H. Yoon et al.
99%; UV/VIS lmax (in acetonitrile): 367 nm; IR (cmꢁ1): 1326 (CS),
1509 (CN), 3317 (NH); HRMS (m/z): calcd. for C28H26N3O3S
(M+H)+ : 484.1695; found 484.1678.
N-(2,4-dimethoxyphenyl)-3-(1-hydroxynaphthalen-2-yl)-5-
(4-methoxyphenyl)-pyrazoline-1-carbothioamide (17) : mp 223
to 225 ꢀC; purity: 97%; UV/VIS lmax (in acetonitrile): 367 nm; IR
(cmꢁ1): 1372 (CS), 1532 (CN), 3355 (NH); HRMS (m/z): calcd. for
C29H28N3O4S (M+H)+ : 514.1801; found 514.1759.
HMQC, and HMBC, all data points (t2 ꢂ t1) were acquired with
2 Kꢂ 256.[14] The long-range delay for HMBC was 70 ms. The
mixing time for the NOESY experiment was 1 s. Zero-filling of
2 K and the sine-squared bell window function were applied
before Fourier transformation using XWin-NMR (Bruker).[14] All
NMR data were analyzed using Sparky.[15]
3-(1-hydroxynaphthalen-2-yl)-5-(4-methoxyphenyl)-N-(3,4,5-
trimethoxyphenyl)-pyrazoline-1-carbothioam\ide (18) : mp 177
to 180 ꢀC; purity: 98%; UV/VIS lmax (in acetonitrile): 367 nm; IR
(cmꢁ1): 1393 (CS), 1509 (CN), 3316 (NH); HRMS (m/z): calcd. for
General experimental procedures
To confirm the structures of the 22 synthesized chalcone deriva-
tives, high-resolution mass spectrometry (HRMS) was performed
on an electrospray ionization and ion trap tandem mass spec-
trometer (Varian 500-MS equipment, Varian Inc., Palo Alto, CA)
for derivatives 1 to 20, and on a high-resolution electron impact
ionization mass spectrometer (JMS700; JEOL Ltd., Tokyo, Japan)
with the help of the Korea Basic Science Institute at Daegu, Korea
for derivatives 21 to 22. Ultraviolet/visible (UV/VIS) spectra and IR
spectra were collected on a 50 Conc UV-Visible spectrophotome-
ter (Varian) and FT-IR 4200 (JASCO, Easton, MD) with Attenuated
Total Reflection, ATR PR0450-S, respectively. Melting points were
measured using Mel-Temp II (LabX, Midland, ON, Canada).
C
30H30N3O5S (M+H)+ : 544.1906; found 544.1957.
3-(2-hydroxynaphthalen-1-yl)-5-(2-methoxyphenyl)-N-
phenyl-pyrazoline-1-carbothioamide (19) : mp 228 to 230ꢀC; purity:
99%; UV/VIS lmax (in acetonitrile): 346nm; IR (cmꢁ1): 1350 (CS),
1517 (CN), 3303 (NH); HRMS (m/z): calcd. for C27H24N3O2S (M+H)+
: 454.1589; found 454.1628.
3-(2-hydroxynaphthalen-1-yl)-5-(2-methoxyphenyl)-N-(4-
methoxyphenyl)-pyrazoline-1-carbothioamide (20) : mp 186 to
188 ꢀC; purity: 99%; UV/VIS lmax (in acetonitrile): 338 nm;
IR (cmꢁ1): 1350 (CS), 1523 (CN), 3312 (NH); HRMS (m/z): calcd.
for C28H26N3O3S (M+H)+ : 484.1695; found 484.1717.
3-(2-hydroxynaphthalen-1-yl)-N,5-bis(2-methoxyphenyl)-
pyrazoline-1-carbothioamide (21) : mp 200 to 202 ꢀC; purity: 98%;
UV/VIS lmax (in acetonitrile): 340 nm; IR (cmꢁ1): 1352 (CS), 1509
(CN), 3333 (NH); HRMS (m/z): calcd. for C28H26N3O3S (M+H)+
484.1695; found 484.1697.
