J. Tian, K. Lu, Y. Wang et al.
Tetrahedron 95 (2021) 132366
TOF mass spectrometer, respectively. Fluorescence spectra were
obtained by using Hitech F-7000 spectrofluorometer at 298 K.
UVeVis absorption spectra were recorded on a Hitachi U1900
J ¼ 8.2 Hz, 1H), 7.59 (ddd, J ¼ 8.1, 6.1, 1.9 Hz, 1H), 7.46 (dd, J ¼ 9.1,
3.4 Hz, 1H), 7.38e7.31 (m, 3H), 7.24 (t, J ¼ 7.7 Hz, 1H), 6.98 (d,
J ¼ 8.5 Hz, 1H), 4.16 (m, 3H), 3.85e3.51 (m, 26H), 3.47 (m, 4H), 3.38
(d, J ¼ 1.7 Hz, 1H), 3.29e2.99 (m, 5H). 13C NMR (100 MHz, CDCl3)
spectrometer. Fluorescence quantum yield (F) was determined by
using Horiba Fluorolog-3.
d
193.0, 154.5, 141.9, 136.3, 134.5, 132.8, 132.2, 130.7, 129.8, 128.8,
Synthesis and Characterization of 8. A mixture of 7 (600 mg,
1.5 mmol) and NaHCO3 (310 mg, 3.7 mmol, 2.5 equiv) in DMSO
(20 mL) was heated at 90 ꢂC for 6 h under nitrogen. After the re-
action was complete, it was cooled to room temperature, and the
mixture was extracted with CH2Cl2. The organic extracts were
washed with H2O. The combined organic extracts were dried with
Na2SO4 and the solvent was removed under reduced pressure.
Then, the residue was dissolved in CH2Cl2/EtOH (10 mL/10 mL) and
concentrated hydrochloric acid (3 mL) was added. After heated at
reflux for 2 h, the reaction mixture was poured into H2O (20 mL) at
rt and neutralized with saturated NaHCO3 solution until no gas was
evolved. It was then extracted with EtOAc (2 ꢀ 20 mL) and
concentrated under reduced pressure to give 8 as a light yellow
128.4, 128.3, 128.1, 127.3, 127.2, 126.9, 125.1, 124.0, 122.1, 117.6, 114.1,
77.4, 72.7, 71.9, 70.7, 70.5, 70.5, 70.5, 70.4, 70.4, 70.3, 70.3, 70.2, 70.2,
70.1, 69.3, 69.3, 69.2, 69.2, 68.6, 61.6, 59.1, 29.7. HRMS: m/z calcd. for
C
40H52O11 M þ Na þ:731,3407. Found: 731,3405.
Synthesis and Characterization of 5c. A procedure similar to
the preparation of 5a was used by reacting I(CH2)3C8F17 with 8.
Compound 5c was obtained as a pale-yellow oil in 95 % yield
(241 mg). 1H NMR (400 MHz, CDCl3)
d 9.68 (s, 1H), 8.15 (d,
J ¼ 8.6 Hz, 1H), 8.05 (d, J ¼ 9.1 Hz, 1H), 8.01 (d, J ¼ 8.6 Hz, 1H), 7.93
(dd, J ¼ 12.9, 8.2 Hz, 2H), 7.57 (ddd, J ¼ 8.2, 6.0, 1.9 Hz, 1H),
7.43e7.35 (m, 2H), 7.33e7.24 (m, 3H), 7.07 (d, J ¼ 8.5 Hz, 1H), 4.10
(dt, J ¼ 9.2, 5.4 Hz, 1H), 3.96 (m, 1H), 1.69 (m, 2H), 1.51e1.34 (m, 2H).
13C NMR (100 MHz, CDCl3)
d 192.9, 154.0, 141.5, 136.4, 134.5, 132.6,
solid in 71 % yield. 1H NMR (400 MHz, CDCl3)
d
9.66 (s, 1H), 8.18 (d,
132.2, 130.8, 129.0, 128.8, 128.6, 128.4, 128.1, 127.4, 126.9, 126.8,
125.2, 124.3, 122.1, 118.3, 114.0, 67.5, 27.3, 27.0, 26.8, 20.4, 1.02.
J ¼ 8.6 Hz, 1H), 8.08 (d, J ¼ 8.6 Hz, 1H), 7.98 (dd, J ¼ 8.6, 6.9 Hz, 2H),
7.90e7.87 (m, 1H), 7.64 (ddd, J ¼ 8.2, 6.6, 1.4 Hz, 1H), 7.44 (ddd,
J ¼ 8.6,1.5, 0.8 Hz,1H), 7.41e7.30 (m, 3H), 7.27e7.22 (m,1H), 6.93 (d,
HRMS: m/z calcd. for
Found:781.1007.
C
32H19F17O2:
M
þ Na þ:781.1011.
J ¼ 8.4 Hz,1H), 4.87 (s,1H). 13C NMR (100 MHz, CDCl3)
d
192.3,151.6,
Sample preparation for fluorescence measurement. A stock
solution (2.0 mM) of a probe in various solvents was prepared.
