Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones: Synthesis, characterization, electrochemical behavior and antitumor activity

Article abstract of DOI:10.1590/s0103-50532010000100024

Novel 2-(R-phenyl)amino-3-(2-methyl-propenyl)-[1,4]-naphthoquinones (R = H, 4-OMe, 4-Ferrocenyl, 4-Me, 3-Me, 4-I, 3-I, 4-CN, 3-CN, 4-NO₂ and 3-NO₂) derived from nor-lapachol [2-hydroxy-3-(2-methylpropenyl)-1,4- naphthoquinone] were obtained in good yields. Their structures were proposed on the basis of a single crystal X-ray diffraction study (R = OMe, 2b), 1H and 13C NMR studies and calculations using the B3LYP functional and the 6-311+G(2d,p) basis set. The half-wave potentials of the aminonaphthoquinones and 1H NMR chemical shifts of the 3-propenyl hydrogen in 2a-k show good correlation with the substituent Hammett constants on the phenylamino ring. The antitumor assays showed promising activity for substrate methoxy-nor-lapachol 1 and the 4-ferrocenyl derivative 2c.

Full text of DOI:10.1590/s0103-50532010000100024

J. Braz. Chem. Soc., Vol. 21, No. 1, 169-178, 2010.
Printed in Brazil - ©2010 Sociedade Brasileira de Química
0103 - 5053 $6.00+0.00
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones: Synthesis,
Characterization, Electrochemical Behavior and Antitumor Activity
Acácio I. Francisco,a Annelise Casellato,a,# Amanda P. Neves,a J. Walkimar de M. Carneiro,a
Maria D. Vargas,*,a Lorenzo do C. Visentin,b Alviclér Magalhães,c Celso A. Câmara,d Claudia Pessoa,e
Letícia V. Costa-Lotufo,e José D. B. Marinho Filhoe and Manoel O. de Moraese
aInstituto de Química, Universidade Federal Fluminense, 24020-141 Niterói-RJ, Brazil
bInstituto de Química, Universidade Federal do Rio de Janeiro, 22640-000 Rio de Janeiro-RJ, Brazil
cInstituto de Química, Universidade Estadual de Campinas, 13083-970 Campinas-SP, Brazil
dInstituto de Química, Universidade Federal Rural de Pernambuco, 52171-900 Recife-PE, Brazil
eDepartamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, 60430-270 Fortaleza-CE, Brazil
Novas 2-(R-fenil)amino-3-(2-metilpropenil)-[1,4]-naftoquinonas (R = H, 4-OMe, 4-Ferrocenil,
4-Me, 3-Me, 4-I, 3-I, 4-CN, 3-CN, 4-NO2 e 3-NO2) derivadas do nor-lapachol [2-hidroxi-3-(2-
metilpropenil)-1,4-naftoquinona] foram obtidas em bons rendimentos. A estrutura dos compostos
foi proposta com base em estudos de difração de raios-X (R = OMe, 2b), dados de RMN de 1H
e 13Ce cálculos teóricos utilizando o funcional B3LYP e a base 6-311+G(2d,p). Os potenciais de
meia-onda das aminonaftoquinonas e o deslocamento químico do hidrogênio da cadeia 3-propenil
dos compostos 2a-k mostraram boa correlação com as constantes de Hammett dos substituintes
presentes no anel fenileno. A avaliação da citotoxicidade evidenciou atividade antitumoral
promissora para o substrato metóxi-nor-lapachol 1 e o derivado 4-ferrocenil 2c.
Novel 2-(R-phenyl)amino-3-(2-methyl-propenyl)-[1,4]-naphthoquinones (R = H, 4-OMe,
4-Ferrocenyl, 4-Me, 3-Me, 4-I, 3-I, 4-CN, 3-CN, 4-NO2 and 3-NO2) derived from nor-lapachol
[2-hydroxy-3-(2-methylpropenyl)-1,4-naphthoquinone] were obtained in good yields. Their
structures were proposed on the basis of a single crystal X-ray diffraction study (R = OMe, 2b),
1H and 13C NMR studies and calculations using the B3LYP functional and the 6-311+G(2d,p)
basis set. The half-wave potentials of the aminonaphthoquinones and 1H NMR chemical shifts of
the 3-propenyl hydrogen in 2a-k show good correlation with the substituent Hammett constants
on the phenylamino ring. The antitumor assays showed promising activity for substrate methoxy-
nor-lapachol 1 and the 4-ferrocenyl derivative 2c.
Keywords: Nor-lapachol, arylamine, aminonaphthoquinone, electrochemistry, B3LYP,
antitumor activity
Introduction
in quinones has led to interesting biologically active
compounds.7-12
Naphthoquinones are widely distributed in nature and
some of these molecules have an important role in the
biochemistry of microbial energy production, by means
of photosynthesis and respiratory chain.1 Compounds
containing the quinone group are known for exhibiting
antitumor,2 trypanocide,3 moluscicide,4 fungicide5 and
antimalarial6 activities. The presence of an amino group
Biological activity of quinones is often related to
their electrochemical behavior.13 The ability to accept
one or two electrons to form the corresponding radical
-
anion (Q• ) or dianion (Q2-) species is believed to induce
formation of reactive oxygen species, responsible for the
oxidative stress in cells.14 The electron-accepting capacity
of naphthoquinones may be tuned by carbonyl position
changes (1,2- x 1,4-naphthoquinones)15 or different
substituents or functions attached to the naphthoquinone
moiety, and the use of electrochemical methods to study
*e-mail: mdvargas@vm.uff.br
#Present address: Instituto de Química, Universidade Federal do Rio de
Janeiro, 22640-000 Rio de Janeiro-RJ, Brazil

