4‐(4‐methoxyphenyl)‐3‐methyl‐1‐phenyl‐1,4‐dihydro‐
13
pyrano[2,3‐c]pyrazole‐5‐carbonitrileꢀ(5e).ꢀPaleꢀyellowꢀpowder.ꢀ
Yield:ꢀ0.32ꢀgꢀ(89%).ꢀm.p.ꢀ241–243ꢀ°Cꢀ(242–243ꢀ°C).ꢀIRꢀ(KBr):ꢀυꢀ
7.76–7.78ꢀ(2H,ꢀm,ꢀ2CH)ꢀppm.ꢀ CꢀNMR:ꢀδꢀ=ꢀ12.4,ꢀ33.6,ꢀ56.2,ꢀ97.3,ꢀ
119.6,ꢀ 120.1,ꢀ 126.2,ꢀ 128.1,ꢀ 128.9,ꢀ 129.4,ꢀ 132.6,ꢀ 133.1,ꢀ 137.4,ꢀ
139.3,ꢀ144.3,ꢀ144.8,ꢀ159.9ꢀppm.ꢀ ꢀ
=ꢀ3394,ꢀ3325,ꢀ3059,ꢀ2975,ꢀ2193,ꢀ1661,ꢀ1597,ꢀ1515,ꢀ1397,ꢀ1258ꢀ
−1 1
cm .ꢀ HꢀNMR:ꢀ δꢀ=ꢀ1.78ꢀ(3H,ꢀs,ꢀCH
3
),ꢀ 3.74ꢀ (3H,ꢀ s,ꢀ OCH
1H,ꢀs,ꢀCH),ꢀ6.89ꢀ(2H,ꢀd,ꢀJꢀ=ꢀ8.5ꢀHz,ꢀ2CH),ꢀ7.15ꢀ(2H,ꢀs,ꢀ2CH),ꢀ7.17ꢀ
2H,ꢀs,ꢀNH ),ꢀ7.31ꢀ(1H,ꢀt,ꢀJꢀ=ꢀ7.6ꢀHz,ꢀCH),ꢀ7.49ꢀ(2H,ꢀt,ꢀJꢀ=ꢀ7.6ꢀHz,ꢀ
3
),ꢀ 4.62ꢀ
6‐Amino‐4‐(2,4‐dichlorophenyl)‐3‐methyl‐1‐phenyl‐1,4‐dihy‐
dropyrano[2,3‐c]pyrazole‐5‐carbonitrileꢀ (5l).ꢀ Yellowꢀ powder.ꢀ
Yield:ꢀ0.36ꢀgꢀ(90%).ꢀm.p.ꢀ180–182ꢀ°Cꢀ(182–184ꢀ°C).ꢀIRꢀ(KBr):ꢀυꢀ
=ꢀ3455,ꢀ3324,ꢀ3060,ꢀ2918,ꢀ2197,ꢀ1660,ꢀ1588,ꢀ1519,ꢀ1394,ꢀ1267,ꢀ
(
(
2
13
2
5
1
CH),ꢀ7.77ꢀ(2H,ꢀd,ꢀJꢀ=ꢀ8.5ꢀHz,ꢀ2CH)ꢀppm.ꢀ CꢀNMR:ꢀδꢀ=ꢀ12.6,ꢀ35.9,ꢀ
5.1,ꢀ58.6,ꢀ98.9,ꢀ113.8,ꢀ119.9,ꢀ120.1,ꢀ126.2,ꢀ128.8,ꢀ129.4,ꢀ135.6,ꢀ
37.5,ꢀ145.4,ꢀ158.2,ꢀ159.3ꢀppm.ꢀ
−
1 1
1182,ꢀ 1125ꢀ cm .ꢀ Hꢀ NMR:ꢀ δꢀ=ꢀ1.91ꢀ(3H,ꢀ s,ꢀ CH
NH ),ꢀ5.28ꢀ(1H,ꢀs,ꢀCH),ꢀ7.14–7.16ꢀ(1H,ꢀm,ꢀCH),ꢀ7.25–7.27ꢀ(1H,ꢀm,ꢀ
CH),ꢀ7.34–7.36ꢀ(1H,ꢀm,ꢀCH),ꢀ7.44–7.48ꢀ(3H,ꢀm,ꢀ3CH),ꢀ7.65ꢀ(2H,ꢀ
3
),ꢀ 4.74ꢀ (2H,ꢀ s,ꢀ
2
6‐Amino‐4‐(3,4,5‐trimethoxyphenyl)‐3‐methyl‐1‐phenyl‐1,4‐
1
3
dihydropyrano[2,3‐c]pyrazole‐5‐carbonitrileꢀ (5f).ꢀ Yellowꢀ
powder.ꢀYield:ꢀ0.36ꢀgꢀ(86%).ꢀm.p.ꢀ194–196ꢀ°Cꢀ(194–196ꢀ°C).ꢀIRꢀ
m,ꢀ2CH)ꢀppm.ꢀ CꢀNMR:ꢀδꢀ=ꢀ14.1,ꢀ38.1,ꢀ65.2,ꢀ99.7,ꢀ115.7,ꢀ122.3,ꢀ
127.8,ꢀ127.9,ꢀ128.8,ꢀ130.4,ꢀ138.7,ꢀ144.9,ꢀ149.2ꢀppm.ꢀ ꢀ
(
1
KBr):ꢀ υꢀ =ꢀ 3460,ꢀ 3325,ꢀ 3189,ꢀ 2940,ꢀ 2197,ꢀ 1657,ꢀ 1595,ꢀ 1521,ꢀ
6‐Amino‐4‐(4‐cyanophenyl)‐3‐methyl‐1‐phenyl‐1,4‐dihydro‐
pyrano[2,3‐c]pyrazole‐5‐carbonitrileꢀ(5n).ꢀPaleꢀyellowꢀpowder.ꢀ
Yield:ꢀ0.30ꢀgꢀ(85%).ꢀm.p.ꢀ215–217ꢀ°Cꢀ(217–218ꢀ°C).ꢀIRꢀ(KBr):ꢀυꢀ
=ꢀ3396,ꢀ3307,ꢀ3197,ꢀ2986,ꢀ2233,ꢀ2187,ꢀ1652,ꢀ1590,ꢀ1513,ꢀ1449,ꢀ
−1 1
459,ꢀ1390,ꢀ1129ꢀcm .ꢀ HꢀNMR:ꢀδꢀ=ꢀ1.86ꢀ(3H,ꢀs,ꢀCH
),ꢀ3.73ꢀ(6H,ꢀs,ꢀ2OCH ),ꢀ4.66ꢀ(1H,ꢀs,ꢀCH),ꢀ6.55ꢀ(2H,ꢀs,ꢀNH
.20ꢀ(2H,ꢀs,ꢀ2CH),ꢀ7.31ꢀ(1H,ꢀt,ꢀJꢀ=ꢀ7.4ꢀHz,ꢀCH),ꢀ7.49ꢀ(2H,ꢀt,ꢀJꢀ=ꢀ7.6ꢀ
3
),ꢀ3.65ꢀ(3H,ꢀ
s,ꢀOCH
7
3
3
2
),ꢀ
13
−1 1
Hz,ꢀ2CH),ꢀ7.78ꢀ(2H,ꢀd,ꢀJꢀ=ꢀ7.6ꢀHz,ꢀ2CH)ꢀppm.ꢀ CꢀNMR:ꢀδꢀ=ꢀ12.8,ꢀ
1385,ꢀ1262,ꢀ1120ꢀcm .ꢀ HꢀNMR:ꢀδꢀ=ꢀ1.89ꢀ(3H,ꢀs,ꢀCH
3
),ꢀ4.75ꢀ(1H,ꢀ
3
1
7.0,ꢀ 55.9,ꢀ 57.9,ꢀ 60.0,ꢀ 98.4,ꢀ 105.0,ꢀ 119.9,ꢀ 120.1,ꢀ 126.2,ꢀ 129.4,ꢀ
36.4,ꢀ137.6,ꢀ139.3,ꢀ143.8,ꢀ145.4,ꢀ152.9,ꢀ159.6ꢀppm.ꢀ
