Greener protocol for one pot synthesis of coumarin styryl dy(5)

S.B.Phadtareetal./DyesandPigments97(2013)105e112

Table2

Recyclabilityofdeepeutecticsolvent.Recycle

Fresh,Non-RecycledFirstSecondThird

Yield[%]78757572

109

e

dab

f

NCg1h

H

g2

H

b

a

c

H

h

H

i

7a

Fig.1.Chemicalstructureof7a.

ring);13CNMR(100MHz,CDCl3,TMS)d13.2,22.2,47.4,72.0,97.7,106.4,107.1,113.8,114.8,118.1,121.2,123.7,125.1,125.0,127.5,128.9,129.9,133.1,148.7,151.3,158.0,159.1,180.7;m/z(EI)488(Mþ1);Mol.Wt.:487.55;Anal.CalcdforC31H25N3O3:C,76.37;H,5.17;N,8.62.Found:C,76.17;H,5.26;N,8.72.

(E)-2-(1-(7-(Diethylamino)-2-oxo-2H-chromen-3-yl)-3-(furan-2-yl)allylidene)malononitrileTable1,7e:browncoloredsolid.Yield:1.7g(85%).Meltingpoint(measured)178e180 C;lmax(chloroform)/nm:409;nmax/cmÀ12975,2221,1703,1585,1514,1128,756;1HNMR(500MHz;CDCl3;TMS)1.27(6H,t,J¼7.0Hz(eCH3)2),3.47(4H,q,J¼7.0Hz(eCH2)2),6.54(1H,dd,J¼2.0Hz,furfuralring),6.56(1H,d,J¼2.5Hz),6.67(1H,dd,J¼9.0,2.5Hz),6.72(1H,d,J¼2.0Hz,furfuralring),6.88(1H,d,J¼15.5Hz,vinylproton),7.37(1H,d,J¼9.0Hz),7.42(1H,d,J¼15.5Hz,vinylproton),7.60(1H,d,J¼2.0Hz,furfuralring),7.66(1H,s,vinylproton,coumarinring);13CNMR(100MHz,CDCl3,TMS)d12.9,47.2,55.9,71.1,109.2,109.8,111.0,118.8,126.1,127.1,142.5,146.2,150.1,151.0,158.6,159.9,179.5;m/z(EI):386(Mþ1);Mol.Wt.:385.42;Anal.CalcdforC23H19N3O3:C,71.67;H,4.97;N,10.90.Found:C,71.47;H,4.82;N,10.92.

(E)-2-(1-(7-(Diethylamino)-2-oxo-2H-chromen-3-yl)-3-(pyr-idin-3-yl)allylidene)malononitrileTable1,7f:browncoloredsolid.Yield:1.8g(86%).Meltingpoint(measured)124e126 C;lmax(chloroform)/nm:488;nmax/cmÀ1:3400,2927,2221,1701,1577,1510,1245,800,703;1HNMR(500MHz;CDCl3;TMS)1.28(6H,t,J¼7.0Hz,(eCH3)2),3.52(4H,q,J¼7.0Hz,(eCH2)2),6.58(1H,d,J¼2.0Hz),6.69(1H,dd,J¼8.5,2.0Hz),7.14(1H,d,J¼16.5Hz,vinylproton),7.56(1H,d,J¼16.5Hz,vinylproton),7.98(1H,d,J¼8.0Hz,pyridyl),8.65(1H,dd,J¼8.0,2.02Hz,pyridyl),8.69(1H,d,

J¼2.0Hz,pyridyl);13CNMR(100MHz,CDCl3,TMS)d12.2,47.8,72.6,78.3,107.7,108.3,123.1,126.4,128.6,128.4,131.0,132.0,132.2,149.0,149.2,157.7,158.3,178.5;m/z(EI)397(Mþ1);Mol.Wt.:396.44;Anal.CalcdforC24H20N4O2:C,72.71;H,5.08;N,14.13.Found:C,72.51;H,5.18;N,14.03.