170
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones
J. Braz. Chem. Soc.
this type of molecules has proven to be useful.16,17 We
reported recently18 the synthesis of a series of 2-arylamino-
1,4-naphthoquinones from 2-methoxy-1,4-naphthoquinone
in a pure state, whereas 2c-k were purified by column
chromatography using a mixture of ethyl acetate / hexane
(1:5) as eluent. They were obtained in yields ranging from
84 to 73% and formulated on the basis of analytical and
spectroscopic data (see Experimental).
•
and arylamines in the presence of MgCl2 6H2O and
p-toluenesulfonic acid as catalysts. The reactions of both
electron-donor and electron-attracting substituted anilines
having given good yields of the respective products, we
decided to investigate the analogous reactions of the
methoxy-derivatives of nor-lapachol [2-hydroxy-3-(2-
methyl-propenyl)-1,4-naphthoquinone]4 and lapachol
[2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone].19
Nor-lapachol is obtained from lapachol by the Hooker
oxidation20 and has been used as a substrate for the
synthesis of several active compounds.9-12 The incorporation
of polyamines to this quinone, for example, has led
to significant increase in the DNA topoisomerase II-a
inhibition, compared to the original naphthoquinone.13,14
Furthermore, arylamino derivatives of nor-a and nor-b
lapachones present potent antitumor11 and trypanocide
activities.9
Herein is the first report on the synthesis and
characterization of the novel 2-arylamine derivatives of nor-
lapachol 2a-k, including 2-(4-ferrocenyl-phenyl)amino-3-
(2-methylpropenyl)-1,4-naphthoquinone 2c (Figure 1) and
cytotoxic screening against the several cancer cell lines
(SF-295, HCT-8, MDAMB-435 and HL-60). Because
correlations between electrochemical potentials and the
inhibitory activity of naphthoquinones on Epstein-Barr
virus early antigen activation21 and their cytotoxicity22 has
been reported, we also investigated the redox properties of
these compounds by cyclic voltammetry.
The 1H NMR and infrared spectra of compounds 2a-k
are consistent with their composition and structure. The
1H NMR spectra exhibit signals in the d 7.5-8.2 ppm
region as double dublets and triple dublets, attributed to
the four naphthoquinone aromatic hydrogens H5-H8.
1
1
Attributions were made on the basis of H x H-COSY
experiments, J values and multiplicity. All expected
resonances were observed in the 13C NMR spectra of
compounds 2a-k. The carbonyl peaks appear around d 183
and 180, and those attributed to C2 bound to the nitrogen
at about d 145. The other chemical shifts are compatible
with the structures proposed for these compounds. We
observed that the chemical shift of H18 (Figure 2) in the
1H NMR spectra of 2a-k is directly influenced by the
nature of the R substituent group in the phenylamino ring
[5.80 (4-OMe) < dH(18) < 6.08 (4-NO2)].
14
R
15
16
13
12
O
11
2a (R=H)
2g (R=3-I)
NH
17
2b (R=4-OMe)
2c (R=4-Fc)
2d (R=4-Me)
2e (R=3-Me)
2f (R=4-I)
2h (R=4-CN)
2i (R=3-CN)
2j (R=4-NO2)
2k (R=3-NO2)
1
8
5
2
3
7
6
9
10
H(18)
4
19
O
20
21
Figure 2. Compounds 2a-k.
X-ray structure / Theoretical calculations
R
The structure of 2-(4-methoxy-phenyl)amino-3-(2-
methylpropenyl)-1,4-naphthoquinone 2b was determined
by a single crystal X-ray diffraction study (Figure 3). The
average C-C, C-O, C=O and C-N bond lengths are in good
agreement with the literature.36 The naphthoquinone ring
system of 2b is approximately planar, the dihedral angle
between the naphthoquinone plane and the arylamine
phenyl ring being 47.3°(1). The torsion angles around
the fragments involved in the H-bond are: C(2)-N(1)-
C(11)-C(12), -158.94(17)o, C(1)-C(2)-N(1)-C(11)
-154.47(16)o and N(1)-C(2)-C(1)-O(2) -3.2(2)°. The
planar unsaturated side chain is twisted about 54° with
respect to the ring system. This is the first reported structure
of an amine derivative of nor-lapachol.
NH2
O
O
NH
OMe
cat1 / cat2
+
MeOH, reflux
R
1
O
O
Figure 1. Synthesis of the novel arylamines derived from methoxy-nor-
lapachol 1.
Results and Discussion
Syntheses
The compounds 2a-k (Figure 2) were synthesized from
2-methoxy-3-(2-methylpropenyl)-[1,4]-naphthoquinone
with various aromatic amines, in the presence of the
catalysts 4-toluenesulfonic acid and MgCl2 6H2O in
methanol under reflux.18 The products are stable in the solid
The packing of 2b involves molecules that interact
through classical and non-classical hydrogen bonds,
forming a 1D infinite network along the crystallographic
[100] direction (Figures 4 and 5). The carbonyl O1i atom
•
state and in solution. Compounds 2a, 2b were obtained

Vol. 21, No. 1, 2010
Francisco et al.
171
makes a classical and a non-classical hydrogen bonds with
H1 to the N1 atom (amino group) and with H12 to the C12
atom (C11-C16 phenyl ring) of a neighboring molecule,
forming a six-membered ring [symmetry code: i = x-1, y, z].
In addition the other C=O group interacts via O2ii with
H5 to the C5 forming now a ten-membered ring. For more
details of the crystal structure, see Supplementary material.
Starting from the experimental structure of 2b
(Figure 3), the geometries of 2a-2e and 2h-2i were fully
optimized with the B3LYP/6-31G(d) method.37 Energies
and molecular properties were obtained from a single-
point calculation on the optimized geometries using the
6-311+G(2d,p) basis set38 and the B3LYP functional.39 To
confirm that the most stable conformation in the gas-phase
is similar to that found in the solid state the geometry of an
alternative conformation for 2b, with the 2-methylpropenyl
group bonded to position 3 of the naphthoquinone ring
rotated by 180o was also optimized. This alternative
conformation is 0.4 kcal mol-1 less stable than the solid
state conformation. The barrier for conversion between
the two conformers calculated at the 6-31G(d) level is
5.5 kcal mol-1.
Calculations of the absolute 1H NMR chemical shifts
using the GIAO approach40 confirmed that electron-
attracting groups yield higher dH(18) values than electron-
donor groups. Calculations including solvent (chloroform)
show essentially the same behavior. Interestingly, the
dH(18) value for the alternative conformation with the
2-methylpropenyl side chain rotated by 180o is shifted
highfield by 1.67 ppm, compared to the same hydrogen in
the most stable conformation. The fact that the experimental
values are intermediate between the calculated values for
the two conformations suggests that these conformations
are in equilibrium in solution, although the variable
temperature 1H NMR spectra of 2a do not show broadening
of H18 down to -90 oC in CD2Cl2.
Figure 3. View of the ORTEP plot for 2b with labeled atoms and 50% probability ellipsoids.
Figure 4. View of the intramolecular interaction.

172
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones
J. Braz. Chem. Soc.
Figure 5. View of the self-assembly 1D by classical and non-classical hydrogen bonds along the [100] crystallography direction. [Symmetry codes:
(i) x-1, y, z; (ii) x+1, y, z].
UV-Vis spectra
compound 2b. This was also observed for the Fc-arylamine
derivative of lawsone.18
TheUV-VisspectraofthecompoundsobtainedinCHCl3
show two absorption bands. PBE1PBE/6-311+G(2d,p)
calculations indicate that the band in the 275-290 nm
region can be attributed to the aromatic and quinone p-p*
transitions and the low-energy band in the visible region
between 456 and 512 nm is attributed predominantly to
p phenyl-p naphthoquinone transitions. Electron-donor
substituents blue shift the latter band, whereas electron-
attracting groups red shift it.
Table 1. Voltammetric data (V) for 2a-k vs FcH/FcH+ as internal standard
Compound
E1/2 (1)
-1.19
-1.23
-1.23
-1.20
-1.23
-1.17
-1.16
-1.10
-1.15
-
E1/2 (2)
E1/2 (1) – E1/2 (2)
2a
2b
2c
2d
2e
2f
0.35
0.36
-
-1.54
-1.59
-
*
0.38
0.27
0.40
0.32
0.37
0.38
-1.58
-1.50
-1.57
-1.48
-1.47
-1.53
-
2g
2h
2i
Cyclic voltammetry
2j
-
The redox behavior of compounds 2a-k was evaluated
by cyclic voltammetry (CV) at room temperature in
acetonitrile/Bu4NPF6 (0.1 mol L-1). The CVs were obtained
in the potential range from +1.3 to –2.1V vs FcH/FcH+ as
internal standard (Table 1). Two quasi-reversible pairs of
waves were observed for compounds 2a-i in the negative
region of the CV, which are attributed to the one-electron
transfer to the naphthoquinone moiety. The redox potentials
of the naphthoquinone unit are directly influenced by the
substituents in the phenylamino ring: electron-donor groups
present lower E1/2 when compared to electron-releasing
groups. The complexity of the CV observed for 2j indicated
that the nitro group is also electroactive in the cathodic
region studied41 and because the reduction potentials for the
nitro and the quinone moieties are similar, we were unable
to assess the voltammetric parameters for this derivative.
The data indicate that derivative 2c, R= ferrocenyl (Fc,
E1/2 = -1.23 V) exhibit electronic properties similar to
2k
0.47
-1.18
-1.65
Good correlation of the E1/2(1) potentials with the sp
and sp- Hammett constants42 was obtained (Figures 6 and 7,
respectively) except for the Fc group (Figure 7) for which
the low sp- value (-0.03)43 has been correlated to low
resonance contribution. The linear correlation coefficients
for both plots suggest that all naphthoquinones of this series
are reduced by the same mechanism. E1/2(1) potentials do
not show linear correlation with sm values.
Antitumor assays
The antitumor screening of compounds 2a-k was
carried out against three cancer cell lines: SF-295 (central
nervous system), HCT-8 (colon), MDAMB-435 (breast)
through an MTT assay35 and the results, summarized in the