s,ꢀCH),ꢀ4.79ꢀ(2H,ꢀs,ꢀNH ),ꢀ7.35–7.37ꢀ(1H,ꢀm,ꢀCH),ꢀ7.39–7.41ꢀ(2H,ꢀ
2
m,ꢀ2CH),ꢀ7.47–7.50ꢀ(2H,ꢀm,ꢀ2CH),ꢀ7.64–7.69ꢀ(4H,ꢀm,ꢀ4CH)ꢀppm.ꢀ
13Cꢀ NMR:ꢀ δꢀ =ꢀ 14.1,ꢀ 38.7,ꢀ 61.1,ꢀ 63.6,ꢀ 98.3,ꢀ 112.8,ꢀ 119.7,ꢀ 122.5,ꢀ
128.2,ꢀ129.9,ꢀ130.5,ꢀ133.9,ꢀ138.5,ꢀ147.2,ꢀ148.4,ꢀ159.6ꢀppm.ꢀ ꢀ
6‐Amino‐4‐(4‐bromophenyl)‐3‐methyl‐1‐phenyl‐1,4‐dihydro‐
pyrano[2,3‐c]pyrazole‐5‐carbonitrileꢀ (5q).ꢀ Whiteꢀ powder.ꢀ
Yield:ꢀ0.36ꢀgꢀ(89%).ꢀm.p.ꢀ184–186ꢀ°Cꢀ(184–186ꢀ°C).ꢀIRꢀ(KBr):ꢀυꢀ
=ꢀ3450,ꢀ3330,ꢀ2949,ꢀ2198,ꢀ1661,ꢀ1589,ꢀ1515,ꢀ1452,ꢀ1393,ꢀ1259,ꢀ
6‐Amino‐4‐(3‐nitrophenyl)‐3‐methyl‐1‐phenyl‐1,4‐dihydropy‐
rano[2,3‐c]pyrazole‐5‐carbonitrileꢀ (5g).ꢀYellowꢀpowder.ꢀYield:ꢀ
0
3
1
4
2
.33ꢀ gꢀ (88%).ꢀ m.p.ꢀ 190–192ꢀ °Cꢀ (189–191ꢀ °C).ꢀ IRꢀ (KBr):ꢀ υꢀ =ꢀ
436,ꢀ3296,ꢀ3098,ꢀ2190,ꢀ1651,ꢀ1589,ꢀ1517,ꢀ1446,ꢀ1386,ꢀ1349,ꢀ
258,ꢀ1119ꢀcm .ꢀ HꢀNMR:ꢀδꢀ=ꢀ1.90ꢀ(3H,ꢀs,ꢀCH
.83ꢀ (2H,ꢀ s,ꢀ NH ),ꢀ 7.36–7.37ꢀ (1H,ꢀ m,ꢀ CH),ꢀ 7.48–7.51ꢀ (2H,ꢀ m,ꢀ
−1 1
3
),ꢀ4.81ꢀ(1H,ꢀs,ꢀCH),ꢀ
2
−1 1
CH),ꢀ7.56–7.59ꢀ(1H,ꢀm,ꢀCH),ꢀ7.66–7.67ꢀ(3H,ꢀm,ꢀ3CH),ꢀ8.13ꢀ(1H,ꢀ
1175ꢀcm .ꢀ HꢀNMR:ꢀδꢀ=ꢀ1.90ꢀ(3H,ꢀs,ꢀCH
3
),ꢀ4.64–4.69ꢀ(3H,ꢀm,ꢀCH,ꢀ
s,ꢀCH),ꢀ8.19ꢀ(1H,ꢀd,ꢀ3JHHꢀ=ꢀ7.2ꢀHz,ꢀCH)ꢀppm.ꢀ CꢀNMR:ꢀδꢀ=ꢀ13.0,ꢀ
13
NH ),ꢀ7.13–7.15ꢀ(2H,ꢀm,ꢀ2CH),ꢀ7.33–7.35ꢀ(H,ꢀm,ꢀCH),ꢀ7.48–7.50ꢀ
2
13
36.8,ꢀ57.6,ꢀ98.0,ꢀ120.3,ꢀ120.5,ꢀ122.7,ꢀ126.7,ꢀ129.7,ꢀ130.7,ꢀ135.2,ꢀ
(4H,ꢀm,ꢀ4CH),ꢀ7.64–7.66ꢀ(2H,ꢀm,ꢀ2CH)ꢀppm.ꢀ CꢀNMR:ꢀδꢀ=ꢀ13.1,ꢀ
36.7,ꢀ58.2,ꢀ98.6,ꢀ120.4,ꢀ120.5,ꢀ120.6,ꢀ126.7,ꢀ129.9,ꢀ129.8,ꢀ130.5,ꢀ
131.9,ꢀ137.9,ꢀ143.6,ꢀ144.4,ꢀ1415.7,ꢀ159.9ꢀppm.ꢀ
137.9,ꢀ144.5,ꢀ145.6,ꢀ146.4,ꢀ184.4,ꢀ160.3ꢀppm.ꢀ
6‐Amino‐4‐(4‐nitrophenyl)‐3‐methyl‐1‐phenyl‐1,4‐dihydropy‐
rano[2,3‐c]pyrazole‐5‐carbonitrileꢀ(5h).ꢀYellowꢀpowder.ꢀYield:ꢀ

ꢀ
NasirꢀIravaniꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ36ꢀ(2015)ꢀ626–633ꢀ
629ꢀ
3.ꢀ ꢀ Resultsꢀandꢀdiscussionꢀ
3.1.ꢀ ꢀ PreparationꢀofꢀSnS‐NPs@ACꢀcatalystꢀ
Theꢀ SnS‐NPs@ACꢀ catalystꢀ wasꢀ easilyꢀ preparedꢀ usingꢀ aꢀ
two‐stepꢀ procedure.ꢀ Theꢀ ACꢀ wasꢀ refluxedꢀ withꢀ aꢀ nitricꢀ acidꢀ
solutionꢀforꢀ12ꢀhꢀandꢀwashedꢀwithꢀdeionizedꢀwaterꢀuntilꢀtheꢀpHꢀ
wasꢀ 6–7ꢀ andꢀ thenꢀ driedꢀ inꢀ anꢀ ovenꢀ overnightꢀ underꢀ vacuum.ꢀ
TheꢀoxidizedꢀACꢀwasꢀuniformlyꢀmixedꢀwithꢀaꢀfreshlyꢀpreparedꢀ
SnS‐NPꢀ solutionꢀ (preparedꢀ byꢀ additionꢀ ofꢀ 2‐
mino)ethanethiolꢀandꢀthioacetamideꢀtoꢀanꢀaqueousꢀsolutionꢀofꢀ
SnCl ·2H Oꢀ inꢀ aꢀ N ꢀ atmosphere).ꢀ Finally,ꢀ theꢀ mixtureꢀ wasꢀ
ꢀ
(dimethyla‐
2
2
2
stirredꢀandꢀmaintainedꢀatꢀroomꢀtemperatureꢀforꢀseveralꢀhours,ꢀ
