reactive dyes 9丁思佳Word格式.docx

reactive dyes 9丁思佳Word格式.docx

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importanceofreactivedyesarerapidlygrowing

becauseoftheirwiderangeofhues,easy

applicationandexcellentwetfastnessproperties

（Stead,1982;

Pateletal.,2001）.

Thereactivedyesarewatersoluble,easilyapplied

andbecausethereactivegroupmaybeattachedto

almostanycolouredmolecularsystem,theycan

beusedtoproducebothverybrightandverydull

shadesofallcolours（Shah,1998）.

Themainadvantageofbisazodyesisthatthey

giveahigherfixationyieldandthendyewithone

reactivegroupbecauseifoneofthetwodye-fibre

bondishydrolysed,oneisstillleftforfixation

（Brederecketal.,1993）.

Thegrowinginterestinthe1,3,4-oxadiazole

chemistryliesindesigningnewsynthetic

approaches,suchasdifferentapplicationsofthis

moietywhichmakeitusefulinthe

pharmaceuticals,agrochemicalsanddyestuff

industries.The1,3,4-oxadiazolederivatives

possesshighelectronacceptingpropertiesand

strongfluorescencewithgreatquantumyields

（Hughesetal.,2005）.

Itisalsoaverygoodantimicrobialagent

（Bhardwajetal.,2009）.

Somebisazocompoundsthathave1,3,

4-oxadiazolestructuresshowgood

photoconductivity（Xueetal.,2007）andoptical

properties（Lvetal.,2010）.

Othercharacteristicsof1,3,4-oxadiazoleare

outstandingcapabilityoftransportingelectron,

goodthermostabilityandgoodantioxygenation

（Chenetal.,2002）whichmakesitmoreuseful.

Theoutstandingthermalstabilityof1,3,4-

oxadiazoleisattributedtothefactthatthe

oxadiazoleringiselectronicallyequivalenttothe

phenyleneringstructure,whichisknowntobe

highlythermoresistant.Also,itdoesnothaveany

hydrogenatoms,lackstension,doesnothaveany

possibilitiesofrearrangement,andisstructurally

*Correspondingauthor.Tel.:

（0261）2258384;

Fax:

（0261）2256012

E-mailaddress:

divyeshpatel905@（K.C.Patel）

RJTAVol.15No.22011

30

symmetric.Thesefeaturescausedyesthat

contain1,3,4-oxadiazolemoietiestobeconsidered

asalternativesforthedevelopmentofheat

flame-resistant,semi-conducting,fiber-forming

andthermallystablematerials（Hsiaoetal.,2001）.

Inaddition,byconjugationwithphenylrings,

oxadiazoleunitsshowblue-lightemittingbehavior

（Maetal.,2005;

Savaetal.,2003）.

Inthispaper,wereportthesynthesisof

1,3,4-oxadiazolebasedbisazoreactivedyes.To

achievethesynthesisoftheabovecompounds,

2,5-Bis（4-aminophenyl）-1,3,4-oxadiazolewas

tetrazotizedandcoupledwithvariouscyanurated

couplingcomponents.Theaimofthisworkisto

synthesizeaseriesofsuchbisazodyes,which

havebeensuccessfullytestedasreactivedyesfor

silk,woolandcottonfibres.Inadditiontothe

characterizationofthedyes,anevaluationoftheir

technicalpropertiesisalsoperformed.

2.Experimental

2.1MaterialsandMethod

Themeltingpoints（m.p.）weredeterminedbythe

opencapillarymethodandwerenotchanged.In

alltheexperimentstheheatingratewas2°

C

min-1.Thepurityofallthedyeswascheckedby

thinlayerchromatography（TLC,Friedetal.,

1982）.

TheIRspectra（Colthupetal.,1991;

Yuenetal.,

2005）wererecordedonaPerkinElmermodel881

spectrophotometerandthe1HNMRspectra

（Bassleretal.,1991）wererecordedonaBruker

AvanceII400instrumentusingtetramethylsilane

（TMS）astheinternalstandardanddimethyl

sulfoxide（DMSO）asthesolvent.Theabsorption

spectrawererecordedinwateronaBeckman

DB-GTgratingspectrophotometer.Anelemental

analysisofcarbon,hydrogenandnitrogen（C,H

andN）wascarriedonaCarloErba1108

instrument.Thelightfastnesswasassessedin

accordancewithBS:

1006-1978（StandardTest

Method,1978）.

Therubbingfastnesstestwascarriedoutwitha

crockmeter（Atlas）inaccordancewith

AATCC-1961（AATCCTestMethod,1961）and

thewashingfastnesstestinaccordancewithIS:

765-1979（IndianStandard,1979）.

Thepercentagedyebathexhaustion（%E）and

percentagedyebathfixation（%F）ofthedyed

fabricweredeterminedaccordingtotheknown

method（Shamsetal.,2009）.

