Na]. For deprotection, N-Boc-calix Boc-6 (254 mg, 0.195 mmol) was
dissolved in dichloromethane (2 mL), and trifluoroacetic acid (2 mL)
was subsequently added. After stirring for 2 h, the solvent was re-
moved in an airstream. The crude product was dissolved in di-
chloromethane (20 mL) and washed three times with NaOH
126.4 (2CH), 132.8, 134.6, 147.9, 148.1, 152.6 (5Cq-Ar), 174.8 ppm
(C=O).
[Ba-5]
(
(
20 mL, 1m). The organic layer was dried over Na SO to give 6
2 4
1
H NMR (400 MHz, CDCl ): d=0.93 (s, 18H; tBu), 1.28 (s, 18H; tBu),
3
221 mg, quant.) without further purification as pale yellow solid.
3
4
.39–3.52 (m, 8H), 3.69–4.16 (m, 36H), 4.23–4.43 (m, 8H), 4.84 (s,
1
M.p. 139–1428C; H NMR (400 MHz, CDCl ): d=0.81 (s, 18H; tBu),
3
13
H; CO(CH )O), 6.88 (s, 4H; ArH), 7.22 ppm (s, 4H; ArH); C NMR
2
2
1
4
1
.32 (s, 18H; tBu), 2.79–2.94 (m, 8H; NCH ), 3.17 (d, J=12.3 Hz,
2
(
(
(
101 MHz, CDCl ): d=30.1 (CH Ar), 31.1, 31.6 (2tBu), 34.2, 34.5
3 2
2C ), 42.9, 45.2, 66.3, 66.5, 68.0, 70.0, 70.8 (7CH ), 126.1, 126.6
2CH ), 133.4, 134.6, 148.1, 148.3, 152.7 (5Cq-Ar), 169.1 ppm (C=
H; CH Ar), 3.46 (s, 4H; NCH ), 3.66 (s, 4H; NCH ), 3.73–3.82(m,
2
2
2
2
q
2
2H; OCH ), 4.14–4.30 (m, 8H; OCH ), 4.43 (d, J=12.7 Hz, 4H;
2
2
Ar
CH Ar), 4.49 (s, 4H; CH ), 6.44 (s, 4H; ArH), 7.09 ppm (s, 4H; ArH).
2
2
O).
1
3
C NMR (101 MHz, CDCl ): d=31.2 (tBu), 31.3 (CH Ar), 31.8 (tBu),
3
2
3
7
1
3.7, 34.2 (2C ), 42.6, 45.8, 46.3, 46.6, 69.5, 70.6, 70.7, 71.0, 72.5,
q
2.9 (10CH ), 124.9, 125.7 (2CH ), 131.8, 135.3, 144.9, 145.2,
2
Ar
[
Ba-6]
52.3, 154.6 (6C ), 166.9 ppm (C=O); MS (ESI+): m/z (%)=1103
q-Ar
+
+
+
1
(
12) [M +H], 1120 (18) [M +NH ], 1125 (100) [M +Na].
H NMR (400 MHz, CDCl , 578C): d=0.95 (s, 18H; tBu), 1.29 (s, 18H;
3
4
tBu), 3.00 (br. s, 6H; NCH ), 3.37–3.49 (m, 8H; CH Ar+NCH ), 3.79
2
2
2
(
br. s, 4H; NCH ), 3.91 (br. s, 4H; OCH ), 3.97 (br. s, 8H; OCH ), 4.06
2 2 2
3
1
-Morpholino-2-phenoxyethan-1-one (11)
(br. s, 4H; OCH ), 4.31 (d, J=13.0 Hz, 4H; CH Ar), 4.37 (br. s, 4H;
2 2
OCH ), 6.90 (s, 4H; ArH), 7.23 ppm (s, 4H; ArH); C NMR (101 MHz,
13
2
Phenol 10 (298 mg, 3.17 mmol) was dissolved in anhydrous THF
CDCl , 578C): d=29.9 (CH Ar), 30.8, 31.4 (2tBu), 34.0, 34.2 (2C ),
3
2
q
(
15 mL) and NaH (138 mg, 3.45 mmol, 60% in mineral oil) was
added. Afterwards, 2-chloro-1-morpholinoethan-1-one 9 (250 mg,
.67 mmol) dissolved in chloroform (5 mL) was added dropwise
4
3.6, 45.5, 46.0, 67.8, 69.6, 70.6, 77.8 (7CH ), 126.0, 126.4 (2
2
CH ), 133.2, 134.4, 148.2, 152.6 (4Cq-Ar), 168.6 ppm (C=O).
Ar
1
and the resulting mixture was allowed to stir at 458C overnight.