resultingꢀinꢀdirectꢀgrowthꢀofꢀSnS‐NPs@ACꢀinꢀtheꢀsolution.ꢀTheꢀ
SnS‐NPs@ACꢀwasꢀfiltered,ꢀwashedꢀwithꢀdoubly‐distilledꢀwater,ꢀ
andꢀdriedꢀatꢀ110ꢀ°C.ꢀThisꢀimmobilizationꢀprocedureꢀisꢀquickꢀandꢀ
simple,ꢀusesꢀreadilyꢀavailableꢀAC,ꢀandꢀdoesꢀnotꢀrequireꢀcatalystꢀ
modificationꢀtoꢀenableꢀimmobilization.ꢀ
Fig.ꢀ 2.ꢀ XRDꢀ patternsꢀ ofꢀ (a)ꢀ freshꢀ SnS‐NPs@ACꢀ andꢀ (b)ꢀ usedꢀ
SnS‐NPs@ACꢀafterꢀtheꢀeighthꢀrun.ꢀ
broadꢀpeaksꢀobservedꢀatꢀaroundꢀ26.20°,ꢀ31.45°,ꢀ37.86°,ꢀ51.25°,ꢀ
andꢀ64.40°ꢀindicateꢀthatꢀtheꢀSn‐NPsꢀhaveꢀanꢀorthorhombicꢀlat‐
ticeꢀstructureꢀ(mineralꢀherzenbergite)ꢀ[55].ꢀTheꢀbroadeningꢀofꢀ
theꢀXRDꢀpeaksꢀisꢀassociatedꢀwithꢀSnS‐NPꢀformation.ꢀTheꢀaver‐
ageꢀ nanocrystalliteꢀ sizeꢀ (D)ꢀ wasꢀ calculatedꢀ usingꢀ Scherrer’sꢀ
formulaꢀ[56]ꢀDꢀ=ꢀKλ/βcosθ,ꢀwhereꢀKꢀ(=ꢀ0.89)ꢀisꢀtheꢀshapeꢀfactor,ꢀ
3
.2.ꢀ ꢀ CharacterizationꢀofꢀSnS‐NPs@ACꢀcatalystꢀ
Theꢀ opticalꢀ propertiesꢀ ofꢀ theꢀ SnS‐NPs@ACꢀ wereꢀ deter‐
mined.ꢀFigureꢀ1ꢀshowsꢀtheꢀroom‐temperatureꢀUV‐Visꢀabsorp‐
tionꢀspectraꢀforꢀtheꢀSnS‐NPs.ꢀTheꢀabsorptionꢀedgesꢀofꢀtheꢀsam‐
plesꢀareꢀobservedꢀatꢀlowerꢀwavelengths,ꢀsignifyingꢀaꢀblueꢀshift.ꢀ
λꢀisꢀtheꢀwavelengthꢀofꢀCuꢀK
ꢀradiationꢀ(0.15406ꢀnm),ꢀθꢀisꢀtheꢀ
α
Theꢀvalueꢀofꢀtheꢀenergyꢀbandꢀgap,ꢀE
g
,ꢀwasꢀcalculatedꢀfromꢀtheꢀ
Braggꢀ angle,ꢀ andꢀ βꢀ isꢀ theꢀ experimentalꢀ full‐widthꢀ atꢀ
half‐maximumꢀofꢀtheꢀdiffractionꢀpeakꢀ(radians).ꢀTheꢀestimatedꢀ
averageꢀnanoparticleꢀsizeꢀwasꢀaboutꢀ64ꢀnm.ꢀItꢀalsoꢀshowsꢀthatꢀ
theꢀpatternsꢀofꢀtheꢀfreshꢀandꢀreusedꢀcatalystsꢀareꢀtheꢀsame;ꢀthisꢀ
indicatesꢀthatꢀtheꢀSnS‐NPsꢀareꢀretainedꢀonꢀtheꢀACꢀsurfaceꢀafterꢀ
eightꢀruns.ꢀ ꢀ
Theꢀ FE‐SEMꢀ imagesꢀ ofꢀ theꢀ ACꢀ surface,ꢀ SnS‐NPs,ꢀ andꢀ
SnS‐NPs@ACꢀ areꢀ shownꢀ inꢀ Fig.ꢀ 3.ꢀ Itꢀ canꢀ beꢀ seenꢀ thatꢀ theꢀ ACꢀ
surfaceꢀmorphologyꢀisꢀhomogeneousꢀandꢀrelativelyꢀsmoothꢀandꢀ
thatꢀtheꢀSnS‐NPsꢀdepositedꢀonꢀtheꢀACꢀareꢀhighlyꢀdispersedꢀonꢀ
theꢀ surface,ꢀ withoutꢀ anyꢀ aggregation,ꢀ andꢀ haveꢀ anꢀ approxi‐
matelyꢀuniformꢀsizeꢀdistribution.ꢀTheꢀsizeꢀandꢀmicrostructureꢀ
ofꢀ theꢀ SnS‐NPsꢀ wereꢀ alsoꢀ examinedꢀ usingꢀ FE‐SEM.ꢀ Theꢀ mor‐
phologyꢀofꢀtheꢀSnS‐NPsꢀcanꢀbeꢀclearlyꢀobservedꢀ(Fig.ꢀ3(c)).ꢀ ꢀ
TEMꢀimagesꢀofꢀtheꢀfreshꢀandꢀreusedꢀcatalystsꢀareꢀshownꢀinꢀ
Fig.ꢀ4.ꢀItꢀshowsꢀthatꢀtheꢀsizeꢀofꢀtheꢀnanoparticlesꢀimmobilizedꢀ
onꢀ theꢀ ACꢀ didꢀ notꢀ significantlyꢀ changeꢀ fromꢀ theꢀ firstꢀ toꢀ theꢀ
eighthꢀ runs.ꢀ Moreover,ꢀ noꢀ nanoparticleꢀ aggregationꢀ isꢀ seenꢀ
afterꢀtheꢀeighthꢀrun.ꢀ ꢀ
2
