JOURNAL OF BIOMOLECULAR STRUCTURE AND DYNAMICS
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in dry deuterated DMSO on a Bruker AC spectrometer at
4.2.1.5.
(Z)-5-(2,4-dichlorobenzylidene)thiazolidine-2,4-
1
200 MHz for H NMR and 50 MHz for 13C NMR. Mass spectra
dione (3e). White solid, Yield: 89%, mp ¼ 216 ꢀC (EtOH), Lit
(Zhang & Zhou, 2012). 213–215 ꢀC. FTIR (ATR, cmꢁ1): 3310
(NH), 3040 (ArC-H), 1700 (C ¼ O), 1602 (C ¼ O). 1H-NMR
(200 MHz, DMSO-d6, d (ppm)): 7.99 (1H, s, ArCH¼C); 7.23 (1H,
d, J ¼ 2.0 Hz, H Ar); 7.18 (1H, d, J ¼ 8.5 Hz, H Ar); 7.12 (1H, dd,
J ¼ 8.5, 2.0 Hz, H Ar). 13C-NMR (50 MHz, DMSO-d6, d (ppm)):
166.5, 164.0, 139.4, 135.3, 129.6, 128.9, 128.4, 128.0, 126.5,
118.0. MS (ESIþ): m/z ¼ 275.1 [M þ H]þ.
(ESI-MS) were recorded on a Bruker Daltonics Esquire 3000þ,
and the samples were diluted in methanol.
4.2. Chemistry
4.2.1. General procedure for the synthesis of (Z)-5-arylide-
nethiazolidine-2,4-dione 3a-3e
A mixture of TZD (1 mmol) and aromatic aldehyde (1 mmol)
was dissolved in CH2Cl2 (5 mL) then mineral support (1 g)
was added and stirred. After 5 min the solvent was removed
under vacuum and the dry-powder was irradiated in a micro-
wave for appropriate time. After the completion of reaction,
CH2Cl2 is added the chilled reaction mixture, then stirred for
5 min. The reaction mixture is filtered under vacuum and
washed with of CH2Cl2 (3 ꢂ 5 mL). The combined organics
were dried over MgSO4 and the solvent was evaporated
under reduced pressure, the product was crystallized in etha-
nol to give pure product.
4.2.2. General procedure for the synthesis of 3-allyl-5-ary-
lidenethiazolidine-2,4-dione 4a-4e
The thiazolidine-2,4-dione derivatives (4a–4e) were synthe-
sized according to the previously described procedures
(Thari et al., 2020). A mixture of 5-arylidenethiazolidine-2,4-
dione (3a–3e) (1 mmol), allyl bromide (1.2 mmol) in EtOH/
H2O (v/v; 2:1) (10 mL) was treated with sodium hydroxide
(1 mmol), were added. The resulting mixture was stirred and
heated at 75 ꢀC for 5–6 h. The completion of the reaction
was monitored by TLC. The reaction mixture was cooled and
acidified with diluted HCl (4 N). The precipitated solid was fil-
tered and purified by recrystallization from ethanol to give
pure compounds 4a–4e.
4.2.1.1. (Z)-5-benzylidenethiazolidine-2,4-dione (3a). White
solid, Yield: 95% (144 mg), mp ¼ 247 ꢀC (EtOH), Lit (Giles
et al., 2000). 247–249 ꢀC. FTIR (ATR, cmꢁ1): 3220 (NH),
2900–3009 (C-H), 1736 (C ¼ O), 1681 (C ¼ O). 1H-NMR
(200 MHz, DMSO-d6) d, ppm (J, Hz): 12.60 (1H, s, NH); 7.76
(1H, s, PhCH ¼ C); 7.59–7.43 (5H, m, H Ar). 13C-NMR (50 MHz,
DMSO-d6): d, ppm: 167.7 (C ¼ O); 167.2 (C ¼ O); 132.9
(CH ¼ C); 131.6 (C-5 TZD); 130.3 (C-1 Ar); 129.9 (C-3 Ar); 129.2
(C-2 Ar); 123.4 (C-4 Ar). MS (ESIþ): m/z ¼ 206.1 [M þ H]þ.
4.2.2.1. 3-Allyl-5-(benzylidene) thiazolidine-2,4-dione (4a).
White solid, Yield: 62%, mp ¼ 102 ꢀC (EtOH). FTIR (ATR,
cmꢁ1): 3210 (NH), 3048 (ArC-H), 1731 (C ¼ O), 1674 (C ¼ O).
1H-NMR (200 MHz, DMSO-d6, d (ppm)): 8.01–7.88 (m, 2H, H
Ar), 7.63–7.38 (m, 3H, H Ar), 7.51 (s, 1H, ArCH¼C), 6.08–5.67
(m, 1H, CH¼CH2), 5.30 (dd, J ¼ 13.7, 10.2 Hz, 1H, CH¼CH2),
5.05 (dd, J ¼ 16.5, 13.8 Hz, 1H, -CH¼CH2), 4.15 (d, J ¼ 6.2 Hz,
2H, N-CH2).13C-NMR (50 MHz, DMSO-d6,d (ppm)): 172.1, 169.1,
136.1, 133.1, 132.9, 130.2, 129.7, 129.1, 118.1, 117.6, 44.2. MS
(ESIþ): m/z ¼ 246.1 [M þ H]þ.
