Chemistry of Heterocyclic Compounds 2017, 53(3), 341–349
J = 8.5, J = 6.6, 3'-CH2); 2.82 (2H, dd, J = 9.5, J = 6.0, 2-
was obtained from 2-[4-(3-phenylpropoxy)phenyl]ethan-1-
CH2); 2.96 (2H, s, 1-CH2); 3.71 (3H, s, CH3); 3.91 (2H, t, J
amine hydrochloride (11c) (0.291 g, 1 mmol). Yield 0.189 g
1
= 6.3, 1'-CH2); 6.78–6.93 (4H, m, H Ar); 7.06–7.23 (4H, m, H
(74%), mp 172–174°C (decomp.). H NMR spectrum, δ,
+
Ar); 8.04 (3H, br. s, NH3 ). 13C NMR spectrum, δ, ppm:
ppm (J, Hz): 1.99 (2H, dq, J = 9.0, J = 6.4, 2'-CH2); 2.60–
2.78 (4H, m, 2,3'-CH2); 2.82 (2H, t, J = 7.4, 1-CH2); 3.92
(2H, t, J = 6.4, 1'-CH2); 6.85 (2H, d, J = 8.6, H Ar); 7.11 (2H,
d, J = 8.6, H Ar); 7.15–7.35 (5H, m, H Ar); 8.10 (2H, br. s,
NH2). 13C NMR spectrum, δ, ppm: 30.4; 31.5; 35.6; 42.0;
66.6; 114.4; 125.8; 128.3; 129.6; 130.7; 141.4; 157.1. Found,
m/z: 256.1701 [M+H]+. C17H22NO. Calculated, m/z: 256.1701.
2-{4-[2-(4-Methoxyphenyl)ethoxy]phenyl}ethan-1-
30.6; 32.2; 40.2; 55.0; 66.6; 113.8; 114.6; 129.1; 129.3;
129.7; 133.2; 157.5. Found, m/z: 286.1805 [M+H]+.
C18H24NO2. Calculated, m/z: 286.1807.
2-[4-(3-Phenylpropoxy)phenyl]ethan-1-amine
hydro-
chloride (11c) was obtained from tert-butyl {2-[4-(3-
phenylpropoxy)phenyl]ethyl}carbamate (10c) (4.301 g,
12.1 mmol). Yield 3.523 g (98%), mp 212–260°C
1
(decomp.). H NMR spectrum, δ, ppm (J, Hz): 1.87–2.12
amine (12d) was obtained from 2-{4-[2-(4-methoxyphenyl)
ethoxy]phenyl}ethan-1-amine hydrochloride (11d) (0.308 g, 1
(2H, m, 2'-CH2); 2.73 (2H, dd, J = 8.7, J = 6.6, 3'-CH2);
2.82 (2H, dd, J = 9.6, J = 6.0, 2-CH2); 2.97 (2H, dd, J =
9.1, J = 5.9, 1-CH2); 3.93 (2H, t, J = 6.4, 1'-CH2); 6.88 (2H,
d, J = 8.4, H Ar); 7.06–7.38 (7H, m, H Ar); 8.06 (3H, br. s,
1
mmol). Yield 0.125 g (46%), mp 216–218°C. H NMR
spectrum, δ, ppm (J, Hz): 2.78 (2H, dd, J = 9.5, J = 6.1, 2-
CH2); 2.87–3.01 (4H, m, 1,2'-CH2); 3.72 (3H, s, CH3); 4.10
(2H, t, J = 6.9, 1'-CH2); 6.82–6.94 (4H, m, H Ar); 7.15 (2H,
d, J = 8.6, H Ar); 7.23 (2H, d, J = 8.6, H Ar); 8.06 (2H, br.
s, NH2). 13C NMR spectrum, δ, ppm: 32.7; 34.1; 40.5; 55.0;
68.4; 113.8; 114.6; 129.5; 129.7; 129.9; 130.2; 157.2; 157.8.
Found, m/z: 272.1649 [M+H]+. C17H22NO2. Calculated, m/z:
272.1650.
+
NH3 ). 13C NMR spectrum, δ, ppm 30.4; 31.5; 32.1; 40.1;
66.6; 114.6; 125.8; 128.3; 129.2; 129.7; 141.4; 157.4.
Found, m/z: 256.1705 [M+H]+. C17H22NO. Calculated, m/z:
256.1701.
2-{4-[2-(4-Methoxyphenyl)ethoxy]phenyl}ethan-1-amine
hydrochloride (11d) was obtained from tert-butyl (2-{4-[2
-(4-methoxyphenyl)ethoxy]phenyl}ethyl)carbamate (10d)
(4.495 g, 12.1 mmol). Yield 3.427 g (92%), mp 210–211°C.
1H NMR spectrum, δ, ppm (J, Hz): 2.82 (2H, dd, J = 9.6,
J = 6.0, 2-CH2); 2.95 (4H, t, J = 6.8, 1,2'-CH2); 3.72 (3H, s,
CH3); 4.11 (2H, t, J = 6.9, 1'-CH2); 6.81–6.94 (4H, m,
H Ar); 7.16 (2H, d, J = 8.6, H Ar); 7.23 (2H, d, J = 8.7,
Preparation of 3-(2-[4-(arylalkoxy)phenyl]ethyl)-2-
thioxo-1,3-thiazolidin-4-ones 5b–d under MW irradia-
tion (General method). A mixture of bis(carboxymethyl)-
trithiocarbonate (13) (131 mg, 0.58 mmol), DME (2 ml),
Et3N (81 ml, 1 equiv), and 2-(4-phenylalkyloxy)phenyl-
ethan-1-amine 12b–d (1 equiv) in a sealed glass tube was
placed in the MW cavity (800 W) and irradiated at 90°C
for 15–20 min under vigorous stirring. After heating, the
crude reaction mixture was allowed to cool down to room
temperature and concentrated under reduced pressure. The
crude reaction mixture was dissolved in MeOH (1 ml),
cooled H2O (2 ml) was added, and stirring was pursued
until complete precipitation of the desired compound 5b–d.