Vol. 21, No. 1, 2010
Francisco et al.
173
of the solution, since this compound is slightly unstable in
solution in the presence of oxygen.
Experimental
Materials and methods
Reagents and solvents were used without further
purification. Microanalyses were performed using a Perkin-
Elmer CHN 2400 micro analyser at the Central Analítica,
Instituto de Química, USP-São Paulo, Brazil. Melting points
wereobtainedwithaMel-TempII, LaboratoryDevices-USA
apparatus and are uncorrected. IR spectra (KBr pellets)
were recorded on a FT-IR Spectrum One (Perkin Elmer)
spectrophotometer. 1H and 13C NMR spectra were recorded
with a Varian Unit Plus 300 MHz spectrometer in CDCl3;
coupling constants are reported in Hertz (Hz) and chemical
shifts in parts per million (ppm) relative to internal standard
Me4Si.Thehydrogensignalswereattributedthroughcoupling
constant values and 1H × 1H - COSY experiments. Electronic
spectra were taken on a Diode Array 8452A (Hewlett
Packard-HP) spectrophotometer using spectroscopic grade
solvents (Tedia Brazil) in 10-3 and 10-4 mol L-1 solutions.
Cyclic voltammograms were obtained on an Epsilon-BAS
potentiostat-galvanostat from 1 × 10-3 mol L-1 solutions
in chloroform containing 0.1 mol L-1 of TBABF4 as
supporting electrolyte, at room temperature and under
argon atmosphere. A standard three component system was
used: a carbon-glassy working electrode, a platinum wire
auxiliary electrode, and anAg/AgCl reference electrode for
organic media. Ferrocene was used as an internal standard
(E1/2 0.40 V vs NHE). Density functional calculations
were carried out using the Gaussian03W molecular orbital
package.23 Geometries were fully optimized using the
B3LYP functional24 with the standard 6-31G(d) basis set25
Solvent effects (chloroform) were estimated by single-point
calculations on the gas-phase optimized geometries by mean
of the continuum solvation model using the conductor-like
polarisable continuum model26 (CPCM) at the same level.
NMR absolute chemical shifts were calculated using the
GIAO (Gauge IndependentAtomic Orbital) method with the
B3LYP/6-311+G(2d,p) approach on the B3LYP/6-31G(d)
optimized geometry. The electronic spectra were calculated
using the TD (Time Dependent) methodology available
in Gaussian. The PBE1PBE functional together with the
6-311+G(2d,p) basis set was employed.
Figure 6. Correlation between E1/2(1) and sp.
Figure 7. Correlation between E1/2(1) and sp-.
Supplementary information, show that the Fc-derivative
2c and the methoxy-substrate 1 presented significant
proliferation inhibition against MDA-MB435, higher than
the positive control doxorubicin (DOX). In a second set of
experiments, four cell lines were used for IC50 determination
of previously selected compounds (1 and 2c). Only methoxy-
nor-lapachol 1 was highly active against MDA-MB435
and moderately active against HL-60 and HCT-8 cell lines
(Table 2). The loss of activity of the ferrocenyl derivative 2c
may be due to decomposition during dilution and defreezing
Table 2. Cytotoxic activity expressed by IC50 in μg mL-1 of compounds
1, 2c and doxorubicin (DOX), with the respective confidence intervals
Compound
SF295
> 5
HCT-8
> 5
MDA-MB435
> 5
HL-60
> 5
2c
1
Synthesis of the compounds 2a-k
> 5
2.53
0.30
1.17
(1.38-4.66)
(0.14-0.64)
(0.59-2.32)
DOX
0.42
0.35-0.46
0.07
0.05-0.09
0.86
0.62-1.20
0.04
0.02-0.04
Compounds 2a-k were synthesized by the same
procedure we reported recently for the synthesis of

