Molecules 2021, 26, 1466
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0.49 (1:4 EtOAc/hexanes); HPLC tR 25.8 min; UV vis (CH3CN-H2O)
λ
max
235, 298nm; 1H
NMR (300 MHz, CDCl3):
δ 7.34 (d, J = 8.1 Hz, 1H, Ar), 7.23 (t, J = 7.8 Hz, 1H, Ar), 7.15 (d,
J = 7.0 Hz, 1H, Ar), 5.09 (s, 2H, C(3)CH2O), 4.41 (q, J = 7.1 Hz, 2H, N(1)OCH2), 3.99 (s, 3H,
CO2CH3), 3.65 (q, J = 7.0 Hz, 2H, OCH2CH3), 1.44 (t, J = 7.1 Hz, 3H, N(1)OCH2CH3), 1.25
(t, J = 7.0 Hz, 3H, OCH2CH3); 13C NMR (75 MHz, CDCl3):
δ 160.8 (C=O), 136.2 (Ar), 128.6
(Ar), 126.1 (Ar), 125.3 (Ar), 122.8 (Ar), 119.5 (Ar), 116.4 (Ar), 108.4 (Ar), 74.9 (N(1)OCH2),
65.8 (OCH2CH3), 61.9 (C(3)CH2O), 52.3 (CO2CH3), 15.5 (N(1)OCH2CH3), 13.7 (OCH2CH3);
MS m/z 311 [M]+; HRMS (+ESI) calcd for C15H18ClNNaO4 [M + Na]+ 334.0822, found
334.0820.
Methyl 4-Chloro-1-n-propyloxy-3-[(n-propyloxy)methyl]-1H-indole-2-carboxylate (1xc)
Use of SnCl2
·
2H2O (140 mg, 0.62 mmol, 3.3 eq), n-propanol (28
µ
L, 0.37 mmol, 2.0 eq)
◦C
and 2x (50 mg, 0.185 mmol, 1.0 eq) for 1 h at 40 , then use of DBU (272
µL, 1.85 mmol,
◦
10.0 eq) and 1-bromopropane (34
µ
L, 0.37 mmol, 2.0 eq) for 1 h at 25 C in general procedure
afforded the title compound 1xc (18.9 mg, 30%) as a white oil. Bp 170 ◦C (decomp.); Rf
0.54 (1:4 EtOAc/hexanes); HPLC tR 30.8 min; UV vis (CH3CN-H2O)
λ
230, 298nm; 1H
max
NMR (300 MHz, CDCl3):
δ 7.35 (d, J = 7.9 Hz, 1H, Ar), 7.23 (t, J = 8.0 Hz, 1H, Ar), 7.15
(d, J = 7.1 Hz, 1H, Ar), 5.09 (s, 2H, C(3)CH2O), 4.29 (t, J = 6.4 Hz, 2H, N(1)OCH2), 3.98 (s,
3H, CO2CH3), 3.54 (t, J = 6.5 Hz, 2H, OCH2), 1.86 (sextet, J = 6.9 Hz, 2H, N(1)OCH2CH2),
1.64 (sextet, J = 7.0 Hz, 2H, OCH2CH2), 1.11 (t, J = 7.2 Hz, 3H, N(1)OCH2CH2CH3), 0.93 (t,
J = 7.3 Hz, 3H, OCH2CH2CH3); 13C NMR (75 MHz, CDCl3):
δ 160.9 (C=O), 136.1 (Ar), 128.6
(Ar), 126.0 (Ar), 125.3(Ar), 122.8 (Ar), 119.6 (Ar), 116.4 (Ar), 108.3 (Ar), 80.6 (N(1)OCH2),
72.4 (OCH2), 62.1 (C(3)CH2O), 52.2 (CO2CH3), 23.1 (N(1)OCH2CH2), 21.8 (OCH2CH2),
10.9 (N(1)O(CH2)2CH3), 10.6 (O(CH2)2CH3); MS m/z 339 [M]+; HRMS (+ESI) calcd for
C17H22ClNO4 [M + Na]+ 362.1135, found 362.1134.