UV‐visꢀ spectrumꢀ byꢀ plottingꢀ (αhυ) ꢀ versusꢀ hυꢀ (inset)ꢀ [54],ꢀ
whereꢀ α,ꢀ h,ꢀ andꢀ υꢀ signifyꢀ theꢀ absorptionꢀ coefficient,ꢀ Planck’sꢀ
constant,ꢀandꢀfrequency,ꢀrespectively.ꢀItꢀisꢀclearꢀfromꢀFig.ꢀ1ꢀthatꢀ
theꢀbandꢀgapꢀchangedꢀfromꢀ1.83ꢀtoꢀ2.26ꢀeVꢀasꢀtheꢀnanocrystalꢀ
sizeꢀdecreased.ꢀInꢀaꢀtypicalꢀsynthesis,ꢀ smallꢀ particlesꢀ (i.e.,ꢀ nu‐
clei)ꢀappearedꢀatꢀpHꢀ6.0ꢀandꢀ25ꢀ°C.ꢀAsꢀtheꢀnanoparticlesꢀgrew,ꢀ
theꢀnumberꢀofꢀ particlesꢀquicklyꢀincreasedꢀtoꢀ aꢀmaximumꢀandꢀ
thenꢀ decreasedꢀ duringꢀ furtherꢀ growth.ꢀ Significantly,ꢀ someꢀ ofꢀ
theꢀ particlesꢀ formedꢀ inꢀ theꢀ initialꢀ stageꢀ disappearedꢀ afterꢀ
growthꢀ forꢀ 2ꢀ h,ꢀ butꢀ theꢀ sizeꢀ distributionꢀ ofꢀ theꢀ nanoparticlesꢀ
continuedꢀtoꢀnarrowꢀthroughoutꢀtheꢀsynthesis.ꢀ
Theꢀcrystallinityꢀofꢀtheꢀ SnS‐NPsꢀonꢀtheꢀ ACꢀsurfaceꢀ wasꢀin‐
vestigatedꢀusingꢀXRD;ꢀtheꢀresultsꢀareꢀshownꢀinꢀFig.ꢀ2.ꢀTheꢀfiveꢀ
TheꢀSnS‐NPꢀsizesꢀestimatedꢀfromꢀFE‐SEMꢀandꢀTEMꢀimagesꢀ
wereꢀ ofꢀ 40–90ꢀ andꢀ 30–70ꢀ nm,ꢀ respectively,ꢀ whichꢀ areꢀ inꢀ ac‐
cordanceꢀwithꢀtheꢀXRDꢀresultsꢀ(64ꢀnm).ꢀ
3.3.ꢀ ꢀ Optimizationꢀofꢀreactionꢀconditionsꢀ
ThereꢀareꢀnoꢀpreviousꢀreportsꢀofꢀtheꢀuseꢀofꢀSnSꢀorꢀitsꢀsup‐
portedꢀformꢀasꢀaꢀcatalystꢀinꢀorganicꢀsynthesis.ꢀWeꢀwereꢀthere‐
foreꢀinterestedꢀinꢀinvestigatingꢀtheꢀcatalyticꢀactivityꢀofꢀtheꢀpre‐
paredꢀ SnS‐NPs@ACꢀ asꢀ aꢀ newꢀ heterogeneousꢀ catalystꢀ forꢀ theꢀ
synthesisꢀ ofꢀ 4H‐pyrano[2,3‐c]pyrazoleꢀ derivatives.ꢀ Theꢀ reac‐
Fig.ꢀ1.ꢀTemporalꢀevolutionꢀofꢀabsorptionꢀspectrumꢀandꢀplotꢀofꢀ(αhυ)2
versusꢀ hυꢀ (inset)ꢀ ofꢀ nanoparticlesꢀ duringꢀ SnS‐NPꢀ synthesisꢀ atꢀ pHꢀ 6.0
andꢀ25ꢀ°C.ꢀ
tionꢀofꢀbenzaldehyde,ꢀmalononitrile,ꢀandꢀ3‐methyl‐1‐phenyl‐2‐
ꢀ
pyrazolin‐5‐oneꢀwasꢀselectedꢀasꢀaꢀmodelꢀreactionꢀtoꢀestablishꢀ

630ꢀ
NasirꢀIravaniꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ36ꢀ(2015)ꢀ626–633ꢀ
Fig.ꢀ3.ꢀFE‐SEMꢀimagesꢀofꢀACꢀ(a),ꢀSnS‐NPs@ACꢀ(b),ꢀandꢀSnS‐NPsꢀ(c).ꢀ
Fig.ꢀ4.ꢀTEMꢀimagesꢀofꢀ(a)ꢀfreshꢀSnS‐NPs@ACꢀandꢀ(b)ꢀusedꢀSnS‐NPs@ACꢀafterꢀtheꢀeighthꢀrun.ꢀ
theꢀreactionꢀconditions,ꢀandꢀtheꢀeffectsꢀofꢀdifferentꢀmolarꢀratiosꢀ
ofꢀtheꢀSnS‐NPs@ACꢀandꢀfreeꢀSnS‐NPsꢀwereꢀstudiedꢀunderꢀvari‐
ousꢀ conditionsꢀ (Tableꢀ 1).ꢀ Theꢀ greenꢀ solventsꢀ poly(ethyleneꢀ
ledꢀtoꢀdecreasedꢀyields.ꢀMoreover,ꢀtheꢀyieldꢀincreasedꢀslightlyꢀ
whenꢀtheꢀsameꢀmolarꢀratioꢀofꢀSnS‐NPs@ACꢀwasꢀusedꢀinsteadꢀofꢀ
theꢀ optimumꢀ neatꢀ SnS‐NPsꢀ (Tableꢀ 1,ꢀ entriesꢀ 3ꢀ andꢀ 6).ꢀ
SnS‐NPs@ACꢀwasꢀthereforeꢀtheꢀpreferredꢀformꢀofꢀtheꢀcatalyst,ꢀ