(E)-2-(1-(7-(Diethylamino)-2-oxo-2H-chromen-3-yl)-3-(9-ethyl-9H-carbazol-3-yl)allylidene)malononitrileTable1,7g:browncoloredsolid.Yield:2.1g(80).Meltingpoint(measured)decomposes>180 C;lmax(chloroform)/nm:472;nmax/cmÀ12926,2214,1712,1580,1494,1228,756;1HNMR(500MHz;CDCl3;TMS)1.27(6H,t,J¼7.0Hz,(eCH3)2),1.46(3H,t,J¼7.0Hz,(eCH3)),3.50(4H,q,J¼7.0Hz,(eCH2)2),4.41(2H,q,J¼7.0HzeCH2),6.58(1H,d,J¼2.6Hz),6.64-6.68(1H,dd,J¼6.5,2.5Hz),7.19e7.26(1H,d,J¼15.3Hz,vinylproton),7.30(1H,d,J¼7.0Hz),7.55e7.60(1H,d,J¼15.3Hz,vinylproton),7.72(1H,d,J¼2.0Hz),7.75(1H,d,J¼2.0Hz),8.01e8.03(1H,dd),8.10(1H,dd,J¼8.0,2.0Hz,8.24(1H,s);13CNMR(100MHz,CDCl3,TMS)d13.1,14.1,42.7,47.8,72.7,97.3,103.0,107.7,109.5,113.0,121.9,124.5,126.5,126.8,131.0,149.2,141.3,147.0,150.9,159.4,179.6;m/z(EI)513(Mþ1);Mol.Wt.:512.6;Anal.CalcdforC33H28N4O2:C,77.32;H,5.51;N,10.93.Found:C,77.12;H,5.41;N,10.99.

(E)-2-(1-(7-(Diethylamino)-2-oxo-2H-chromen-3-yl)-3-(4-(hexyl(phenyl)amino)phenyl)allylidene)malononitrile:Table1,7h:browncoloredsolid.Yield:2.41g(82%).Meltingpoint(measured)166e168 C;lmax(chloroform)/nm:526;nmax/cmÀ1:2952,2210,1718,1573,1503,1244,1172,823,698;1HNMR(300MHz;CDCl3;TMS):0.84(3H,t,J¼7.0Hz,(eCH3)),1.23e1.33(6H,m,(eCH2)3),1.59(2H,m,(eCH2)),1.27(6H,t,J¼7.0Hz,(eCH3)2),3.23(2H,t,J¼7.0Hz,(eCH2));3.43(4H,q,J¼7.0Hz(eCH2)2),6.68(1H,t,J¼7.9,1.8Hz),7.20e7.24(1H,d,J¼15.3Hz,vinylproton),7.57e7.62(1H,d,J¼15.3Hz,vinylproton),7.69(1H,s,vinylproton);13CNMR(100MHz,CDCl3,TMS)d12.5,14.1,22.3,27.6,31.6,47.2,49.8,71.6,97.5,106.4,109.7,112.1,113.1,125.7,127.1,128.8,132.1,134.1,149.5,152.7,156.1,159.9,178.7;m/z(EI):572(Mþ1);Mol.Wt.:570.72;Anal.CalcdforC37H38N4O2:C,77.87;H,6.71;N,9.82.Found:C,77.52;H,6.75;N,9.92.

3.Resultsanddiscussion

3.1.Synthesisofcoumarinderivatives

Afacileonepotcyclocondensationreactionofequimolarquantitiesof4-(diethylamino)-2-hydroxybenzaldehyde1,ethylacetoactetate2,malononitrile4andaromaticaldehydes6ae6hwascarriedoutinsequence,affordingstyryldyes7ae7h.TheschematicrepresentationisprovodedinScheme1.

Toinvestigatethescopeofthisonepotsynthesisdifferentaromaticaldehydeswereused,theresultsofwhicharelistedinTable1.Thereactionproceededsmoothlygiving71e86%yieldrequires3e6handshowed96e99%HPLCpurity.Acomparisonof

Table3

UVeVisabsorptionand uorescenceemissionmaximaof7ae7h(10À4M)invarioussolvents.Dyeno.

Toluene

Chloroform

Ethylacetate

Methanol

lmax(nm)

7a7b7c7d7e7f7g7h

370385458392411478475512

lem(nm)

422500538486469557550593

Stokesshift52115809458797581

lmax(nm)

376394484397409488472526

lem(nm)

430515558486465556557614

Stokesshift54121748956688588

lmax(nm)

380398495403413496492540

lem(nm)

448533585511495590594635

Stokesshift6813590108829410295

lmax(nm)

385403501412420515510555

lem(nm)

482548615515510625628660

Stokesshift9714511410390110118105