The resulting precipitate was filtered, purified by recrystal-
lization from absolute EtOH, and dried in vacuum
(10−2 Torr) at 25°C for 1 h.
3-(2-{4-[3-(4-Methoxyphenyl)propoxy]phenyl}ethyl)-
2-thioxo-1,3-thiazolidin-4-one (5b) was obtained from 2-{4-
[3-(4-methoxyphenyl)propoxy]phenyl}ethan-1-amine
(12b) (0.166 g, 0.58 mmol). Yield 0.173 g (65%), mp 105–
106°C. 1H NMR spectrum, δ, ppm (J, Hz): 1.96 (2H, dq, J
= 13.3, J = 6.5, 2"-CH2); 2.66 (2H, t, J = 7.6, 3"-CH2); 2.71
–2.83 (2H, m, 2'-CH2); 3.71 (3H, s, CH3); 3.90 (2H, t, J =
6.3, 1'-CH2); 3.94–4.06 (2H, m, 1"-CH2); 4.24 (2H, s, 5-
CH2); 6.85 (4H, d, J = 8.4, H Ar); 7.12 (4H, d, J = 8.4, H
Ar). 13C NMR spectrum, δ, ppm: 30.6; 30.7; 31.2; 35.9;
45.3; 55.0; 66.6; 113.8; 114.6; 129.3; 129.5; 129.7; 133.2;
157.4; 157.5; 174.2 (C=O); 203.0 (C=S). Found, m/z:
424.1019 [M+Na]+. C21H23NNaO3S2. Calculated, m/z:
424.1017.
+
H Ar); 8.06 (3H, br. s, NH3 ). 13C NMR spectrum, δ, ppm:
32.1; 34.1; 40.1; 55.0; 68.4; 113.7; 114.6; 129.2; 129.7;
129.9; 130.2; 157.3; 157.8. Found, m/z: 272.1649 [M+H]+.
C17H22NO2. Calculated, m/z: 272.1650.
Preparation of 2-[4-(arylalkoxy)phenyl]ethan-1-
amines 12b–d (General method). NaOMe (0.081 g, 1.5 equiv)
was added to a suspension of 2-(4-phenylalkyloxy)phenyl-
ethan-1-amine hydrochloride 11 (1 mmol) in absolute
MeOH (3 ml), and the reaction mixture was refluxed under
vigorous stirring (550 rpm) for 6 h. After cooling to room
temperature, the reaction mixture was concentrated under
reduced pressure. To the crude residue, H2O (5 ml) was
added, and mixing was pursued until complete precipitation
of the desired amine 12. The resulting precipitate was
filtered and washed with H2O (5 × 1 ml), then dried in
vacuum (10−2 Torr) at 25°C for 1 h and stored at 4°C.
Compounds 12 were used in next step without further puri-
fication.
2-{4-[3-(4-Methoxyphenyl)propoxy]phenyl}ethan-1-
amine (12b) was obtained from 2-{4-[3-(4-methoxy-
phenyl)propoxy]phenyl}ethan-1-amine
hydrochloride
(11b) (0.321 g, 1 mmol). Yield 0.263 g (92%), mp 195–
1
197°C. H NMR spectrum, δ, ppm (J, Hz): 1.85–2.07 (2H,
m, 2'-CH2); 2.59–2.76 (4H, m, 2,3'-CH2); 2.86 (2H, dd,
J = 8.9, J = 6.2, 2-CH2); 3.71 (3H, s, CH3); 3.90 (2H, t,
J = 6.3, 1'-CH2); 6.79–6.93 (4H, m, H Ar); 7.07–7.21 (4H,
m, H Ar); 8.01 (2H, br. s, NH2). 13C NMR spectrum,
δ, ppm: 30.6; 30.7; 35.1; 41.7; 55.0; 66.6; 113.8; 114.5;
129.3; 129.7; 130.5; 133.2; 157.2; 157.5. Found, m/z:
286.1811 [M+H]+. C18H24NO2. Calculated, m/z: 286.1807.
2-[4-(3-Phenylpropoxy)phenyl]ethan-1-amine (12c)
3-{2-[4-(3-Phenylpropoxy)phenyl]ethyl}-2-thioxo-1,3-
thiazolidin-4-one (5c) was obtained from 2-[4-(3-phenyl-
propoxy)phenyl]ethan-1-amine (12c) (0.148 g, 0.58 mmol).
1
Yield 0.052 g (24%), mp 82–86°C. H NMR spectrum,
δ, ppm (J, Hz): 1.91–2.08 (2H, m, 2"-CH2); 2.75 (4H, m,
2',3"-CH2); 3.93 (2H, t, J = 6.4, 1'-CH2); 3.96–4.05 (2H, m,
1"-CH2); 4.23 (2H, s, 5-CH2); 6.86 (2H, d, J = 8.6, H Ar);
348