becauseꢀitꢀhasꢀadvantagesꢀsuchꢀasꢀaꢀsimpleꢀrecoveryꢀprocess,ꢀ
higherꢀyields,ꢀandꢀlessꢀproductꢀcontaminationꢀcomparedꢀwithꢀ
neatꢀSnS‐NPs.ꢀ
Theꢀ reactionsꢀ ofꢀ 3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐one,ꢀ
malononitrile,ꢀandꢀvariousꢀ aromaticꢀaldehydesꢀwereꢀexploredꢀ
usingꢀ5ꢀmol%ꢀSnS‐NPs@ACꢀinꢀethanolꢀunderꢀrefluxꢀconditionsꢀ
(Schemeꢀ1,ꢀTableꢀ2).ꢀAllꢀtheꢀproductsꢀwereꢀcleanlyꢀisolatedꢀbyꢀ
simpleꢀ filtrationꢀ andꢀ recrystallizationꢀ fromꢀ hotꢀ ethanol.ꢀ Asꢀ
glycol)ꢀ (PEG)ꢀ 300,ꢀ ethanol,ꢀ H
2
O,ꢀ ethanol/H O,ꢀ andꢀ PEGꢀ
2
3
00/H Oꢀwereꢀexamined.ꢀEthanol,ꢀwhichꢀclearlyꢀgaveꢀtheꢀfast‐
2
estꢀreactionꢀrateꢀandꢀhighestꢀyield,ꢀwasꢀchosenꢀasꢀtheꢀsolvent.ꢀAꢀ
comparisonꢀofꢀtheꢀyieldsꢀandꢀreactionꢀratesꢀwithꢀandꢀwithoutꢀ
SnS‐NPsꢀclearlyꢀshowedꢀtheꢀimportanceꢀofꢀtheꢀcatalystꢀ(entryꢀ1ꢀ
versusꢀentriesꢀ2–6).ꢀ
Theꢀyieldꢀsmoothlyꢀincreasedꢀwithꢀincreasingꢀcatalystꢀload‐
ingꢀ upꢀ toꢀ 5ꢀ mol%;ꢀ theꢀ useꢀ ofꢀ aꢀ largerꢀ amountꢀ ofꢀ catalystꢀ (10ꢀ
mol%)ꢀdidꢀnotꢀimproveꢀtheꢀyield,ꢀandꢀlowerꢀamountsꢀofꢀcatalystꢀ
Tableꢀ1ꢀ
CatalyticꢀactivitiesꢀofꢀSnS‐NPsꢀandꢀSnS‐NPs@ACꢀinꢀsynthesisꢀofꢀ4H‐pyrano[2,3‐c]pyrazoleꢀderivativesꢀunderꢀvariousꢀconditions.ꢀ
CH
3
O
H C
3
CN
NH
N
H
Conditions
+
NC
CN
+
N
N
N
O
2
ꢀ
Ph
O
Ph
a
Entryꢀ
Solventꢀ
Ethanolꢀ
Ethanolꢀ
Ethanolꢀ
Ethanolꢀ
Ethanolꢀ
Ethanolꢀ
Temperatureꢀ(°C)ꢀ
Refluxꢀ
Refluxꢀ
Refluxꢀ
Refluxꢀ
Refluxꢀ
Refluxꢀ
80ꢀ
Catalystꢀ
Timeꢀ(min)ꢀ
60ꢀ
Yieldꢀ ꢀ(%)ꢀ
1
ꢀ
Noꢀcatalystꢀ
SnSꢀnanoparticlesꢀ(2ꢀmol%,ꢀ0.003ꢀg)ꢀ
SnSnanoparticlesꢀ(5ꢀmol%,ꢀ0.008ꢀg)ꢀ
SnSnanoparticlesꢀ(10ꢀmol%,ꢀ0.015ꢀg)ꢀ
18ꢀ
66ꢀ
86ꢀ
87ꢀ
70ꢀ
91ꢀ
78ꢀ
70ꢀ
64ꢀ
78ꢀ
2
ꢀ
60ꢀ
20ꢀ
20ꢀ
20ꢀ
3
ꢀ
ꢀ
4
ꢀ
ꢀ
5
ꢀ
SnS‐NPs@ACꢀ(2ꢀmol%,ꢀ0.04ꢀg)ꢀ
SnS‐NPs@ACꢀ(5ꢀmol%,ꢀ0.1ꢀg)ꢀ
SnS‐NPs@ACꢀ(5ꢀmol%,ꢀ0.1ꢀg)ꢀ
SnS‐NPs@ACꢀ(5ꢀmol%,ꢀ0.1ꢀg)ꢀ
SnS‐NPs@ACꢀ(5ꢀmol%,ꢀ0.1ꢀg)ꢀ
SnS‐NPs@ACꢀ(5ꢀmol%,ꢀ0.1ꢀg)ꢀ
6ꢀ
20ꢀ
7
ꢀ
EtOH/H
2
Oꢀ(1:1)ꢀ
Oꢀ
PEG300ꢀ
PEG300/H Oꢀ(1:1)ꢀ
20ꢀ
30ꢀ
30ꢀ
30ꢀ
8
ꢀ
H
2
Refluxꢀ
60ꢀ
80ꢀ
9
ꢀ
10ꢀ
2
Reactionꢀconditions:ꢀbenzaldehydeꢀ(1ꢀmmol),ꢀmalononitrileꢀ(1ꢀmmol),ꢀ3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐oneꢀ(1ꢀmmol),ꢀsolventꢀ(10ꢀml).ꢀ
aꢀ
Yieldsꢀreferꢀtoꢀisolatedꢀandꢀpureꢀproducts.ꢀ

ꢀ
NasirꢀIravaniꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ36ꢀ(2015)ꢀ626–633ꢀ
631ꢀ
shownꢀinꢀTableꢀ2,ꢀinꢀallꢀcases,ꢀaromaticꢀaldehydesꢀsubstitutedꢀ
withꢀeitherꢀelectron‐donatingꢀorꢀelectron‐withdrawingꢀgroupsꢀ
smoothlyꢀunderwentꢀtheꢀreactionꢀandꢀgaveꢀtheꢀtargetꢀproductsꢀ