The solvent was removed; the crude was dissolved in dichlorome-
thane (20 mL) and washed with water (220 mL). The organic
layer was dried over Na SO , the solvent was removed, and the
[
Ba-7]
1
H NMR (400 MHz, CDCl ): d=1.92 (s, 18H; tBu), 1.61 (s, 18H; tBu),
2
4
3
2
crude product was purified by using automated column chroma-
3.32 (d, J=12.5 Hz, 4H; CH Ar), 3.78–3.82 (m, 4H; OCH ), 3.85–
2
2
tography (solvent: petroleum ether/ethyl acetate 4:1 ! 1:1) to
3.89 (m, 4H; OCH ), 4.01–4.06 (m, 4H; OCH ), 4.13 (s, 4H; OCH ),
2 2 2
1
2
give 11 as a colorless solid (160 mg, 47%). H NMR (400 MHz,
4.32 (d, J=12.5 Hz, 4H; CH Ar), 4.34–4.38 (m, 4H; OCH ), 4.48 (s,
2 2
1
3
CDCl ): d=3.58–3.68 (m, 8H; NCH +OCH ), 4.69 (s, 2H; CH ), 6.94
4H; CH ), 6.84 (s, 4H; ArH), 7.20 ppm (s, 4H; ArH). C NMR
3
3
2
2
2
2
3
(
d, J=8.1 Hz, 2H; ArH), 6.99 (t, J=6.4 Hz, 2H; ArH), 7.27–
(101 MHz, CDCl ): d=29.8 (CH Ar), 31.1, 31.6 (2tBu), 34.1, 34.4
3
2
1
3
1
7
4
1
.31 ppm (m, 2H; ArH); C NMR (101 MHz, CDCl ): d=42.6 (OCH ),
6.1, 66.9, 67.8 (3CH ), 114.7 (CH ), 121.9 (CH ), 129.8 (CH ),
57.8 (Cq-Ar), 166.7 ppm (C=O).
(2C ), 59.7, 66.5, 69.0, 70.9, 71.4, 78.7 (6CH ), 120.1 (q, J =
q 2 C,F
3
2
322 Hz; CF ), 126.0, 126.3 (2CH ), 133.1, 134.8, 147.7, 148.2,
3 Ar
2
Ar
Ar
Ar
19
148.3, 152.3 (6Cq-Ar), 176.1 ppm (C=O); F NMR (565 MHz, CDCl3):
d=À78.9 ppm.
Synthesis of the Barium Complexes
[
Ba-8]
The respective ligand 5–8 (1 equiv) and Ba(ClO4)2 (5 equiv) were
dissolved in acetonitrile. The mixture was treated with ultrasound
for 1 min, the solvent was removed, and chloroform was added.
Afterwards, the solution was filtered and the filtrate contained the
barium complexes in quantitative yield.
1
H NMR (400 MHz, CDCl , 578C): d=0.91 (s, 18H; tBu), 1.28 (s, 18H;
3
tBu), 3.00 (br. s, 6H; NCH ), 3.30–3.47 (m, 4H; CH Ar), 3.77–4.39 (m,
28H; CH ), 6.85 (s, 4H; ArH), 7.20 ppm (s, 4H; ArH); C NMR
(101 MHz, CDCl , 578C): d=29.9 (CH Ar), 31.1, 31.7 (2tBu), 34.1,
2
2
1
3
2
3
2
3
4.4 (2C ), 53.6, 67.1, 69.2, 70.8, 70.9 (5CH ), 126.1, 126.5 (2
q
2
CH ), 133.1, 133.2, 134.7, 148.1, 148.2, 152.6 (6Cq-Ar), 173.4 ppm
Ar
[Ba-1]
(C=O).
1
H NMR (400 MHz, CDCl ): d=0.80 (s, 18H; tBu), 1.33 (s, 18H; tBu),
3
2
3
4
6
.41 (d, J=13.5 Hz, 4H; CH Ar), 3.83–3.95 (m, 8H; OCH ), 4.04 (s,
2
2
UV/Vis Titration Measurements
H; OCH ), 4.13–4.25 (m, 12H; OCH +CH Ar), 6.48 (s, 2H; OH),
2
2
2
1
3
.61 (s, 4H; ArH), 7.11 ppm (s, 4H; ArH); C NMR (101 MHz, CDCl3):
A solution of the corresponding ligand was prepared in acetoni-
trile. The concentration range was chosen to be 1.0 to 2.5 mm, de-
pending on the absorption maxima of the compound. This solu-
tion (2.5 mL) was pipetted into a quartz cuvette of 1 cm optical
path length. The titration was performed by a stepwise addition of
a 25 mm Ba(ClO ) solution in acetonitrile. The absorption spectra
d=31.0 (tBu), 31.6 (CH Ar), 31.8 (tBu), 34.0, 34.1 (2C ), 69.8, 70.2,
2
q
7
1
0.4, 71.1, 75.4 (5CH ), 125.8, 126.0 (2CH), 128.5, 131.6, 143.6,
48.1, 149.2, 149.5 ppm (6Cq-Ar).
2
4
2
[Ba-3]
were measured in the range of 190 to 400 nm.
1
H NMR (400 MHz, CDCl ): d=0.89 (s, 18H; tBu), 1.28 (s, 18H; tBu),
3
3
.36 (br. s, 4H; CH Ar), 3.80–4.45 (m, 20H; OCH ), 4.59 (br. s, 4H;
133
2
2
Extraction Studies of Ligands 5–8 by using [ Ba]BaCl2
CH Ar), 5.28 (s, 4H; CH ), 6.80 (s, 4H; CH Ar), 7.26 ppm (s, 4H; ArH).
2
2
2
13
C NMR (101 MHz, CDCl ): d=30.0 (CH Ar), 31.0 (tBu), 31.6 (tBu),
The respective ligands 5–8 (1 equiv) were dissolved in 600 mL
chloroform. Carrier added [ Ba]BaCl2 (1 equiv, ca. 800 Bq) dis-
3
2
133
3
4.1, 34.4 (2C ), 53.6, 67.0, 69.2, 70.6, 70.7, 73.8 (6CH ), 126.2,
q
2
ChemistryOpen 2018, 7, 432 – 438
437
ꢁ 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim