M. Jin, D. Jin, H. Wang et al.
Journal of Molecular Structure 1226 (2021) 129360
Scheme 1. Synthesis route of probe BSRH.
citation and emission slits set at 5.0 nm), respectively. High-
resolution mass spectra (HR-MS) were measured by a Brukermicro
TOF-QⅡ ESI-Q-TOF LC/MS/MS Spectrometer. 1H NMR and 13C NMR
spectra were recorded on a Varian INOVA-400 MHz spectrometer
using tetramethylsilane as internal standard. The cell line Hela was
obtained from Laboratory Center of the First Hospital of Jiaxing.
2.4. Synthesis of compound 4
To a suspended solution of compound 3 (1 mmol, 0.52 g) in
EtOH (30 mL) was added an excess of hydrazine monohydrate
(51.5 mmol, 2.0 mL, 80%) and the solution was refluxed for 6 h.
The resulting solution was evaporated in vacuum to give brownish
black oil, which was further by column chromatography (CH3OH
/ CH2Cl2 = 1 / 10) to afford compound 4 as a pale yellow solid
(0.386 g, yield: 72%). 1H NMR(Chloroform-d, 400 MHz): δ (ppm)
1.22 (t, J = 7.0 Hz, 6H), 3.38 (q, J = 7.1 Hz, 4H), 5.32 (s, 1H),
6.36 (dd, J = 8.9, 2.6 Hz, 1H), 6.47–6.50 (m, 2H), 6.94 (s, 1H),
6.98 (s, 1H), 7.15 (s, 1H), 7.18 (dd, J = 6.1, 2.5 Hz, 1H), 7.38 (t,
J = 7.6 Hz, 1H), 7.48 (t, J = 7.7 Hz, 1H), 7.53–58 (m, 2H), 7.75 (s,
1H), 7.81 (d, J = 8.0 Hz, 1H), 7.93 (d, J = 8.2 Hz, 1H), 8.03 (dd,
J = 6.3, 2.6 Hz, 1H). 13C NMR(DMSO–d6, 100 MHz): δ (ppm) 12.8,
29.4, 44.1, 85.6, 97.9, 103.0, 104.1, 105.0, 108.4, 109.4, 111.1, 112.3,
116.7, 122.2, 122.5, 123.7, 124.4, 125.2, 127.7, 129.6, 129.8, 131.9,
134.5, 135.0, 149.3, 150.7, 151.7, 152.6, 153.8, 154.7, 157.5, 159.9,
161.8, 163.3, 163.6. MS (ESI) m/z = 535.1798 [M + H]+, calc. for
C31H27N4O4S+ = 535.1840.
2.2. General procedure
The stock solution of probe 1 (1 mM) was prepared in MeOH.
The solutions of CuCl2 and other biologically relevant analytes
stock solutions (1 mM) were prepared in deionized water. The hy-
drochloride salts of Zn2+, Na+, K+, Ba2+, Ca2+, Cd2+, Sn4+, Mg2+
,
Co2+, Mn2+, Pb2+, Hg2+, Ni2+, Cr3+, Al3+, Fe2+, Fe3+, Cu2+ and the
nitrate salt of Ag+ ions were used to evaluate the properties of the
probe.
2.3. Synthesis of compound 3
The compound 2 was prepared from 2-aminothiophenol and
2,4-dihydroxy- benzaldehyde . The compound 1 was prepared from
3-diethylaminophenol and o-phthalic anhydride according to the
literature procedures. [31]
2.5. Synthesis of probe BSRH
Compound 4 (1 mmol, 0.534 g) and 2,4-Dihydroxybenzaldehyde
(1.1 mmol, 0.152 g) were mixed in ethanol (25 mL) with addi-
tion of 2 drops of acetic acid. After refluxing for 24 h, the mix-
ture was cooled to room temperature and evaporated to give deep
yellow oil, which was further by column chromatography (CH3OH
/ CH2Cl2 = 1 / 10) to afford probe BSRH as a pale yellow pow-
der (0.457 g, yield: 70%). 1H NMR(DMSO–d6, 400 MHz): δ (ppm)
1.9 (t, J = 6.9 Hz, 6H), 3.35 (d, J = 7.0 Hz, 4H), 5.76 (s, 1H), 6.16
(d, J = 2.3 Hz, 1H), 6.25 (dd, J = 8.5, 2.2 Hz, 1H), 6.43–6.47 (m,
2H), 6.50 (d, J = 2.3 Hz, 1H), 6.97 (s, 1H), 7.16 (d, J = 8.5 Hz, 1H),
7.22–7.24 (m, 1H), 7.37 (d, J = 7.6 Hz, 1H), 7.43 (d, J = 7.8 Hz, 1H),
7.63 (s, 1H), 7.65–7.67 (m, 1H), 7.93 (d, J = 8.2 Hz, 1H), 7.99–8.01
(m, 1H), 8.04 (d, J = 7.9 Hz, 1H), 9.15 (s, 1H), 9.97 (s, 1H), 10.42
(s, 1H), 11.88 (s, 1H). 13C NMR(DMSO–d6, 100 MHz): δ (ppm) 12.8,
39.5, 44.1, 55.3, 65.6, 98.0, 103.7, 104.3, 109.5, 111.1, 117.1, 122.2,
122.6, 124.6, 125.3, 126.7, 126.9, 127.5, 128.0, 130.2, 135.2, 136.3,
142.8, 149.5, 151.6, 152.1, 154.1, 157.8, 162.9, 165.3, 192.4. MS (ESI)
m/z = 655.2010 [M + H]+, calc. for C38H31N4O5S+ = 655.1942.
A suspension of 1 (0.243 g, 1 mmol) and 2 (0.313 g, 1 mmol)
in methanesulfonic acid (20 mL) was stirred at 90 ◦C for 24 h.
The reaction mixture was cooled to room temperature and then
poured in ice-cold water (100 mL). The precipitate was filtered,
washed with water (100 mL), and then dried under vacuum to
give the crude product, which was further by column chromatog-
raphy (CH3OH / CH2Cl2 = 1 / 15) to afford compound 3 as a pur-
ple solid (0.256 g, yield: 49%). 1H NMR(Chloroform-d, 400 MHz):
δ (ppm) 1.22 (t, J = 7.0 Hz, 6H), 3.40 (q, J = 7.1 Hz, 4H), 5.32
(s, 1H), 6.33–6.71 (m, 3H), 6.95 (s, 1H), 7.07 (s, 1H), 7.29 (d,
J = 3.0 Hz, 1H), 7.37 (t, J = 7.6 Hz, 1H), 7.47–7.51 (m, 1H), 7.67–
7.74 (m, 2H), 7.80 (d, J = 7.9 Hz, 1H), 7.96 (d, J = 8.1 Hz, 1H),
8.10–8.13 (m, 1H). 13C NMR(Chloroform-d, 100 MHz): δ (ppm) 12.5,
44.4, 65.4, 98.3, 104.8, 108.8, 114.1, 121.4, 121.9, 123.3, 123.8, 125.5,
126.7, 127.8, 128.7, 129.8, 132.3, 132.9, 150.9, 151.6, 153.3, 155.8,
159.1, 166.3, 168.3. MS (ESI) m/z = 521.1605 [M + H]+, calc. for
C31H25N2O4S+ = 521.1530.
2