Stock solutions (10.0 mM) of the TBA salts of amino acids were
prepared by mixing amino acids and TBAOH in methanol or water
138.7, 136.7, 134.4, 133.2, 132.6, 131.0, 129.8, 129.5, 128.8, 128.6,
128.2, 127.8, 127.4, 126.8, 124.6, 123.9, 122.6, 117.5, 113.6. HRMS: m/z
calcd. for C21H14O2 M þ Na þ:321.0891. Found:321.0886.
Synthesis and Characterization of 5a. Compound 8 (100 mg,
0.34 mmol) and K2CO3 (93 mg, 0.67 mmol, 2 equiv) were mixed in
MeCN (20 mL) at rt. EtBr (73 mg, 0.67 mmol, 2 equiv) was added
and the resulting mixture was heated at reflux for 24 h. EtOAc
(3 ꢀ 30 mL) was then used for extraction at rt. The organic extracts
were washed with water and dried with Na2SO4. The solvent was
removed under reduced pressure and the residue was purified by
flash column chromatography on silica gel (eluted with ethyl ace-
tate/petroleum ether,1:20) to afford 5a as a white solid in 97 % yield
in situ. For optical analysis, solutions of a probe (25 mL each) were
added to several test tubes. A solution of a TBA salt of an amino acid
was added to each test tube. The resulting solution was allowed to
stand at 308 K. After 3 h, the mixture in each test tube was diluted
with methanol to obtain 2.0 ꢀ 10ꢁ5 M solutions of the probe for
fluorescence measurements. Fluorescence spectra were recorded
within 1 h of the sample preparation.
Declaration of competing interest
(105 mg). m.p. 116e117 ꢂC. 1H NMR (400 MHz, CDCl3)
d 9.67 (d,
J ¼ 0.9 Hz, 1H), 8.14 (d, J ¼ 8.6 Hz, 1H), 8.01 (t, J ¼ 9.4 Hz, 2H), 7.94
(dd, J ¼ 8.2, 1.1 Hz, 1H), 7.88 (dd, J ¼ 8.2, 1.2 Hz, 1H), 7.57 (ddd,
J ¼ 8.2, 6.3, 1.7 Hz, 1H), 7.42 (d, J ¼ 9.1 Hz, 1H), 7.35e7.27 (m, 3H),
7.21 (ddd, J ¼ 8.2, 6.8, 1.3 Hz, 1H), 6.94 (dt, J ¼ 8.6, 0.9 Hz, 1H), 4.05
The authors declare that they have no known competing
financial interests or personal relationships that could have
appeared to influence the work reported in this paper.
(m, 2H), 1.03 (t, J ¼ 6.9 Hz, 3H). 13C NMR (100 MHz, CDCl3)
d 193.2,
Acknowledgement
154.5, 142.1, 136.4, 134.6, 132.8, 132.1, 130.6, 128.7, 128.7, 128.4,
128.3, 128.0, 127.3, 127.1, 126.7, 125.2, 123.9, 122.2, 117.6, 114.1, 64.6,
This work was financially supported by Sichuan Science and
Technology Program 2021YJ0398. LP thanks partial support of this
project by the US National Science Foundation (CHE-1855443).
14.8. HRMS: m/z calcd. for
Found:327.1387.
C
23H28O2
M
þ Hþ:327.1385.
Synthesis and Characterization of 5b. (a) Preparation of the
tosylate of CH3(OCH2CH2)9OH (15). Compound 15 [26] (2.14 g,
5 mmol) and dry triethylamine (1.05 mL, 7.5 mmol) were dissolved
in dry CH2Cl2 (60 mL) and p-toluenesulfonyl chloride (1.14 g,
6 mmol) was added. The reaction was stirred at rt for 20 h. The final
mixture was washed with sat. aq. NaHCO3, dried with anhydrous
Na2SO4 and concentrated under vacuum. The residue was purified
by column chromatography on silica gel (eluted with ethyl acetate)
to afford CH3(OCH2CH2)9OTs (16) as a pale-yellow oil in 95 % yield
(2.76 g). 1H NMR (400 MHz, Chloroform-d) 1H NMR (400 MHz,
Appendix A. Supplementary data
Supplementary data to this article can be found online at
References
Chloroform-d)
(td, J ¼ 4.8,1.7 Hz, 2H), 3.85e3.44 (m, 35H), 3.38 (s, 2H), 2.45 (s, 3H).
13C NMR (100 MHz, Chloroform-d)
144.82, 144.81, 132.78, 132.77,
d
7.80 (d, J ¼ 8.2 Hz, 2H), 7.35 (d, J ¼ 8.0 Hz, 2H), 4.16
d
129.82, 127.94, 72.67, 71.83, 70.64, 70.56, 70.49, 70.46, 70.41, 70.36,
70.05, 69.32, 69.25, 68.59, 61.54, 59.01, 21.64. HRMS: m/z calcd. for
C
26H24O12 S Mþ Na þ:605.2608. Found:605.2583. (b) A procedure
similar to the preparation of 5a was used by reacting 16 with 8
which gave compound 5b as a pale-yellow oil in 91 % yield
(215 mg). 1H NMR (400 MHz, CDCl3)
d
9.67 (s,1H), 8.14 (d, J ¼ 8.6 Hz,
1H), 8.03 (dd, J ¼ 16.2, 8.9 Hz, 2H), 7.96 (d, J ¼ 8.2 Hz, 1H), 7.90 (d,
8