Letter - spectral assignment
Received: 29 June 2015
Revised: 11 September 2015
Accepted: 16 September 2015
Published online in Wiley Online Library: 14 October 2015
(wileyonlinelibrary.com) DOI 10.1002/mrc.4367
1
13
H and C NMR spectral assignments of 19
novel polymethoxylated
diphenylnaphthylpyrazolinylcarbothioamides
Hyeryoung Jung,a† Seunghyun Ahn,a† Yearam Jung,a Dongsoo Kohb*
and Yoongho Lima*
was added to compound (III, 5 mmol, 1.67 g) in 30 ml
anhydrous ethanol, and the solution was refluxed at 90 °C for
Introduction
Chalcones are secondary metabolites in plants produced via
the phenylpropanoid pathway.[1] Because 2-hydroxychalcones
(Fig. 1A) are known to show various biological activities includ-
ing anticancer and antioxidative effects, their derivatives have
been investigated and reported.[2,3] However, cyclization of 2-
hydroxychalcones results in the formation of flavanones.[4] As
such, the α,β-unsaturated carbonyl group was replaced with
a pyrazoline group (Fig. 1B). Diphenylpyrazolines contain a
C6-C3-C6 skeleton similar to chalcones, and they show more
biological activities including tyrosinase inhibition, antimicro-
bial effects, and monoamine oxidase inhibition.[5–7]
Diphenylpyrazolinyl-1-carbothioamdes (Fig. 1C) show dual in-
hibitory effects on monoamine oxidase and cholinesterase.[8]
Therefore, we designed phenyl-N-phenyl-naphthalenyl-
pyrazolinyl-1-carbothioamide (Fig. 1D) and synthesized 19 de-
rivatives. Pyrazolinyl-1-carbothioamdes are important because
of their diverse biological activities, and their NMR and mass
spectrometric (MS) data can aid in the identification of newly
synthesized or isolated derivatives in the future. Therefore,
we report herein the complete 1H and 13C NMR and high-
resolution MS data of 19 novel polymethoxylated
diphenylnaphthylpyrazolinyl-1-carbothioamides.
3 h. The reaction mixture was cooled to room temperature to
yield a solid that was then filtered. The crude solids were puri-
fied by recrystallization from ethanol to afford pure pyrazoline
(IV, mp; 191–194, yield; 43%). Phenylisothiocyanate (V, 68 mg,
0.5 mmol) and pyrazoline (IV, 174 mg, 0.5 mmol) were dissolved
in 15 ml of anhydrous ethanol, and the reaction mixture was
refluxed for 2 h. The resulting solid was filtered and purified
by recrystallized in ethanol to give a pure pyrazoline-
carbothioamide (11, mp; 230–232, yield; 70%). The other
pyrazoline-carbothioamides were prepared by the same
methods. The synthetic process is summarized in Scheme 1.[9]
NMR spectra
The
synthesized
polymethoxylated
diphenylnaphthyl-
pyrazolinyl-1-carbothioamides were dissolved in deuterated
dimethyl sulfoxide (DMSO-d6) and their concentrations were
adjusted to approximately 50 mM; the solutions were trans-
ferred to 2.5-mm NMR tubes. All NMR spectra were collected
using an Avance 400 spectrometer system (9.4 T; Bruker,
Karlsruhe, Germany) at 25 °C, and the chemical shifts were
referenced to TMS. The relaxation delay, 90° pulse, spectral
width, number of data points, and digital resolution in the
1H NMR experiments were 1 s, 11.8 μs, 5555 Hz, 32 K, and
0.339 Hz/point, respectively. The same parameters in the
13C NMR experiments were 3 s, 15.0 μs, 20,964 Hz, 64 K, and
0.640 Hz/point, respectively. Two-dimensional experiments in-
cluding correlation spectroscopy (COSY), heteronuclear multi-
ple quantum correlation (HMQC), and heteronuclear multiple
Experimental
Syntheses
Typical synthetic procedures are described to prepare com-
pound 11 as an example. To a solution of 4,6-dimethoxy-2-
hydroxyacetophenone (I, 10 mmol, 1.96 g) in 50 ml of ethanol
was added equivalent molar amount of 1-naphthaldehyde
(II, 10 mmol, 1.56 g), and the temperature was adjusted to
around at 0–4 °C in an ice-bath. To the cooled reaction
mixture was added 5 ml of 50 % (w/v) aqueous KOH solu-
tion, and reaction mixture was stirred at room temperature
for 24 h. This reaction was monitored using TLC. At the end
of the reaction, ice water was added to the mixture and
was acidified with 6 N HCl (pH = 3–4). The precipitate was
filtered and washed with water and ethanol. The crude
solid was purified by recrystallization from ethanol to give
pure chalcone compound (III, mp; 122–123, yield; 96%). Excess
hydrazine monohydrate (1 ml of 64–65% solution, 13 mmol)
*
Correspondence to: Yoongho Lim, Division of Bioscience and Biotechnology,
Konkuk University, Hwayang-Dong 1, Kwangjin-Ku, Seoul 143-701, Korea. E-mail:
** Correspondence to: Dongsoo Koh, Department of Applied Chemistry, Dongduk
Women’s University, Seoul 136-714, Korea. E-mail: dskoh@dongduk.ac.kr
†
H. Jung and S. Ahn contributed equally to this work.
a Division of Bioscience and Biotechnology, BMIC, Konkuk University, Seoul 143-701,
Korea
b Department of Applied Chemistry, Dongduk Women’s University, Seoul 136-714,
Korea
Magn. Reson. Chem. 2016, 54, 246–251
Copyright © 2015 John Wiley & Sons, Ltd.
Jung, Hyeryoung