174
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones
J. Braz. Chem. Soc.
2-arylamine-1,4-naphthoquinones derived from 2-hydroxy-
1,4-naphthoquinone and were obtained in yields that
varied from 71% (2c) to 84% (2h).18 [2-methoxy-3-
(2-methylpropenyl)-[1,4]-naphthoquinone] (155 mg,
0.64 mmol) 1 in MeOH (6.00 mL) was heated under
reflux in the presence of 4-toluenesulfonic acid (17.2 mg,
2-(4-Ferrocenyl-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2c)
Yield: 71%. mp 125-126 oC. Anal. Calc. for
C30H25FeNO2: C 73.93; H 5.17; N 2.87%; found: C 73.84;
H 5.11; N 2.81%. 1H NMR (300 MHz, CDCl3): d8.16 (ddd,
1H, J 7.40, J 1.57, J 0.51 Hz), 8.13 (ddd, 1H, J 7.40, J 1.57,
J 0.51 Hz), 7.79 (td, 1H, J 7.40, J 7.40, J 1.57 Hz), 7.69
(td, 1H, J 7.40, J 7.40, J 0.51 Hz), 7.55 (dd, 2H, J 6.12, J
2.09 Hz), 7.17 (dd, 2H, J 6.12, J 2.09 Hz), 5.82 (m, 1H),
4.61 (dd, 2H, J 2.37, J 1.98 Hz), 4.31 (dd, 2H, J 2.37, J
1.98 Hz), 4.04 (s, 5H), 1.35 (d, 3H, J 1.61 Hz), 1.24 (d,
3H, J 1.47 Hz). 13C NMR (75 MHz, CDCl3): 184.1, 181.8,
155.8, 139.4, 138.1, 131.7, 133.5, 131.3, 130.2, 129.6,
125.8, 124.3, 118.2, 114.9, 114.5, 112.3, 69.2, 68.7, 66.3,
24.9, 19.8. IR (KBr) νmax/cm-1: 3281, 3098, 2880, 1670,
1599, 1571, 1108, 994. UV-Vis (CHCl3) λmax/nm: 294
(log ε 4.29), 510 (3.64).
•
0.1 mmol) and MgCl2 6H2O (20.3 mg, 0.1 mmol) as
catalysts for 10 min. to dissolve most of 1. After addition
of the respective arylamine (0.96 mmol), the reactions
were monitored by TLC (1:9 ethyl acetate/hexane)
and were stopped when 1 was no more observed. The
resulting solids were filtered, washed with water and cold
MeOH and dried under vacuum. The melting points and
elemental analysis data are indicative of pure compounds.
In contrast, the analogous reactions of methoxylapachol
under the same conditions yielded the corresponding 1-aza-
1,2-dihydro-5,10-anthraquinones in low yields described
previously.19
2-(4-Methyl-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2d)
2-(Phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2a)
Yield: 81%. mp 141-142 oC.Anal. Calc. for C21H19NO2:
C 79.47; H 6.03; N 4.41%; found: C 79.43; H 6.01; N
4.38%. 1H NMR (300 MHz, CDCl3): d8.13 (m, 2H), 7.74
(td, 1H, J 7.57, J 1.47 Hz), 7.66 (td, 1H, J 7.57, J 1.47
Hz), 7.05 (br d, 2H, J 8.06 Hz), 6.80 (br d, 2H, J 8.06 Hz),
5.85 (m, 1H), 2.34 (s, 3H), 1.40 (d, 3H J 1.47 Hz), 1.26 (d,
3H, J 1.22 Hz). 13C NMR (75 MHz, CDCl3): 182.1, 181.3,
157.4, 141.4, 137.5, 133.9, 132.9, 132.0, 131.0, 130.9,
125.6, 123.9, 119.1, 114.3, 114.1, 112.5, 49.3, 25.1, 20.8.
IR (KBr) νmax/cm-1: 3272, 3101, 3045, 2900, 1668, 1587,
1565. UV-Vis (CHCl3) λmax/nm: 286 (log ε 4.00), 505 (3.25).
Yield: 78%. mp 131-133 oC.Anal. Calc. for C20H17NO2:
C 79.14; H 5.47; N 4.67%; found: C 79.19; H 5.65; N
1
4.62%. H NMR (300 MHz, CDCl3): d 8.13 (ddd, 1H,
J 6.51, J 1.51, J 0.49 Hz), 8.10 (ddd, 1H, J 6.51, J 1.51,
J 0.49 Hz), 7.73 (td, 1H, J 6.51, J 6.51, J 1.51 Hz), 7.65
(td, 1H, J 6.51, J 6.51, J 1.51 Hz), 7.23 (br t, 1H, J 7.52
Hz), 7.07 (tt, 1H, J 7.52, J 2.05, J 1.13 Hz), 7.91 (m, 1H),
6.89 (dt, 1H, J 7.93, J 2.05, J 1.34 Hz), 5.87 (m, 1H), 1.38
(d, 3H, J 1.54 Hz), 1.24 (d, 3H, J 1.32 Hz). 13C NMR (75
MHz, CDCl3): d 188.2, 184.3, 140.2, 139.5, 137.9, 134.8,
133.6, 132.6, 130.8, 127.9, 126.7, 124.2, 120.1, 118.9,
117.0, 100.2, 25.6, 20.6. IR (KBr) νmax/cm-1: 3278, 3102,
3051, 2902, 1670, 1590, 1567. UV-Vis (CHCl3) λmax/nm:
290 (log ε 4.15), 463 (3.37).
2-(3-Methyl-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2e)
Yield: 84%. mp 151-152 oC.Anal. Calc. for C21H19NO2:
C 79.47; H 6.03; N 4.41%; found: C 80.01; H 6.03; N 4.53%.
1H NMR (300 MHz, CDCl3): d8.12 (m, 2H); 7.74 (td, 1H,
J 7.48, J 7.48, J 1.51 Hz), 7.66 (td, 1H, J 7.48, J 7.48, J
1.51 Hz), 7.70 (m, 2H); 7.06 (br d, 2H, J 8.30 Hz); 5.84
(m, 1H); 6.80 (br d, 2H, J 8.30 Hz); 2.34 (s, 3H); 1.40 (d,
1H, J 1.22 Hz); 1.26 (d, 1H, J 1.33 Hz. 13C NMR (75 MHz,
CDCl3): 181.9, 181.2, 157.3, 141.5, 137.2, 133.8, 133.5,
132.4, 131.9, 131.0, 130.5, 129.5, 125.3, 123.4, 118.9,
114.0, 113.8, 112.1, 50.3, 24.5, 20.3. IR (KBr) νmax/cm-1:
3277, 3106, 3049, 2906, 1669, 1588, 1570. UV-Vis (CHCl3)
2-(4-Methoxy-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2b)
Yield: 80%. mp 167-169 oC.Anal. Calc. for C21H19NO3:
C 75.66; H 5.74; N 4.20%; found: C 75.56; H 5.69; N
4.22%. 1H NMR (300 MHz, CDCl3): d8.10 (m, 2H), 7.72
(td, 1H, J 7.49, J 7.49, J 1.54 Hz), 7.63 (td, 1H, J 7.70, J
1.54 Hz), 5.80 (m, 1H), 6.85 (br d, 2H, J 9.25 Hz), 6.77
(br d, 2H, J 9.25 Hz), 3.80 (s, 3H), 1.40 (d, 3H, J 1.54
Hz), 1.25 (d, 3H, J 1.32 Hz). 13C NMR (75 MHz, CDCl3):
183.7, 182.9, 156.5, 140.4, 138.8, 134.4, 133.0, 132.1,
130.8, 130.4, 126.0, 124.5, 118.4, 115.4, 114.7, 112.9,
55.4, 25.3, 20.2. IR (KBr) νmax/cm-1: 3288, 3100, 3031,
2889, 1668, 1600, 1577. UV-Vis (CHCl3) λmax/nm: 289
(log ε 4.20), 511 (3.45).
λmax/nm: 287 (log ε 4.15), 507 (3.31).
2-(4-Iodo-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2f)
Yield: 73%. mp 111-112 oC.Anal. Calc. for C20H16INO2:
C 55.96; H 3.76; N 3.26%; found: C 55.91; H 3.71; N 3.24%.