4.2.1.2. (Z)-5-(4-methylbenzylidene) thiazolidine-2,4-dione
(3 b). White solid, Yield: 92%, mp ¼ 230 ꢀC (EtOH), Lit (Zhang
& Zhou, 2012). 230–232 ꢀC. FTIR (ATR, cmꢁ1): 3188 (NH), 3044
1
(ArC-H), 1733 (C ¼ O), 1681 (C ¼ O). H-NMR (200 MHz, DMSO-
d6, d (ppm)): 12.56 (1H, s, NH); 7.73 (1H, s, ArCH ¼ C); 7.46
(2H, d, J ¼ 4.4 Hz,H Ar); 7.32 (2H, d, J ¼ 4.4 Hz, H Ar); 2.33 (3H,
s, CH3). 13C-NMR (50 MHz, DMSO-d6, d (ppm)): 167.8, 167.3,
140.6, 131.8, 130.2, 130.0, 129.8, 122.2, 21.0. MS (ESIþ):
m/z ¼ 220.2 [M þ H]þ.
4.2.2.2. 3-Allyl-5-(4-methylbenzylidene) thiazolidine-2,4-
dione (4 b). White solid, Yield: 65%, mp ¼ 117 ꢀC (EtOH).
FTIR (ATR, cmꢁ1): 3320 (NH), 3048 (ArC-H), 1728 (C ¼ O), 1668
(C ¼ O). 1H-NMR (200 MHz, DMSO-d6, d (ppm)): 7.81 (1H, s,
ArCH¼C); 7.34 (2H, d, J ¼ 8.2 Hz, H Ar); 7.21 (2H, d, J ¼ 7.2 Hz,
H Ar); 5.88–5.69 (1H, m, CH¼CH2); 5.23 (1H, dd, J ¼ 12 Hz,
1.4 Hz, CH ¼ CH2); 5.16 (1H, dd, J ¼ 5.7 Hz, 1.4 Hz, CH ¼ CH2);
4.27 (2H, d, J ¼ 6.0 Hz, NCH2); 2.33 (3H, s, CH3). 13C-NMR
(50 MHz, DMSO-d6, d (ppm)): 167.6, 166.0, 141.3, 134.0, 130.4,
130.3, 130.2, 129.9, 120.1, 118.8, 43.7, 21.5. MS (ESIþ):
m/z ¼ 260.0 [M þ H]þ, 282.0 [M þ Na]þ.
4.2.1.3. 5-(4-Fluorobenzylidene) thiazolidine-2,4-dione (3c).
Yellow solid, Yield: 97%, mp ¼ 219 ꢀC (EtOH), Lit (Giles et al.,
2000). 219–220 ꢀC. FTIR (ATR, cmꢁ1): 3132 (NH), 3042 (ArC-H),
1750 (C ¼ O), 1689 (C ¼ O). 1H-NMR (200 MHz, DMSO-d6, d
(ppm)): 12.60 (1H, s, NH); 7.77 (1H, s, ArCH ¼ C); 7.64 (2H, m,
H Ar); 7.35 (2H, m, H Ar). 13C-NMR (50 MHz, DMSO-d6, d
(ppm)): 167.7, 167.3, 162.7, 132.3, 130.5, 129.7, 123.3, 116.14.
MS (ESIþ): m/z ¼ 224.1 [M þ H]þ.
4.2.2.3. 3-Allyl-5-(4-fluorobenzylidene) thiazolidine-2,4-
dione (4c). White solid, Yield: 58%, mp ¼ 121 ꢀC (EtOH). FTIR
(ATR, cmꢁ1): 3225 (NH), 3042 (ArC-H), 1735 (C ¼ O), 1684
(C ¼ O). 1H-NMR (200 MHz, DMSO-d6, d (ppm)): 7.80 (1H, s,
ArCH¼C); 7.52 ꢁ 7.35 (2H, m, H Ar); 7.24 ꢁ 7.01 (2H, m, H Ar);
5.93 ꢁ 5.64 (m, CH¼CH2); 5.24 (1H, dd, J ¼ 12.0, 2.0 Hz,
CH ¼ CH2); 5.17 (1H, dd, J ¼ 6.0, 2.0 Hz, CH ¼ CH2); 4.28 (2H, d,
J ¼ 6.0 Hz, NCH2). 13C-NMR (50 MHz, DMSO-d6, d (ppm)):
4.2.1.4. 5-(4-Bromobenzylidene) thiazolidine-2,4-dione
(3d). White solid, Yield: 93%, mp ¼ 246 ꢀC (EtOH), Lit (Giles
et al., 2000). 242–244 ꢀC. FTIR (ATR, cmꢁ1): 3200 (NH), 3042
1
(ArC-H), 1713 (C ¼ O), 1608 (C ¼ O). H-NMR (200 MHz, DMSO-
d6, d (ppm)): 12.31 (1H, s, NH); 7.77 (2H, d, J ¼ 7.5 Hz, H Ar);
7.61 (2H, d, J ¼ 6.8 Hz, H Ar); 7.55 (1H, s, ArCH¼C). 13C-NMR
(50 MHz, DMSO-d6, d (ppm)): 173.0, 172.4, 138.1, 136.9, 135.5, 167.1, 166.1, 163.4, 132.6, 132.2, 130.0, 129.5, 121.0, 119.0,
135.1, 134.4, 128.7. MS (ESIþ): m/z ¼ 284.4 [M þ H]þ.
116.3, 43.8. MS (ESIþ): m/z ¼ 264.2 [M þ H]þ.