inꢀgoodꢀtoꢀexcellentꢀyieldsꢀ(2a–2s).ꢀItꢀshouldꢀbeꢀmentionedꢀthatꢀ
ourꢀ effortsꢀ toꢀ synthesizeꢀ 4H‐pyrano[2,3‐c]pyrazolesꢀusingꢀ ali‐
phaticꢀaldehydesꢀwereꢀunsuccessful,ꢀprobablyꢀbecauseꢀofꢀalde‐
hydeꢀenolizationꢀduringꢀtheꢀreaction.ꢀ
zolin‐5‐oneꢀ undergoesꢀ protonꢀ transferꢀ viaꢀ tautomerizationꢀ toꢀ
giveꢀ intermediateꢀ 8.ꢀ Theꢀ reactionꢀ ofꢀ intermediatesꢀ 7ꢀ andꢀ 8ꢀ
yieldsꢀ intermediateꢀ 9.ꢀ Thisꢀ intermediateꢀ undergoesꢀ protonꢀ
transferꢀandꢀsubsequentꢀintramolecularꢀcyclizationꢀtoꢀformꢀtheꢀ
heterocyclicꢀ intermediateꢀ 10,ꢀ whichꢀ generatesꢀ 2ꢀ byꢀ protonꢀ
transferꢀviaꢀtautomerization.ꢀ
Itꢀ isꢀ alsoꢀ worthꢀ notingꢀ thatꢀ SnS‐NPs@ACꢀ doesꢀ notꢀ sufferꢀ
fromꢀ mechanicalꢀ degradationꢀ afterꢀ severalꢀ runs.ꢀ Forꢀ aꢀ good,ꢀ
efficientꢀheterogeneousꢀcatalyst,ꢀtheꢀsupportedꢀcatalystꢀshouldꢀ
notꢀleachꢀintoꢀtheꢀreactionꢀmixture,ꢀandꢀtheꢀrecyclabilityꢀofꢀtheꢀ
supportedꢀ catalystꢀ isꢀ alsoꢀ important.ꢀ Toꢀ investigateꢀ theseꢀ
AꢀplausibleꢀmechanismꢀforꢀthisꢀreactionꢀisꢀshownꢀinꢀSchemeꢀ
2
.ꢀCompoundꢀ2ꢀisꢀformedꢀbyꢀcondensationꢀofꢀtheꢀaromaticꢀal‐
dehydeꢀwithꢀmalononitrileꢀtoꢀproduceꢀalkylidenemalononitrileꢀ
.ꢀInꢀtheꢀpresenceꢀofꢀSnS‐NPs@AC,ꢀ3‐methyl‐1‐phenyl‐2‐
pyra‐
7
ꢀ
Tableꢀ2ꢀ
Synthesisꢀofꢀ4H‐pyrano[2,3‐c]pyrazoleꢀderivativesꢀcatalyzedꢀbyꢀSnS‐NPs@ACꢀ(Schemeꢀ1).ꢀ
m.p.ꢀ(°C)ꢀ
a
Entryꢀ
Arꢀ
Productꢀ
Timeꢀ(min)ꢀ
Yieldꢀ ꢀ(%)
Foundꢀ
Reportedꢀ
169–171ꢀ
190–192ꢀ
158–160ꢀ
234–236ꢀ
242–243ꢀ
194–196ꢀ
189–191ꢀ
197–198ꢀ
140–142ꢀ
175–178ꢀ
158–161ꢀ
182–184ꢀ
170–172ꢀ
217–218ꢀ
206–207ꢀ
207–209ꢀ
184–186ꢀ
217–219ꢀ
178–180ꢀ
1
ꢀ
C
6
H
6
5
ꢀ
2aꢀ
2bꢀ
2cꢀ
2dꢀ
2eꢀ
2fꢀ
2gꢀ
2hꢀ
2iꢀ
2jꢀ
2kꢀ
2lꢀ
2mꢀ
2nꢀ
2oꢀ
2pꢀ
2qꢀ
2rꢀ
2sꢀ
20ꢀ
25ꢀ
25ꢀ
25ꢀ
25ꢀ
25ꢀ
15ꢀ
18ꢀ
18ꢀ
15ꢀ
20ꢀ
15ꢀ
18ꢀ
15ꢀ
25ꢀ
20ꢀ
15ꢀ
15ꢀ
25ꢀ
91ꢀ
88ꢀ
87ꢀ
87ꢀ
89ꢀ
86ꢀ
88ꢀ
90ꢀ
89ꢀ
87ꢀ
91ꢀ
90ꢀ
87ꢀ
85ꢀ
89ꢀ
92ꢀ
89ꢀ
90ꢀ
90ꢀ
168–170ꢀ
190–192ꢀ
159–161ꢀ
235–237ꢀ
241–243ꢀ
194–196ꢀ
190–192ꢀ
196–198ꢀ
142–144ꢀ
174–176ꢀ
159–161ꢀ
180–182ꢀ
171–173ꢀ
215–217ꢀ
205–207ꢀ
206–208ꢀ
184–186ꢀ
217–220ꢀ
178–181ꢀ
2
ꢀ
4‐PhC
4‐MeC
4‐CHOC
4‐MeOC
3,4,5‐(MeO)
3‐NO
4‐NO
2‐ClC
4‐ClC
3‐ClC
2,4‐(Cl)
4‐FC
4‐CNC
4‐OHC
2‐OHC
H ꢀ
4
3
ꢀ
6
H ꢀ
4
4
ꢀ
6
H ꢀ
H ꢀ
4
5
ꢀ
6
4
6
ꢀ
3
C
6
H ꢀ
2
7
ꢀ
2
C
C
6
H
H
4
ꢀ
ꢀ
8
ꢀ
2
6
4
9
ꢀ
6
6
6
H
H
H
C
H
4
4
4
ꢀ
ꢀ
ꢀ
10ꢀ
11ꢀ
12ꢀ
13ꢀ
14ꢀ
15ꢀ
16ꢀ
17ꢀ
18ꢀ
19ꢀ
2
6
H
ꢀ
3
ꢀ
6
4
6
H ꢀ
4
6
H
4
ꢀ
ꢀ
6
H
4
4‐BrC
4‐CNC
2‐Naphthylꢀ
6
H ꢀ
4
6
H ꢀ
4
Reactionꢀconditions:ꢀAromaticꢀaldehydeꢀ(1ꢀmmol),ꢀmalononitrileꢀ(1ꢀmmol),ꢀ3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐oneꢀ(1ꢀmmol),ꢀSnS‐NPs@ACꢀ(5ꢀmolꢀ%,ꢀ