Vol. 21, No. 1, 2010
Francisco et al.
175
1H NMR (300 MHz, CDCl3): d8.13 (dd, 1H, J 7.52, J 1.58
Hz), 8.10 (dd, 1H, J 7.52, J 1.39 Hz), 7.74 (td, 1H, J 7.52,
J 7.52, J 1.39 Hz), 7.66 (td, 1H, J 7.52, J 7.52, J 1.58 Hz),
7.54 (br d, 2H, J 8.71 Hz), 6.65 (br d, 2H, J 8.71 Hz), 5.90
(m, 1H), 1.47 (d, 3H, J 1.53 Hz), 1.24 (d, 3H, J 1.33 Hz).
13C NMR (75 MHz, CDCl3): 184.3, 183.0, 140.3, 139.8,
137.7, 136.8, 134.9, 133.4, 132.8, 130.7, 126.5, 124.6,
118.9, 117.7, 100.3, 87.2, 25.7, 20.8. IR (KBr) νmax/cm-1:
3327, 3065, 2994, 1664, 1594, 1566. UV-Vis (CHCl3)
182.4, 140.8, 138.7, 138.2, 134.7, 132.8, 132.7, 130.2,
128.3, 126.7, 126.5, 126.2, 126.0, 124.9, 118.4, 118.1,
111.5, 25.3, 20.5). IR (KBr) νmax/cm-1: 3281, 3081, 2970,
2925, 2218, 1661, 1591, 1564. UV-Vis (CHCl3) λmax/nm:
284 (log ε 4.02), 475 (3.19).
2-(4-Nitro-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2j)
Yield: 84%. mp 205-207 oC.Anal. Calc. for C20H16N2O4:
C 68.96; H 4.63; N 8.04%; found: C 68.86; H 4.55; N
8.03%. 1H NMR (300 MHz, CDCl3): d 8.14 (m, 4H), 7.87
(br s, 1H), 7.78 (td, 1H J 7.59, J 7.59, J 1.47 Hz), 7.71 (td,
1H, J 7.59, J 1.57 Hz), 6.91 (br d, 2H, J 9.08 Hz), 6.08
(m, 1H), 1.27 (d, 3H, J 1.17 Hz), 1.53 (d, 3H, J 1.43 Hz).
13C NMR (75 MHz, CDCl3): 184.0, 182.3, 143.4, 142.4,
141.4, 138.0, 134.7, 132.7, 132.9, 130.7, 126.6, 123.6,
120.4, 120.8, 118.3, 99.8, 25.6, 20.7. IR (KBr) νmax/cm-1:
3283, 3084, 2974, 2911, 1593, 1663, 1500, 1332. UV-Vis
(CHCl3) λmax/nm: 281 (log ε 4.37), 469 (3.63).
λ
max/nm: 290 (log ε 4.01), 460 (3.47).
2-(3-Iodo-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2g)
Yield: 75%. mp 117-118 oC.Anal Calc. for C20H16INO2:
C 55.96; H 3.76; N 3.26%; found: C 55.92; H 3.74; N
3.23%. 1H NMR (300 MHz, CDCl3): d8.11 (dd, 1H, J 7.61,
J 1.64 Hz), 8.08 (dd, 1H, J 7.61, J 1.45 Hz), 7.72 (td, 1H,
J 7.61, J 1.45 Hz), 7.63 (td, 1H, J 7.61, J 1.64 Hz), 7.40
(m, 1H), 6.90 (m, 3H), 5.89 (m, 1H), 1.44 (d, 3H, J 1.49
Hz), 1.23 (d, 3H, J 1.28 Hz). 13C NMR (75 MHz, CDCl3):
184.1, 182.9, 140.5, 140.1, 137.3, 136.1, 134.6, 133.1,
132.4, 130.1, 126.9, 126.3, 124.3, 123.2, 118.1, 116.9,
100.1, 87.1, 25.2, 20.5. IR (KBr) νmax/cm-1: 3331, 3069,
2998, 1664, 1595, 1568. UV-Vis (CHCl3) λmax/nm: 284
(log ε 4.30), 456 (3.40).
2-(3-Nitro-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2k)
Yield: 83%. mp 210-211 oC.Anal. Calc. for C20H16N2O4:
C 68.96; H 4.63; N 8.04%; found: C 68.49; H 4.66; N
1
8.01%. H NMR (300 MHz, CDCl3): d 8.15 (ddd, 1H, J
7.57, J 1.46, J 0.49 Hz), 8.13 (ddd, 1H, J 7.57, J 1.46, J
0.49 Hz), 7.91 (ddd, 1H, J 8.06, J 1.93, J 0.98 Hz), 7.82
(br s, 1H), 7.77 (td, 1H, J 7.57, J 7.57, J 1.46 Hz), 7.69
(td, 1H, J 7.57, J 1.46 Hz), 7.67 (br s, 1H), 7.40 (br t, 1H,
J 8.06 Hz), 7.21 (dd, 1H, J 8.06, J 1.95 Hz), 6.01 (m, 1H),
1.43 (d, 3H, J 1.46 Hz), 1.24 (d, 3H, J 0.98 Hz). 13C NMR
(75 MHz, CDCl3): 183.8, 182.4, 147.3, 141.1, 138.6, 134.7,
132.8, 132.7, 130.2, 128.1, 127.1, 126.5, 126.2, 118.7,
118.4, 117.9, 116.3, 25.4, 20.6). IR (KBr) νmax/cm-1: 3279,
3080, 2970, 2908, 1597, 1661, 1498, 1330. UV-Vis (CHCl3)
2-(4-Cyano-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2h)
Yield: 79%. mp 161-163 oC.Anal. Calc. for C21H16N2O2:
C 76.81; H 4.91; N 8.53%; found: C 76.79; H 4.87; N 8.50%.
1H NMR (300 MHz, CDCl3): d 8.14 (dd, 1H, J 1.59, J 7.46
Hz), 8.12 (dd, 1H, J 1.49, J 7.46 Hz), 7.77 (td, 1H, J 7.46, J
7.46, J 1.49 Hz), 7.70 (td, 1H, J 7.46 Hz, J 7.46, J 1.59 Hz),
7.52 (br d, 2H, J 8.58 Hz), 6.90 (br d, 2H, J 8.58 Hz), 6.03
(m, 1H), 1.50 (d, 3H, J 1.48 Hz), 1.24 (d, 3H, J 1.27 Hz). 13C
NMR (75 MHz, CDCl3): 184.4, 182.8, 141.9, 141.4, 138.6,
135.1, 133.2, 132.0, 130.7, 127.0, 126.7, 121.7, 120.3, 119.2,
118.8, 106.1, 100.3, 25.9, 21.0. IR (KBr) νmax/cm-1: 3282,
3079, 2972, 2927, 2218, 1664, 1594, 1567. UV-Vis (CHCl3)
λmax/nm: 275 (log ε 4.39), 470 (3.59).
X-ray crystallography
λ
max/nm: 290 (log ε 4.19), 471 (3.48).
The X-ray diffraction data for 2b were collected at
295 K from a Enraf-Nonius Kappa-CCD27 diffractometer
with graphite monochromatized Mo Ka radiation. The cell
parameters were obtained and refined using PHICHI28 and
EvalCCD29 programs. Intensities for (1) were corrected by
Lorentz polarization and absorption with the SADABS30
program. The structure was solved by SHELXS-97 Direct
Methods,29 and refined with SHELXL-97,32 contained
within the WinGX-32 crystallography program.33 The
positional parameters of the H atoms bonded to C atoms in
the phenyl rings were obtained geometrically, with the C-H
distances fixed in 0.93Å for Csp2, and refined as riding on
2-(3-Cyano-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2i)
Yield: 82%. mp 173-174 oC.Anal Calc. for C21H16N2O2:
C 76.81; H 4.91; N 8.53%; found: C 76.77; H 5.01; N
1
8.55%. H NMR (300 MHz, CDCl3): d 8.15 (ddd, 1H, J
5.25 Hz, J 1.60 Hz, J 0.46 Hz), 8.12 (ddd, 1H, J 5.25 Hz,
J 1.60 Hz, J 0.46 Hz), 7.76 (td, 1H, J 5.25, J 5.25, J 1.60
Hz), 7.69 (td, 1H, J 5.25, J 5.25, J 1.60 Hz), 7.34 (m, 2H),
7.11 (m, 2H), 5.95 (m, 1H), 1.47 (d, 3H, J 1.37 Hz), 1.25
(d, 3H, J 1.14 Hz). 13C NMR (75 MHz, CDCl3): 183.7,

