2
S. Li et al.
DMSO-d6): dH ¼ 9.89 (s, 1H), 8.86 (s, 1H), 8.59 (s, 1H),
8.39 (s, 1H), 8.05 (d, J ¼ 8.4 Hz, 1H), 7.67 (d, J ¼ 7.6 Hz,
1H), 7.53–7.23 (m, 7H), 7.09 (t, J ¼ 7.6 Hz, 1H), 5.31
(s, 2H); MS m/z 431.7 (M þ H)þ, calcd for C20H16Cl2-
N4O3 m/z ¼ 430.1.
Figure 1. Design strategy of aroylhydrazine-amide derivatives
as anion receptors.
1-(2-((6-Chloropyridin-3-yl)methoxy)benzoyl)-4-phenyl-
semicarbazide AR2. This compound was obtained through
methods referred above as white powder, yield 88%,
m.p. 219–221oC; IR (nmax, KBr, cm21): 3324.30 (NH),
1706.54, 1625.23 (NHC ¼ O); 1H NMR (400 MHz,
DMSO-d6): dH ¼ 9.90 (s, 1H), 8.70 (s, 1H), 8.59 (d,
4J ¼ 2 Hz, 1H), 8.31 (s, 1H), 8.06 (q, J ¼ 8 Hz, 1H), 7.67
(d, J ¼ 6 Hz, 1H), 7.53–7.41 (m, 4H), 7.26 (t, J ¼ 8 Hz,
3H), 7.07 (t, J ¼ 7.6 Hz, 1H), 6.96 (t, J ¼ 7.2 Hz, 1H),
5.32 (s, 2H); MS m/z 397.8 (M þ H)þ, calcd for
C20H17ClN4O3 m/z ¼ 396.1.
standard was TMS, d (parts per million) values were
reported as chemical shifts. Mass spectra were recorded on
a MicroMass Quattro microTM API instrument. All
solvents and reagents were analytical reagent and used
directly without further purification.
Syntheses of target molecules AR1–4
General synthetic procedure for 2-((6-chloropyridin-3-
yl)methoxy)benzohydrazide 4
To a solution of newly prepared methyl 2-((6-chloropyr-
idin-3-yl)methoxy)benzoate (5.55 g, 20 mmol) in EtOH
(5 mL), hydrazine hydrate (80%, 3.0 eq.) was added. The
resulting mixture was stirred at 60–70 8C for 5–7 h, and
TLC was used to monitor the reaction until the end. After
cooling the mixture to room temperature, the precipitates
were collected by filtration, washed with water and
recrystallised by ethanol. The compound 2-((6-chloropyr-
idin-3-yl)methoxy)benzohydrazide was obtained as a
white powder, yield 88%, m.p. 116–1188C, MS: 278.4
(C13H13ClN3Oþ2 , [M þ 1]þ).
1-(2-((6-Chloropyridin-3-yl)methoxy)benzoyl)-4-phe-
nylthiosemicarbazide AR3. This compound was obtained
through methods referred above as white powder, yield
94%, m.p. 197–198oC; IR (nmax, KBr, cm21): 3304.47
1
(NH), 1636.45 (NHC ¼ O), 1241.12 (C ¼ S); H NMR
(400 MHz, DMSO-d6): dH ¼ 10.19 (s, 1H), 9.91 (s, 1H),
9.39 (s, 1H), 8.60 (s, 1H), 8.03 (d, J ¼ 8 Hz, 1H), 7.86 (s,
1H), 7.58–7.28 (m, 7H), 7.17–7.08 (m, 2H), 5.35 (s, 2H);
MS m/z 413.7 (M þ H)þ, calcd for C20H17ClN4O2S
m/z ¼ 412.1.
General synthetic procedure for the target compounds
AR1–3
General synthetic procedure for the target compounds
AR4
The typical synthetic process of novel aroylhydrazinecar-
boxamide derivatives AR1–3 is shown as following: the
solution of appropriately substituted benzoylisocyanate or
isothiocyanate (2 mmol) in dry acetonitrile (5 mL) was
added dropwise to a stirred solution of 2-((6-chloropyr-
idin-3-yl)methoxy)benzohydrazide 4 (1.5 mmol) in dry
acetonitrile (15 mL). Then the reaction mixture was stirred
at 40–508C for 0.5–2 h, and was monitored by TLC till the
disappearance of compound 4. Finally, the reaction
solution was cooled to ambient temperature and the
precipitates were collected by filtration, washed with
acetonitrile and recrystallised by ethanol. Their physico-
chemical properties and the spectra data are as follows:
The typical synthetic process of novel aroylhydrazine-
oxoacetamide derivative AR4 is shown as following: The
mixture of 4-nitroaniline (3 mmol), oxalyl chloride (8 mL)
in toluene (5 mL) was heated at 60–70oC for 5 h. Excess
oxalyl chloride was removed in vacuo, and the residue oil
was directly treated with 2-((6-chloropyridin-3-
yl)methoxy)benzohydrazide 4 (1.5 mmol) in dry aceto-
nitrile (15 mL). Then the reaction mixture was stirred at
30–408C for about 1.5 h. TLC was used to monitor the
process of reaction until compound 4 disappear. The
ultimate mixture was cooled to ambient temperature and
the precipitates were collected by filtration, washed with
acetonitrile and recrystallised by ethanol. Their physico-
chemical properties and the spectra data are as follows:
1-(2-((6-Chloropyridin-3-yl)methoxy)benzoyl)-4-(4-chlor-
ophenyl)semicarbazide AR1. This compound was obtained
through methods referred above as white powder, yield
92%, m.p. 207–209oC; IR (nmax, KBr, cm21): 3335.51
(NH), 1712.15, 1658.88 (NHC ¼ O); 1H NMR (400 MHz,
2-(2-(2-((6-Chloropyridin-3-yl)methoxy)benzoyl)hydrazi-
nyl)-N-(4-nitrophenyl)-2-oxoacetamide AR4. This com-
pound was obtained through methods referred above as
white powder, yield 87%, m.p. 242–244oC; IR (nmax, KBr,