2.2Synthesisof1,2-Bis（4-aminobenzoyl）-

hydrazine

Thesynthesisof1,2-Bis（4-aminobenzoyl）-

hydrazinewascarriedoutwithreferencetoQian

etal.（2007）Amixtureof13.7g（0.1mol）of

4-aminobenzoicacid,50mLofpolyphosphoric

acidand5g（0.05mol）ofhydrazinehydrate

wasstirredfor10hatatemperatureof130°

underanitrogenatmosphere.Themixturewas

pouredintoicewater,whichwasthenneutralized,

filteredandwashedwithwateranddilutesodium

carbonatesolutionrepeatedly.Whitecrystals

（1）

wereobtainedafterrecrystallizationinethanol

withan85%yield.Them.p.was205-208°

C.IR

（KBr,cm-1）:

3515,3445（N-H）,and1668（C=O）.

1HNMR（DMSO-d6,δ,ppm）:

3.82（s,6H,NH2）,

7.35-7.85（m,8H,Ar-H）,and10.12（s,2H,NH）.

2.3Synthesisof2,5-Bis（4-aminophenyl）-

1,3,4-oxadiazole

Thesynthesisof2,5-Bis（4-aminophenyl）-

1,3,4-oxadiazolewascarriedoutwithreferenceto

Qianetal.（2007）.Compound1（12.5g,0.047mol）

and150mlofphosphoruschlorideoxide（POCl3）

wereaddedtoaflaskandrefluxedfor8hundera

nitrogenatmosphere.Thiswasthencooledto

roomtemperature.Thereactionmixturewas

slowlypouredintoicewaterandneutralizedwith

adilutesodiumcarbonatesolution.Then,the

precipitatewasfilteredanddriedafterwashing

withwater.Compound2wasobtainedasbrown

needlecrystalsrecrystallizedfromchloroform/

methanol（1:

1）witha77.2%yield.Them.p.was

290-294°

C.Theanal.calcd.forC14H12ON4:

C,

66.65;

H,4.79;

andN,22.21.Found:

C,66.58;

H,

4.72;

andN,22.15.IR（KBr,cm-1）:

3525,3462

（N-H）,1542（C=N）,1452（N-N）,and1285

（C-O-C）.1HNMR（DMSO-d6,δppm）:

3.92（s,

6H,NH2）,and7.25-8.10（m,8H,Ar-H）.

2.4Tetrazotization2,5-Bis（4-aminophenyl）-

Compound2（2.52g,0.01mol）wassuspendedin

water（60ml）.Hydrochloricacid（3.8ml,0.03mol）

wasaddeddropwisetothiswellstirredsuspension.

31

Themixturewasgraduallyheatedupto70°

C,

untilaclearsolutionwasobtained.Thesolution

wascooledto0-5°

Cinanice-bath.Asolutionof

sodiumnitrate（NaNO2,0.7g）inwater（4ml）

previouslycooledto0°

C,wasthenaddedovera

periodof5minuteswithstirring.Thestirringwas

continuedforanhour,andthesametemperature

wasmaintained,withapositivetestfornitrous

acidonstarchiodidepaper.Afterdestroyingjust

theexcessivenitrousacidwiththerequired

amountofsulphamicacidsolution,acleartetrazo

solution3wasusedforthesubsequentcoupling

reactionat0-5°

C.

2.5CyanurationofH-acid（4a）

Cyanuricchloride（1.85g,0.01mol）wasstirredin

acetone（25ml）atatemperatureof0-5°

Cforan

hour.AneutralsolutionofH-acid（3.19g,0.01

mol）inanaqueoussodiumcarbonatesolution（10

%w/v）wasthenaddedinsmalllotsforaboutan

hour.ThepHwasmaintainedneutralby

simultaneousadditionofthesodiumcarbonate

solution（1%w/v）.Thereactionmasswasthen

stirredat0-5°

Cforanotherfourhours.Theclear

solutionofcyanuratedH-acidsolution4athus

formedwasusedforsubsequentcoupling

reactions.

Scheme1.Synthesisofdye5a

H2NCOOHNH2NH2

.H2O

H2N

NHNH

NH2

OO

（1）

PPA

POCl3Reflux

O

NN

（2）

NaNO2+HCl0-5oC

N

ClNNNCl

（3）

Couplingwith2moles

of（4a）

0-5oC

pH7.5to8.5

NNN

OHNH

NaO3SSO3Na

ClCl

NHOH

RR

（5a）

WhereR=Variouscyanuratedcouplingcomponents（4a-j）（Chart-1）

32

Scheme2.PreparationofcyanuratedH-acid（4a）

OHNH2

HO3SSO3H

Cl

+

pH7.0

（4a）

2.6SynthesisofReactiveDye（5a）

Toanice-coldandwell-stirredsolutionof

cyanuratedH-acid4a（4.67g,0.01mol）,afreshly

preparedsolutionoftetrazosolution3（1.26g,

0.005mol）wasaddeddropwiseoveraperiodof

10-15minutes.ThepHwasmaintainedat7.5to

8.5duringtheaddingofthesolution.Stirringwas

continuedfor3-4hours,andatemperaturebelow

5°

Cwasmaintained.Thereactionmixturewas

heatedupto60oCandsodiumchloride（12g）

addeduntilthecolouringmaterialwasprecipitated.

Itwasstirredforanhour,filteredandwashedwith

asmallamountofsodiumchloridesolution（5%

w/v）.Thesolidwasdriedat80-90oCandextracted

withdimethylformamide（DMF）.Thedyewas

precipitatedbydilu