176
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones
J. Braz. Chem. Soc.
their respective C atoms, with Uiso(H) = 1.2Ueq(Csp2). H
atoms bonded to C atoms in the methyl group were located
geometrically and with the C-H distances fixed at 0.96Å
for Csp3 and with Uiso(H) = 1.5Ueq(Csp3). The positional
parameters of atom H1 bonded to N1 was obtained from a
Fourier difference map and refined freely with an isotropic
displacement parameter; the distance for N1-H1 is 0.87(2).
X-ray data are listed inTable 3 and ORTEP-334 forWindows
was used to draw the Figures.
reduction of the yellow dye 3-(4,5-dimethyl-2-thiazol)-2,5-
phenyl-2H-tetrazolium bromide (MTT) to a blue formazan
product as described by Mosmann.35
Conclusions
The eleven novel aminonaphthoquinones 2a-k, obtained
from methoxy-nor-lapachol and various arylamines,
were synthesized in good yields and showed interesting
electrochemical behavior due to the nature of the substituents
in the phenylamino ring, presenting a good correlation with
Hammett parameter, which confirms that the reaction with
electron-donor or electron-attracting groups follow a single
mechanism. Unfortunately, becausethearylaminederivatives
of nor-lapachol were not active against the tested tumor
cells, correlation between structure, electrochemical data
and antitumor activity could not be attempted.
Table 3. Crystal data and structure refinement for compound 2b
Formula
C21H19O3N
Formula weight
333.37
Crystal system, space group
Crystal size / mm
Triclinic, P-1
0.30 × 0.20 × 0.15
Unit cell dimensions
a, b ,c /Å
a, b, g /o
a =7.8709(16)
b = 9.3748(19)
c = 12.117(2)
a = 86.11(3)°
b = 81.60(3)°
g = 78.26(3)°
Supplementary Information
Supplementary data associated with this paper are
available free of charge at http://jbcs.sbq.org.br, as a PDF
file and contain the results of the theoretical calculations,
crystallographic data, NMR spectra (1H and APT), cyclic
voltammograms and antitumor assays of compounds 2a-k.
Crystallographic data for the structural analysis of the
three complexes have been deposited with the Cambridge
Crystallographic Data Center, CCDC 734112. Copies of
this information may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge, CB2 1EZ, UK
(fax: +44 1233336 033; e-mail: deposit@ccdc.cam.ac.uk).
Volume / Å3
865.3(3)
Z, Calculated density / (g cm-3)
2 / 1.279
T / K
295
Absorption coefficient /mm-1
0.086
θ range
3.99 to 25.00
352
F(000)
Reflections collected / unique
Rint
10324 / 3023
0.0358
Max. and min. transmission
Data/ restraints / parameters
S
0.9873 and 0.9748
3023 / 0 / 232
1.027
Acknowledgments
R indexes (all data)
Largest diff. peak and hole / (e- Å-3)
R1 = 0.0430, wR2 = 0.1031
0.153 and -0.180
The authors thank Prof. A. V. Pinto and Dr. M. C. F. R.
Pinto for providing nor-lapachol and the Brazilian agencies
Conselho Nacional de Desenvolvimento Científico e
Tecnológico (CNPq) and Fundação de Amparo à Pesquisa
do Estado do Rio de Janeiro (FAPERJ) for financial support.
Pronex-FAPERJ (grant number E-26/171.512/2006) is
acknowledged. J. W. D. Carneiro, M. D. Vargas, A. P.
Neves and C. A. Camara are recipients of CNPq research
fellowships.A. I. Francisco andA. Casellato were benefited
with CAPES fellowships. We also thank the X-ray
diffraction laboratory (LDRX) of Universidade Federal
Fluminense for data collection.
Antitumor assays
The compounds (1-5 mg mL-1) were tested for
cytotoxic activity against four cancer cell lines: SF-295
(Central Nervous System), HCT-8 (colon), MDAMB-435
(breast) and HL-60 (human leukemia). All cell lines were
maintained in RPMI 1640 medium supplemented with
10% fetal bovine serum, 2 mmol L-1 glutamine, 100 U mL-1
penicillin, and 100 mg mL-1 streptomycin at 37 oC with 5%
CO2. Each compound was dissolved in DMSO and diluted
with water to obtain a concentration of 1 mg mL-1. They
were incubated with the cells for 72 h. The negative control
received the same amount of DMSO (0.5% in the highest
concentration). Doxorubicin (0.1-0.58 mg mL-1) was used
as a positive control. The cell viability was determined by
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J. Braz. Chem. Soc.
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M. W.; Gonzalez, C.; Pople, J. A.; Gaussian 03, Revision B.02,
Gaussian, Inc.: Pittsburg P. A., 2003.
31. Sheldrick, G. M.; SHELXS97; Program for Crystal Structure
Solution; University of Göttingen, Germany, 1997.
32. Sheldrick, G. M.; SHELXL97; Program for Crystal Structure
Refinement; University of Göttingen, Germany, 1997.
33. Farrugia, L. J.; J. Appl. Crystallogr. 1999, 32, 837.
34. Farrugia, L.J.; J. Appl. Crystallogr. 1997, 30, 565.
35. Mosmann, T.; J. Immunol. Methods 1983, 65, 55.
36. Larsen, I. K.;Andersen, L.A.; Acta Crystallogr., Sect. C: Cryst.
Struct. Commun. 1992, 48, 2009.
37. Rassalov, V. A.; Pople, J. A.; Ratner, M. A. Windus, T. L.;
J. Chem. Phys. 1998, 109, 1223.
38. McLean,A. D.; Chandler, G. S.; J. Chem. Phys. 1980, 72, 5639.
39. Becke, A. D.; J. Chem. Phys. 1992, 96, 2155.
40. Wolinski, K.; Hilton, J. F.; Pulay, P.; J. Am. Chem. Soc. 1990,
112, 8251.
24. Beck, A. D.; J. Chem. Phys. 1993, 98, 5648.
25. Hariharan, P. C.; Pople, J. A.; Theor. Chim. Acta 1973, 28, 213.
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2003, 24, 669.
41. Aguilar-Martínez, M.; Cuevas, C.; Jiménez-Estrada, M.;
González, I.; Lotina-Hennsen, B.; Macías-Ruvalcaba, N.;
J. Org. Chem. 1999, 64, 3684.
27. Nonius; COLLECT, Nonius BV: Delft, The Netherlands, 1998.
28. Duisenberg, A. J. M.; Hooft, R. W. W.; Schreurs, A. M. M.;
Kroon, J.; J. Appl. Crystallogr. 2000, 33, 893.
42. Hansch, C.; Leo, A.; Taft, R. W.; Chem. Rev. 1991, 91, 165.
43. Nesmeyanov,A. N.; Perevalova, E. G.; Gubin, S. P.; Grandberg,
K. I.; Kozlovsky, A. G.; Tetrahedron Lett. 1966, 7, 2381.
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Received: August 11, 2009
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Web Release Date: November 12, 2009
FAPESP helped in meeting the publication costs of this article.

J. Braz. Chem. Soc., Vol. 21, No. 1, S1-S18, 2010.
Printed in Brazil - ©2010 Sociedade Brasileira de Química
0103 - 5053 $6.00+0.00
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones: Synthesis,
Characterization, Electrochemical Behavior and Antitumor Activity
Acácio I. Francisco,a Annelise Casellato,a# Amanda P. Neves,a J. Walkimar de M. Carneiro,a
Maria D. Vargas,*,a Lorenzo do C. Visentin,b Alviclér Magalhães,c Celso A. Câmara,d Claudia Pessoa,e
Letícia V. Costa-Lotufo,e José D. B. Marinho Filhoe and Manoel O. de Moraese
aInstituto de Química, Universidade Federal Fluminense, 24020-141 Niterói-RJ, Brazil
bInstituto de Química, Universidade Federal do Rio de Janeiro, 22640-000 Rio de Janeiro-RJ, Brazil
cInstituto de Química, Universidade Estadual de Campinas, 13083-970 Campinas-SP, Brazil
dInstituto de Química, Universidade Federal Rural de Pernambuco, 52171-900 Recife-PE, Brazil
eDepartamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, 60430-270 Fortaleza-CE, Brazil
1. Theoretical Calculations
with the methoxy group rotated by 90o (entry 2b-2 in Table
S1) yielded essentially the same dH18 value as that obtained
for the most stable conformation. To verify the effect of
the solvent on the chemical shifts some calculations were
repeated with the solvent chloroform, using the CPCM
approach. These calculations revealed that the solvent has
only marginal influence on the relative chemical shifts.
The electronic spectra were calculated using the TD
(Time Dependent) methodology available in Gaussian.
The PBE1PBE functional together with the 6-311+G(2d,p)
basis set was employed. All calculations were carried out
with the G03W package of molecular orbital calculation.
Starting from the experimental structure for 2b (4-Me),
the geometries of 2a-2e and 2h-2i were fully optimized
with the B3LYP/6-31G(d) method. Energies and molecular
properties were obtained from a single-point calculation
using the 6-311+G(2d,p) basis set and the B3LYP
functional. To confirm that the most stable conformation in
the gas-phase is similar to that found in the solid state the
geometry of an alternative conformation for 2b, with the
2-methyl-propenyl group bonded to the position 3 of the
naphthoquinone ring rotated by 180o was also optimized.
This alternative conformation was found 0.4 kcal mol-1
less stable than the solid state conformation. The barrier
for conversion between the two conformers calculated at
the 6-31G(d) level is 5.5 kcal mol-1.
2. Crystallographic Data
2.1. Computing details
The orientation of the 2-phenylene ring is stabilized
by an intramolecular hydrogen bond with one carbonyl
group of the naphthoquinone ring and was, therefore, not
further investigated. NMR absolute chemical shifts were
calculated using the GIAO (Gauge Independent Atomic
Orbital) method with the B3LYP/6-311+G(2d,p) approach
on the B3LYP/6-31G(d) optimized geometry. Absolute
energies and GIAO nuclear magnetic shielding tensors for
H(18) are given in Table S1. Interestingly, the dH18 value for
the alternative conformation (with the 2-methyl-propenyl
group rotated by 180o, entry 2b-4 in Table S1) is 1.67 ppm
shifted highfield as compared to the same hydrogen in the
most stable conformation. Calculation for 2b on a geometry
Data collection: COLLECT (Nonius, 1998); cell
refinement: PHICHI (Duisenberg, 2000); data reduction:
EVALCCD (Duisenberg, 2003); program(s) used to solve
structure: SHELXS97 (Sheldrick, 1997); program(s) used
to refine structure: SHELXL97 (Sheldrick, 1997); molecular
graphics: ORTEP-3 forWindows (Farrugia, 1997); software
used to prepare material for publication: WinGX publication
routines (Farrugia, 1999).
2.2. Experiment X-ray diffraction
The X-ray diffraction data for (2b) were collected at
295 K from a Enraf-Nonius Kappa-CCD diffractometer
with graphite-monochromatized Mo Ka radiation. The cell
parameters were obtained and refined using PHICHI and
*e-mail: *e-mail: mdvargas@vm.uff.br
#Present address: Instituto de Química, Universidade Federal do Rio de
Janeiro, 22640-000 Rio de Janeiro-RJ, Brazil