0
.10ꢀg),ꢀEtOHꢀ(10ꢀml),ꢀreflux.ꢀ
aꢀ
Yieldsꢀreferꢀtoꢀisolatedꢀandꢀpureꢀproducts.ꢀ
Schemeꢀ2.ꢀPlausibleꢀmechanismꢀforꢀsynthesisꢀofꢀ4H‐pyrano[2,3‐c]pyrazoleꢀderivativesꢀusingꢀSnS‐NPs@AC.ꢀ

632ꢀ
NasirꢀIravaniꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ36ꢀ(2015)ꢀ626–633ꢀ
investigated.ꢀInꢀtheꢀpresenceꢀofꢀSnS‐NPs@AC,ꢀallꢀtheꢀreactionsꢀ
1
00
100
80
60
40
20
0
Yield
Time
hadꢀshortꢀreactionꢀtimesꢀandꢀgaveꢀhighꢀyields.ꢀNanosizedꢀparti‐
cles,ꢀ withꢀ aꢀ highꢀ surface‐to‐volumeꢀ ratio,ꢀ simpleꢀ workupꢀ andꢀ
recovery,ꢀandꢀreusabilityꢀinꢀupꢀtoꢀeightꢀconsecutiveꢀruns,ꢀwithꢀ
veryꢀlowꢀleaching,ꢀmakeꢀthisꢀaꢀnew,ꢀefficient,ꢀandꢀsuperiorꢀcat‐
alystꢀ superiorꢀ forꢀ theꢀ synthesisꢀ ofꢀ 4H‐pyrano[2,3‐c]pyrazoleꢀ
derivatives.ꢀ Furtherꢀ catalyticꢀ usesꢀ ofꢀ SnS‐NPs@ACꢀ areꢀ underꢀ
investigationꢀinꢀourꢀlaboratories.ꢀ
8
6
4
2
0
0
0
0
0
Acknowledgmentsꢀ
Weꢀ areꢀ gratefulꢀ toꢀ Islamicꢀ Azadꢀ University,ꢀ Gachsaranꢀ
Branchꢀ andꢀ theꢀ Researchꢀ Councilꢀ ofꢀ Yasoujꢀ Universityꢀ forꢀ fi‐
nancialꢀsupport.ꢀ ꢀ
1
2
3
4
5
6
7
8
Run
Fig.ꢀ5.ꢀRecyclabilityꢀofꢀSnS‐NPs@AC.ꢀ
Referencesꢀ
propertiesꢀforꢀourꢀcatalyst,ꢀtheꢀreactionꢀofꢀ3‐methyl‐1‐phenyl‐
‐pyrazolin‐5‐one,ꢀbenzaldehyde,ꢀandꢀmalononitrileꢀinꢀethanolꢀ
wasꢀagainꢀselectedꢀasꢀaꢀmodelꢀreactionꢀ(Fig.ꢀ5).ꢀAfterꢀcomple‐
ꢀ
2
[1] BuzeaꢀC,ꢀPachecoꢀIꢀI,ꢀRobbieꢀK.ꢀBiointerphases,ꢀ2007,ꢀ2(4):ꢀMR17ꢀ ꢀ
[2] Astrucꢀ D.ꢀ Nanoparticlesꢀ andꢀ Catalysis.ꢀ Weinheim:ꢀ Wiley‐VCH,ꢀ
tionꢀ ofꢀ theꢀ reaction,ꢀ theꢀ mixtureꢀ wasꢀ filtered,ꢀ andꢀ completeꢀ
separationꢀofꢀtheꢀproductꢀfromꢀtheꢀsurfaceꢀofꢀtheꢀcatalystꢀwasꢀ
achievedꢀbyꢀwashingꢀtheꢀcatalystꢀwithꢀhotꢀethanolꢀ(2ꢀ×ꢀ5ꢀmL).ꢀ
Finally,ꢀ theꢀ recoveredꢀ catalystꢀ wasꢀ washedꢀ withꢀ acetoneꢀ andꢀ
driedꢀbeforeꢀuseꢀforꢀsevenꢀconsecutiveꢀruns.ꢀAlmostꢀconsistentꢀ
activityꢀwasꢀobservedꢀoverꢀsevenꢀconsecutiveꢀruns.ꢀFromꢀFig.ꢀ5,ꢀ
itꢀcanꢀbeꢀseenꢀthatꢀSnS‐NPs@ACꢀcanꢀbeꢀreusedꢀforꢀupꢀtoꢀeightꢀ
runsꢀwithoutꢀcatalystꢀreloading.ꢀTheꢀyieldꢀdifferenceꢀbetweenꢀ
theꢀfirstꢀandꢀeighthꢀrunsꢀwasꢀonlyꢀ5%,ꢀwhichꢀindicatesꢀthatꢀtheꢀ
catalyticꢀ efficiencyꢀ isꢀ almostꢀ completelyꢀ maintainedꢀ duringꢀ
eightꢀconsecutiveꢀruns.ꢀ ꢀ
2
008ꢀ
3] TianꢀN,ꢀZhouꢀZꢀY,ꢀYuꢀNꢀF,ꢀWangꢀLꢀY,ꢀSunꢀSꢀG.ꢀJꢀAmꢀChemꢀSoc,ꢀ2010,ꢀ
32:ꢀ7580ꢀ ꢀ
[
1
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Next,ꢀweꢀcheckedꢀtheꢀleachingꢀofꢀSnSꢀintoꢀtheꢀreactionꢀmix‐
