Molecules 2020, 25, 1915
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Ar–H), 8.69 (s, 8H, OH). 13C {1H} NMR (125 MHz, DMSO-d6):
δ
10.4, 14.5, 28.7, 32.9, 34.5, 60.1, 112.3,
121.6, 124.6, 149.8, 173.3.
3.2.3. Synthesis of Cavitand 3
Cavitand 2 (1.89 g, 2.0 mmol) and K2CO3 (1.38 g, 10 mmol) were dissolved in 50 mL of DMSO in a
100 mL round-bottom flask under argon flowing. The mixture was equipped with a magnetic stirrer
and stirred for one hour at room temperature. Subsequently, ClCH2Br (1.55 g, 12.0 mmol) was added
to the reaction mixture, the flask was stirred at 60 ◦C for 48 h under argon atmosphere. The mixture
was cooled to room temperature and poured into 250 mL of 2% hydrochloric acid. The precipitate
was filtered through a glass filter and washed with ice cold water and dried under vacuum at 80 ◦C.
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Yield: 1.83 g/92%. H NMR (500.1 MHz, CDCl3):
δ 1.29 (t, J = 7.1 Hz, 12H), 1.96 (s, 12H, Ar–CH3),
2.37 (t, J = 6.6 Hz, 8H), 2.58 (tt, J = 6.6 Hz, 8H), 4.17 (q, J = 7.1 Hz, 8H), 4.26 (d, J = 7.6 Hz, 4H,
inner of OCH2O), 4.84 (q, 4H, –CH2–CH), 5.89 (d, J = 7.6 Hz, 4H, outer of OCH2O), 7.02 (s, 4H, Ar–H).
13C {1H} NMR (125 MHz, CDCl3):
δ 10.3, 14.2, 25.3, 32.8, 36.6, 60.4, 98.4, 117.1, 124.1, 137.3, 153.6, 173.1.
3.2.4. Synthesis of Cavitand 4
Cavitand
3 (1.99 g, 2.0 mmol), NBS (2.85 g, 16 mmol) and AIBN (0.263 g, 0.16 mmol) were
dissolved in 50 mL of benzene in a 100 mL round-bottom flask under argon. The reaction mixture was
stirred at 80 ◦C for 24 h under argon atmosphere. The reaction mixture was filtered through celite and
evaporated. The crude residue was dissolved again in CH2Cl2 and washed with water. The organic
layers were dried and evaporated to dryness. The resulting residue was washed with 10 mL methanol,
the precipitate was filtered through a glass filter and washed with small portions of methanol and
1
dried under vacuum at 80 ◦C. Yield: 2.2 g/84%. H NMR (500.1 MHz, CDCl3):
δ 1.29 (t, J = 7.1 Hz,
12H), 2.36 (t, J = 6.6 Hz, 8H), 2.60 (t, J = 6.6 Hz, 8H), 4.18 (q, J = 7.1 Hz, 8H), 4.43 (s, 8H, Ar–CH2–),
4.60 (d, J = 7.6 Hz, 4H, inner of OCH2O), 4.86 (q, 4H, –CH2–CH), 6.05 (d, J = 7.6 Hz, 4H, outer of
OCH2O), 7.22 (s, 4H, Ar–H). 13C {1H} NMR (125 MHz, CDCl3):
125.1, 126.4, 137.4, 153.8, 173.1.
δ 14.2, 25.3, 32.5, 36.5, 60.6, 99.2, 120.1.1,
3.2.5. Synthesis of Cavitand 5
Dimethyl 5-hydroxyisophthalate (2.10 g, 10 mmol) and K2CO3 (2.07 g, 15 mmol) were dissolved
in 50 mL of DMSO in a 100 mL round-bottom flask under argon. The mixture was equipped with
a magnetic stirrer and stirred for one hour at room temperature. Subsequently, Cavitand
4 (1.31 g,
◦
1.0 mmol) was added to the reaction mixture, the flask was stirred at 80 C for 48 h under argon
atmosphere. The mixture was cooled to room temperature and poured into 250 mL of 2% hydrochloric
acid. The precipitate was filtered through a glass filter and washed with ice cold water and small
1
portion of n-hexane, and dried under vacuum at 80 ◦C. Yield: 1.64g/90%. H NMR (500.1 MHz, CDCl3):
δ
1.31 (t, J = 7.1 Hz, 12H), 2.43 (t, J = 6.6 Hz, 8H), 2.69 (t, J = 6.6 Hz, 8H), 3.86 (s, COOMe, 24H),
4.21 (q, J = 7.1 Hz, 8H), 4.62 (d, J = 7.6 Hz, 4H, inner of OCH2O), 4.96 (q, 4H, –CH2–CH), 5.00 (s, 8H,
Ar–CH2–), 5.83 (d, J = 7.6 Hz, 4H, outer of OCH2O), 7.36 (s, 4H, Ar–H). 7.78 (s, 8H, Ar–H), 8.26 (s, 4H,
Ar–H). 13C {1H} NMR (125 MHz, CDCl3):
δ 14.2, 25.3, 32.5, 36.5, 52.3, 61.4, 99.9, 120.0, 120.8, 120.9,
122.7, 125.1, 126.4, 137.4, 139.1, 153.8, 165.9, 173.1.
3.2.6. Synthesis of Cavitand 6
Cavitand
5 (0.91 g, 0.5 mmol) was dissolved in 20 mL of THF in a 100 mL round-bottom flask,
then 3 cm3 Claisen’s alkali (prepared by dissolving 350 g of KOH in 250 cm3 of water, cooling and
diluting to 1 L with MeOH) was added to the reaction mixture). The reaction mixture was refluxed
at 70 ◦C for 24 h. The mixture was cooled to room temperature and the solution was acidified with
2 M hydrochloric acid. The precipitate was filtered through a glass filter and washed with ice cold
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water and small portion of n-hexane, and dried under vacuum at 80 ◦C. Yield: 528 mg/66%. H NMR
(500.1 MHz, DMSO-d6):
δ 2.32 (t, J = 6.6 Hz, 8H), 2.73 (tt, J = 6.6 Hz, 8H), 4.47 (d, J = 7.6 Hz, 4H, inner of