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Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones
J. Braz. Chem. Soc.
Table S1. Absolute energies (Hartree) and GIAO nuclear magnetic shielding tensors (ppm) for compounds 2a-2e and 2h-2i. All calculations were carried
out on a optimized B3LYP/6-31G(d) geometry
Absolute energies / hartree
GIAO nuclear magnetic shielding tensors / ppm
Derivative
B3LYP/6-31+G(d,p)
B3LYP/6-311+G(2d,p)
B3LYP/6-31+G(d,p)a
B3LYP/6-311+G(2d,p)b
2a (H)
-977.62466
-1092.15228
-1092.14589
-1092.16808
-1092.16687
-1092.15346
-2627.17389
-
-
24.64
24.64
24.67
24.64
26.31
24.62
24.66
-
-
2b-1 (4-OMe)
2b-2 (4-OMe)c
2b-3 (4-OMe)d
2b-4 (4-OMe)e
2l (3-OMe)
2c (4-Fc)
2m (3-Fc)
2d (4-Me)
2e (3-Me)
2h-1 (4-CN)
2h-2 (4-CN)d
2i-1 (3-CN)
2i-2 (3-CN)d
-1092.40283
24.97
-
-
-
-
-
-
-1092.40399
-2627.55599
-2627.55562
-1017.17288
-1017.17322
-1070.11410
-
24.89
24.79
24.85
24.86
24.81
24.79
-
-1016.94536
-
24.60
-
-1069.87032
-1069.89020
-1069.86851
-1069.88800
24.50
24.46
24.54
24.49
-1070.11232
-
24.75
-
aAt this level, the absolute GIAO nuclear magnetic shielding of TMS is 32.09 ppm. bAt this level, the absolute GIAO nuclear magnetic shielding of TMS
d
is 31.82 ppm. c Conformation with the methoxy group rotated by 90o. Calculation with inclusion of solvent (CPCM, chloroform). The absolute GIAO
e
nuclear magnetic shielding of TMS at this level is 31.63 ppm Alternative conformation, with the 2-methyl-propenyl group rotated by 180o, including
solvent effect (chloroform).
EvalCCD programs. Intensities for (2b) were corrected
by Lorentz polarization and absorption with the SADABS
program. The structure was solved by SHELXS-97 Direct
Methods, and refined with SHELXL-97, contained within
the WinGX-32 crystallography program. The positional
parameters of the H atoms bonded to C atoms in the
phenyl rings were obtained geometrically, with the C-H
distances fixed in 0.93Å for Csp2, and refined as riding on
their respective C atoms, with Uiso(H) = 1.2Ueq(Csp2). H
atoms bonded to C atoms in the methyl group were located
geometrically and with the C-H distances fixed at 0.96Å
for Csp3 and with Uiso(H) = 1.5Ueq(Csp3). The positional
parameters of H(1) bonded to N(1) was obtained from a
Fourier difference map and refined freely with an isotropic
displacement parameter; the distance for N(1)-H(1) is
0.87(2). X-ray data are listed in Table S2.
Crystallographic Data Center, CCDC 734112. Copies of
this information may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge, CB2 1EZ, UK
(fax: +44 1233336 033; e-mail: deposit@ccdc.cam.ac.uk).
The packing of 2b involves molecules that interact intra-
and intermolecularly through classical and non-classic
hydrogen bonds, forming a 1D infinite network along the
[100] crystallographic direction (Figures S2 and S3). The
naphthoquinone carbonyl O1i interacts via classical and
non-classic hydrogen bonds with H(1) to N(1) (imine
group) and with H(12) to C(12) [C(11)-C(16) phenyl
ring] of a neighboring molecule forming a six membered
ring [symmetry code: i = x-1, y, z]. In addition the other
carbonyl group interacts via O2ii with H(5) to C(5) forming
a ten membered ring in association with N(1)-H(1)…O(1).
The H-bond geometric parameters are listed in Table S4.
Table S5 gathers the atomic coordinates and equivalent
isotropic displacement parameters.
Crystallographic data for the structural analysis of
compound 2b have been deposited with the Cambridge
Figure S1. View of the ORTEP plot for 2b with labeled atoms and 50%
probability ellipsoids.
Figure S2. View of the intramolecular interaction.

Vol. 21, No. 1, 2010
Francisco et al.
S3
Figure S3. View of the self-assembly 1D by classical and non classical hydrogen bonds along the [100] crystallography direction. [Symmetry codes:
(i) x-1, y, z; (ii) x+1, y, z].
Table S2. Crystal data and structure refinement for 2b.
Table S3. Geometric parameters for molecule 2b (Å, °)
Formula
C21H19O3N
333.37
Bonds distances
N(1)-C(11)
1.424(2)
formula weight
N(1)-C(2)
1.367(2)
1.234(2)
1.223(2)
1.378(2)
1.423(2)
1.480(2)
1.328(3)
1.502(3)
1.510(3)
crystal system, space group
Triclinic, P-1
0.30 x 0.20 x 0.15
7.8709(16)
9.3748(19)
12.117(2)
86.11(3)
81.60(3)
78.26(3)
865.3(3)
2
O(1)-C(4)
crystal size / mm
O(2)-C(1)
a /Å
b/Å
O(3)-C(14)
O(3)-C(17)
c/Å
C(3)-C(18)
a / (o)
β / (o)
γ / (o)
V / Å3
Z
C(19)-C(18)
C(19)-C(20)
C(19)-C(21)
Bond angles
C(2)-N(1)-C(11)
C(14)-O(3)-C(17)
O(1)-C(4)-C(3)
O(1)-C(4)-C(10)
O(2)-C(1)-C(9)
O(2)-C(1)-C(2)
C(19)-C(18)-C(3)
C(20)-C(19)-C(21)
129.43(15)
116.93(16)
120.81(16)
119.19(16)
121.52(16)
119.54(16)
126.38(17)
115.62(18)
T / K
295
ρ
calc. / (g cm-3)
1.279
μ / mm-1
0.086
2θ range
3.99 to 25.00
352
F(000)
Reflections collected
10324
Reflections unique
3023
Rint
0.0358
Table S4. Geometric parameters for non-classical H bonds for molecule
(2b) (Å, °)
Max. and min. transmission
0.9873 and 0.9748
3023 / 0 / 232
1.027
datab/restraints/parameters
D-H···A
D-H
0.87 (2)
0.87 (2)
0.93
H···A
2.18 (2)
2.46 (2)
2.58
D···A
∠D-H···A
Sb,c
N(1)—H(1) ···O(2)
N(1)—H(1) ···O(1)i
C(12)—H(12)···O(1)i
C(5)—H(5) ···O(2)ii
2.620 (2) 111.2 (18)
3.241 (2) 150.2 (18)
R1a,d
0.0430
wR2b,e
0.1031
3.246 (2)
3.304 (2)
129
169
largest difference peak and hole / (e Å-3)
0.153 and -0.180
0.93
2.39
aFo2 ≥ 2σ(Fo2). bFo2 ≥ 3σ(Fo2). cS = [Σw(Fo2 – Fc2)2/(n – p)]1/2. dR1 = Σ||Fo| -
|Fc||Σ|Fo|. ewR2 = [Σw(Fo2 – Fc2)2/Σw(Fo4)]1/2
[Symmetry codes: (i) x-1, y, z; (ii) x+1, y, z]

S4
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones
J. Braz. Chem. Soc.
Table S5. Atomic coordinates (× 104) and equivalent isotropic displacement parameters (A2 × 103) for (2b). U(eq) is defined as one third of the trace of
the orthogonalized Uij tensor
x
y
z
U(eq)
43(1)
52(1)
70(1)
54(1)
54(1)
33(1)
38(1)
36(1)
35(1)
57(1)
35(1)
36(1)
34(1)
x
y
z
U(eq)
34(1)
40(1)
39(1)
40(1)
44(1)
39(1)
43(1)
44(1)
43(1)
51(1)
51(1)
61(1)
C(19)
C(20)
C(21)
O(1)
O(2)
C(2)
N(1)
C(1)
C(9)
O(3)
C(10)
C(4)
C(3)
-974(2)
-2387(3)
-31(3)
-1627(2)
-494(2)
-2776(3)
-120(2)
1227(2)
-323(2)
-1001(2)
916(2)
5732(2)
5299(2)
4922(2)
7804(1)
9030(1)
8018(1)
7743(1)
8784(1)
9233(1)
6747(1)
8931(1)
8106(2)
7634(1)
C(11)
C(12)
C(18)
C(16)
C(8)
-4275(2)
-5544(2)
-559(2)
-2999(2)
-3498(2)
-4310(2)
-3008(2)
112(2)
-2456(2)
-2751(2)
-1641(2)
-3610(2)
2840(2)
-5325(2)
-5025(2)
2050(2)
-4176(2)
3166(2)
3565(2)
-7133(2)
7413(1)
6832(2)
6757(2)
7728(2)
9955(2)
6920(2)
7473(2)
9372(2)
6589(2)
10106(2)
10390(2)
6440(2)
1355(2)
-5563(2)
-3178(2)
-4432(2)
-3973(2)
-2800(2)
-4254(2)
-984(2)
-239(2)
-1409(2)
C(14)
C(15)
C(5)
1709(2)
-6772(1)
1312(2)
152(2)
C(13)
C(6)
-5574(2)
-601(3)
-2398(3)
-5788(3)
C(7)
C(17)
-604(2)
3. 1H NMR and APT Spectra (CDCl3) of Compounds 2a-k
Figure S4. 1H NMR spectrum of 2-(phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2a).

Vol. 21, No. 1, 2010
Francisco et al.
S5
Figure S5. APT spectrum of 2-(phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2a).
Figure S6. 1H NMR spectrum of 2-(4-methoxy-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2b).

S6
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones
J. Braz. Chem. Soc.
Figure S7. APT spectrum of 2-(4-methoxy-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2b).
Figure S8. 1H NMR spectrum of 2-(4-ferrocenyl-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2c).

Vol. 21, No. 1, 2010
Francisco et al.
S7
Figure S9. APT spectrum of 2-(4-ferrocenyl-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2c).
Figure S10. 1H NMR spectrum of 2-(4-methyl-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2d).

S8
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones
J. Braz. Chem. Soc.
Figure S11. APT spectrum of 2-(4-methylphenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2d).
Figure S12. 1H NMR spectrum of 2-(3-methylphenylene)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2e).

Vol. 21, No. 1, 2010
Francisco et al.
S9
Figure S13. APT spectrum of 2-(3-methyl-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2e).
Figure S14. 1H NMR spectrum of 2-(4-iodo-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2f).

S10
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones
J. Braz. Chem. Soc.
Figure S15. APT spectrum of 2-(4-iodo-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2f).
Figure S16. 1H NMR spectrum of 2-(3-iodo-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2g).

Vol. 21, No. 1, 2010
Francisco et al.
S11
Figure S17. APT spectrum of 2-(3-iodo-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2g).
Figure S18. 1H NMR spectrum of 2-(4-ciano-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2h).

S12
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones
J. Braz. Chem. Soc.
Figure S19. APT spectrum of 2-(4-ciano-phenyl)-3-(2-methylpropenyl)-1,4-naphthoquinone (2h).
Figure S20. 1H NMR spectrum of 2-(3-ciano-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2i).

Vol. 21, No. 1, 2010
Francisco et al.
S13
Figure S21. APT spectrum of 2-(3-ciano-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2i).
Figure S22. 1H NMR spectrum of 2-(4-nitro-phenylene)-3-(2-methylpropenyl)-1,4-naphthoquinone (2j).

S14
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones
J. Braz. Chem. Soc.
Figure S23. APT spectrum of 2-(4-nitro-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2j).
Figure S24. 1H NMR spectrum of 2-(3-nitro-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2k).

Vol. 21, No. 1, 2010
Francisco et al.
S15
Figure S25. APT spectrum of 2-(3-nitro-phenyl)amino-3-(2-methylpropenyl)-1,4-naphthoquinone (2k).
4. Variable Temperature 1H NMR Spectra of Compound 2a
Figure S26. VT 1H NMR spectra of compound 2a (range: 25oC to -90 oC) in CD2Cl2.

S16
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones
J. Braz. Chem. Soc.
4. Cyclic Voltammograms (100mV) of Compounds 2a-k
Figure S27. CV of 2-(phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2a).
Figure S30. CV of 2-(4-methyl-phenyl)amino-3-(2-methylpropenyl)-
1,4-naphthoquinone (2d).
Figure S31. CV of 2-(3-methyl-phenyl)amino-3-(2-methylpropenyl)-
1,4-naphthoquinone (2e).
Figure S28. CV of 2-(4-methoxy-phenyl)amino-3-(2-methylpropenyl)-
1,4-naphthoquinone (2b).
Figure S29. CV of 2-(4-ferrocenyl-phenyl)amino-3-(2-methylpropenyl)-
1,4-naphthoquinone (2c).
Figure S32. CV of 2-(4-iodo-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2f).

Vol. 21, No. 1, 2010
Francisco et al.
S17
Figure S33. CV of 2-(3-iodo-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2g).
Figure S36. CV of 2-(4-nitro-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2j).
Figure S34. CV of 2-(4-ciano-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2h).
Figure S37. CV of 2-(3-nitro-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2k).
Figure S35. CV of 2-(3-ciano-phenyl)amino-3-(2-methylpropenyl)-1,4-
naphthoquinone (2i).

S18
Novel 2-(R-phenyl)amino-3-(2-methylpropenyl)-[1,4]-naphthoquinones
J. Braz. Chem. Soc.
5. Antitumor Assays
nervous system), HCT-8 (colon), MDAMB-435 (breast)
through an MTT assayref and the results are summarized
in Table S6.
The antitumor screening of compounds 2a-k was
carried out against three cancer cell lines: SF-295 (central
Table S6. Screening of the cytotoxic activity (growth inhibition %) of compounds 2a-k and 1
Compounds
SF295
Average
68.20
-11.01
2.57
GI%
SD
HCT-8
Average
73.75
-2.95
5.45
GI%
SD
MDA-MB435
Average
54.20
GI%
SD
2a (H)
4.80
11.89
7.43
3.71
0.40
23.88
2.20
0.56
2.48
0.90
4.20
15.08
0.63
1.68
13.01
6.24
2.76
1.01
2.13
4.49
0.84
6.36
1.44
2.02
3.12
3.99
5.00
9.15
1.09
3.58
3.54
3.42
13.42
0.93
4.35
8.24
7.68
0.16
2.23
2b (4-OMe)
2c (4-Fc)
2d (4-Me)
2e (3-Me)
2f (4-I)
24.54
102.31
17.21
12.20
58.59
-4.93
2.49
12.33
71.52
10.29
15.92
2.65
43.86
-7.63
2g (3-I)
25.14
2h (4-CN)
2i (3-CN)
2j (4-NO2)
2k (3-NO2)
1
-5.79
-12.56
8.78
10.72
6.73
-20.51
-18.20
4.01
17.00
17.03
27.01
94.85
-7.40
41.09
96.19
106.05
95.38
DOX
DOX = positive control, doxorubicin.