:
Results and Discussion
3-(2-hydroxynaphthalen-1-yl)-5-(2-methoxyphenyl)-N-(3,4,5-
trimethoxyphenyl)-pyrazoline-1-carbothioamide (22) : mp 188
to 190 ꢀC; purity: 99%; UV/VIS lmax (in acetonitrile): 336 nm; IR
(cmꢁ1): 1367 (CS), 1506 (CN), 3326 (NH); HRMS (m/z): calcd. for
The structures and the names of the synthesized chalcones
bearing pyrazoline–carbothioamide groups are shown in Fig. 2.
All of these compounds are novel. The procedure used to de-
termine the structure of derivative 1 from its NMR data is as
follows. Twenty-five peaks were observed in the 13C NMR
spectrum of derivative 1. The most deshielded carbon at
173.7 ppm was identified as a thiocarbon (C-py-6). The signals
at 126.0 and 128.0 ppm had twice the intensity of neighboring
signals and were assigned to C-200/C-600 and C-300/C-500, respec-
tively. The HMQC and the COSY spectra revealed an N-phenyl
group. A signal at 55.5 ppm corresponded to 2-OMe, which
was directly correlated with the proton at 3.85 ppm in the
HMQC spectrum. This proton was long-range coupled to the
13C peak at 155.7 ppm in the HMBC spectrum, so it was
assigned to C-2. The proton and the carbon atoms of the 2-
methoxyphenyl group were assigned as described previously
for the N-phenyl group. The 1H peaks at 3.24 and 4.12 ppm
corresponded to protons directly attached to the 13C atom
given by the peak at 42.0 ppm. These were assigned the H-py-
4a and H-py-4b of pyrazoline and verified by long-range couplings
with C-1 in the HMBC spectrum. The protons and the carbon atoms
in pyrazoline were identified on the basis of assignments made
C
30H30N3O5S (M+H)+ : 544.1906; found 544.1909.
NMR spectra
Synthetic chalcones bearing pyrazoline–carbothioamide groups
were dissolved in deuterated dimethyl sulfoxide (DMSO-d6).
1
The H and 13C chemical shifts of the deuterated solvent were
2.50 and 39.5 ppm referenced to TMS, respectively. NMR
samples were prepared at approximately 50 mM and trans-
ferred to a ꢀ 2.5-mm NMR tube for spectral analysis. All NMR
experiments were carried out on an Avance 400 spectrometer
system (9.4 T; Bruker, Karlsruhe, Germany) at 25 ꢀC. For one-
1
dimensional (1D) H NMR spectra, the relaxation delay, 90ꢀ
pulse, spectral width, number of data points, and digital
resolution were 1 s, 11.8 ms, 5555 Hz, 32 K, and 0.17 Hz/point,
respectively. For 13C NMR spectra, the same parameters were
3 s, 15.0 ms, 20,964 Hz, 64 K, and 0.32 Hz/point, respectively. For
two-dimensional (2D) experiments such as COSY, NOESY,
Table 3. Comparison of chemical shifts depending on methoxy group position at C1 to C3 and hydroxyl group position at naphthalene ring.
(Unit: ppm)
Position
2-Methoxylated
3-Methoxylated
4-Methoxylated
1-Hydroxynaphthalenylated
2-Hydroxynaphthalenylated
derivatives 1–6
derivatives 7–12
derivatives 13–18
derivatives 1–18
derivatives 19–22
C-py-5
H-py-5
C-30
C-60
C-100
58.0–58.2
61.8–61.9
61.4–61.5
—
—
6.20–6.28
6.09–6.12
6.04–6.09
—
—
—
—
—
—
—
—
—
—
—
125.5–125.6
128.1–128.2
134.8–134.9
118.1–118.2
123.0–123.2
127.7–127.9
wileyonlinelibrary.com/journal/mrc
Copyright © 2013 John Wiley & Sons, Ltd.
Magn. Reson. Chem. (2013)
Yoon, Hyuk