Methyl 4-Chloro-1-n-butyloxy-3-[(n-butyloxy)methyl]-1H-indole-2-carboxylate (1xd)
Use of SnCl2 2H2O (82.8 mg, 0.37 mmol, 3.3 eq), n-butanol (21 µL, 0.22 mmol, 2.0 eq)
·
and 2x (30 mg, 0.11 mmol, 1.0 eq) for 1 h at 40 ◦C, then use of DBU (165
µL, 1.10 mmol,
◦
10.0 eq) and 1-bromobutane (24
µL, 0.22 mmol, 2.0 eq) for 1 h at 25 C in general procedure
afforded the title compound 1xd (12.9 mg, 32%) as a white oil. Bp 198 ◦C (decomp.); Rf
0.54 (1:4 EtOAc/hexanes); HPLC tR 34.3 min; UV vis (CH3CN-H2O)
λ
max
235, 298 nm; 1H
NMR (300 MHz, CDCl3):
δ 7.34 (d, J = 8.2 Hz, 1H, Ar), 7.23 (t, J = 8.2 Hz, 1H, Ar), 7.15 (d,
J = 7.4 Hz, 1H, Ar), 5.08 (s, 2H, C(3)CH2O), 4.32 (t, J = 6.5 Hz, 2H, N(1)OCH2), 3.98 (s, 3H,
CO2CH3), 3.58 (t, J = 6.5 Hz, 2H, OCH2), 1.82 (quintet, J = 7.0 Hz, 2H, N(1)OCH2CH2), 1.65–
1.52 (m, 4H, OCH2CH2, N(1)OCH2CH2CH2), 1.39 (sextet, J = 7.5 Hz, 2H, O(CH2)2CH2),
1.00 (t, J = 7.4 Hz, 3H, N(1)O(CH2)3CH3), 0.90 (t, J = 7.4 Hz, 3H, O(CH2)3CH3); 13C
NMR (75 MHz, CDCl3):
δ 160.9 (C=O), 136.1 (Ar), 128.6 (Ar), 126.0 (Ar), 125.3 (Ar), 122.8
(Ar), 119.6 (Ar), 116.4 (Ar), 108.3 (Ar), 79.0 (N(1)OCH2), 70.4 (OCH2), 62.1 (C(3)CH2O),
52.3 (CO2CH3), 32.1 (N(1)OCH2CH2), 30.5 (OCH2CH2) 19.6 (N(1)O(CH2)2CH2), 19.4
(O(CH2)2CH2) 14.2 (N(1)O(CH2)3CH3), 14.1 (O(CH2)3CH3); MS m/z 367 [M]+; HRMS
(+ESI) calcd for C19H26ClNO4 [M + Na]+ 390.1448, found 390.1447.
Methyl 4-Chloro-1-n-pentyloxy-3-[(n-pentyloxy)methyl]-1H-indole-2-carboxylate (1xe)
Use of SnCl2 2H2O (82.8 mg, 0.37 mmol, 3.3 eq), n-pentanol (24 µL, 0.22 mmol, 2.0 eq)
·
and 2x (30 mg, 0.11 mmol, 1.0 eq) for 2 h at 40 ◦C, then use of DBU (165
µL, 1.10 mmol,
◦
10.0 eq) and 1-bromopentane (28
afforded the title compound 1xe (8.7 mg, 20%) as a white oil. Bp 184 C (decomp.); Rf
0.58 (1:4 EtOAc/hexanes); HPLC tR 32.9 min; UV vis (CH3CN-H2O)
µ
L, 0.22 mmol, 2.0 eq) for 1 h at 25 C in general procedure
◦
λ
max
235, 298 nm; 1H
NMR (300 MHz, CDCl3):
δ 7.34 (d, J = 8.1 Hz, 1H, Ar), 7.23 (t, J = 8.1 Hz, 1H, Ar), 7.15
(d, J = 7.5 Hz, 1H, Ar), 5.08 (s, 2H, C(3)CH2O), 4.32 (t, J = 6.6 Hz, 2H, N(1)OCH2), 3.98 (s,
3H, CO2CH3), 3.59 (t, J = 6.7 Hz, 2H, OCH2), 1.84 (quintet, J = 7.4 Hz, 2H, N(1)OCH2CH2),
1.64–1.25 (m, 10H, OCH2(CH2)3CH3, N(1)OCH2CH2(CH2)2CH3), 0.95 (t, J = 7.2 Hz, 3H,
N(1)O(CH2)4CH3), 0.87 (t, J = 6.9 Hz, 3H, O(CH2)4CH3); 13C NMR (75 MHz, CDCl3):
δ
160.8 (C=O), 136.0 (Ar), 128.6 (Ar), 126.0 (Ar), 125.3 (Ar), 122.8 (Ar), 119.6 (Ar), 116.4