tureꢀ fromꢀ theꢀ ACꢀ supportꢀ usingꢀ ICP‐AES.ꢀ Theꢀ differenceꢀ be‐
[
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gibleꢀleachingꢀofꢀSnSꢀintoꢀtheꢀreactionꢀmixture.ꢀTableꢀ3ꢀshowsꢀ
theꢀefficiencyꢀandꢀsuperiorityꢀofꢀtheꢀpresentꢀcatalystꢀcomparedꢀ
withꢀsomeꢀpreviouslyꢀreportedꢀcatalysts.ꢀ
[
[
14] PuaꢀFꢀL,ꢀChiaꢀCꢀH,ꢀZakariaꢀS,ꢀNeohꢀSꢀK,ꢀLiewꢀTꢀK.ꢀSainsꢀMalaysiana,ꢀ
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1:ꢀ5029ꢀ
2
4.ꢀ ꢀ Conclusionsꢀ
[
6
SnS‐NPsꢀ supportedꢀ onꢀ ACꢀ wereꢀ preparedꢀ usingꢀ aꢀ simpleꢀ
[
16] MaꢀL,ꢀChenꢀWꢀX,ꢀLiꢀH,ꢀZhengꢀYꢀF,ꢀXuꢀZꢀD.ꢀMaterꢀLett,ꢀ2008,ꢀ62:ꢀ797ꢀ
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resultsꢀshowedꢀthatꢀtheꢀsizeꢀofꢀtheꢀSnS‐NPsꢀimmobilizedꢀonꢀACꢀ
wasꢀ30–70ꢀnm.ꢀTheꢀcatalyticꢀefficiencyꢀofꢀtheꢀpreparedꢀcatalystꢀ
inꢀ theꢀ synthesisꢀ ofꢀ 4H‐pyrano[2,3‐c]pyrazoleꢀ derivativesꢀ wasꢀ
[
[
18] DaiꢀPꢀC,ꢀZhangꢀG,ꢀChenꢀYꢀC,ꢀJiangꢀHꢀC,ꢀFengꢀZꢀY,ꢀLinꢀZꢀJ,ꢀZhanꢀJꢀH.ꢀ
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Tableꢀ3ꢀ
Comparisonꢀofꢀefficienciesꢀofꢀpresentꢀandꢀpreviouslyꢀreportedꢀcatalysts.ꢀ
Entryꢀ
Catalystꢀ
SnS‐NPs@ACꢀ
γ‐Aluminaꢀ
Solventꢀ
Catalystꢀloadingꢀ
5ꢀmol%ꢀ
30ꢀmol%ꢀ
1ꢀmol%ꢀ
4ꢀmol%ꢀ
0.15ꢀgꢀ
Timeꢀ(min)ꢀ
ꢀ 20ꢀ
Isolatedꢀyieldꢀ(%)ꢀ
Ref.ꢀ
thisꢀworkꢀ
[26]ꢀ
[27]ꢀ
[37]ꢀ
1
ꢀ
EtOH,ꢀrefluxꢀ
91ꢀ
80ꢀ
93ꢀ
86ꢀ
99ꢀ
88ꢀ
97ꢀ
94ꢀ
86ꢀ
2
ꢀ
H
2
O,ꢀrefluxꢀ
EtOH,ꢀrefluxꢀ
O,ꢀrefluxꢀ
ꢀ 50ꢀ
ꢀ 55ꢀ
ꢀ 55ꢀ
360ꢀ
180ꢀ
ꢀ 25ꢀ
3
ꢀ
H
5 30
14[NaP W O110]ꢀ
4
ꢀ
PTSAꢀ
TEBAꢀ
DBSAꢀ
H
2
5
ꢀ
2
H O,ꢀ90ꢀ°Cꢀ
[38]ꢀ
[39]ꢀ
6
ꢀ
2
H O,ꢀ60ꢀ°Cꢀ
10ꢀmol%ꢀ
0.05ꢀgꢀ
7ꢀ
SBPPSPꢀ
EtOH/H
EtOH,ꢀrtꢀ
EtOH:H O,ꢀrefluxꢀ
2
O/100ꢀ°Cꢀ
[40]ꢀ
[41]ꢀ
[42]ꢀ
8
ꢀ
SB(DBU)Clꢀ
SB‐DABCOꢀ
5ꢀmol%ꢀ
6ꢀmol%ꢀ
ꢀ 35ꢀ
ꢀ 30ꢀ
9ꢀ
2

ꢀ
NasirꢀIravaniꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ36ꢀ(2015)ꢀ626–633ꢀ
GraphicalꢀAbstractꢀ
633ꢀ
Chin.ꢀJ.ꢀCatal.,ꢀ2015,ꢀ36:ꢀ626–633ꢀ ꢀ ꢀ doi:ꢀ10.1016/S1872‐2067(14)60284‐9
TinꢀsulfideꢀnanoparticlesꢀsupportedꢀonꢀactivatedꢀcarbonꢀasꢀanꢀefficientꢀandꢀreusableꢀLewisꢀacidꢀcatalystꢀforꢀthree‐componentꢀ
one‐potꢀsynthesisꢀofꢀ4H‐pyrano[2,3‐c]pyrazoleꢀderivativesꢀ
ꢀ
ꢀ
NasirꢀIravani*,ꢀMosadeghꢀKeshavarz*,ꢀHosseinꢀAliꢀShojaeianꢀKish,ꢀRasoolꢀParandvarꢀ
IslamicꢀAzadꢀUniversity,ꢀIran;ꢀYasoujꢀUniversity,ꢀIranꢀ
ꢀ
Tinꢀsulfideꢀnanoparticlesꢀimmobilizedꢀonꢀactivatedꢀcarbonꢀwereꢀshownꢀtoꢀbeꢀaꢀpowerfulꢀrecoverableꢀsolidꢀacidꢀcatalystꢀforꢀtheꢀprepara‐
tionꢀofꢀ4H‐pyrano[2,3‐c]pyrazoleꢀderivatives.ꢀ
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