1156
A. I. Khodair
Vol. 39
(s, 1H, =CH), 13.68 (s, 1H, NH); 13C nmr (DMSO-d6): d 114.08,
117.86, 120.02, 122.66, 148.46, 149.63 (=CH, C-5, C-Ar),
169.20 (C-4), 196.68 (C-2).
Anal. Calcd. for C11H9NO2S2 (251.33): C, 52.57; H, 3.61; N,
5.57. Found: C, 52.29; H, 3.80; N, 5.36.
5-((Z)-2-Hydroxy-3-methoxybenzylidene)-2-methylmercapto-4-
thiazolidinone (4d).
2-Methylmercapto-4-thiazolidinone (3).
This compound has mp 199-201 °C; yield 2.31 g (82%); ir: CO
2-Thioxo-4-thiazolidinone(1) (1.33 g, 10 mmol) were dissolved
in aqueous NaOH (2%, 25 mL) at room temperature. To this solu-
tion methyl iodide (1.56 g, 11 mmol) was added, and the reaction
mixture was stirred overnight at room temperature. The reaction
mixture was diluted with CH2Cl2, washed with cold saturated
aqueous NaHCO3 and water, and dried over anhydrous Na2SO4.
The CH2Cl2 was evaporated till dryness and the residue was crys-
tallized from methanol to yield 1.26 g (86%), mp 72-74 °C (lit [24]
1
1710 cm-1; H nmr (DMSO-d6): d 2.82 (s, 3H, Me), 3.86 (s, 3H,
OMe), 6.92-7.12 (m, 3H, Ar-H), 8.13 (s, 1H, =CH), 9.84 (s, 1H,
OH); 13C nmr(CDCl3): d 15.30 (Me), 55.95 (OMe), 119.62 (=CH),
124.93 (C-5), 114.26, 119.86, 120.36, 130.11, 147.17, 148.00
(C-Ar), 179.11 (C-4), 192.88 (C-2); EI ms: m/z = 281 (M+).
Anal. Calcd. for C12H11NO3S2 (281.35): C, 52.23; H, 3.94; N,
4.98. Found: C, 52.05; H, 4.20; N, 4.74.
1
mp 170 °C); ir: CO 1717 cm-1; H nmr (CDCl3): d 2.75 (s, 3H,
2-Allylmercapto-5-((Z)-2-thienylidene)-4-thiazolidinone (4e).
Me), 4.05 (s, 2H, 5-H); 13C NMR (CDCl3): d 15.89 (Me), 39.44
(C-5), 187.10 (C-4), 202.46 (C-2); EI ms: m/z = 147 (M+).
Anal. Calcd. for C4H5NOS2 (147.22): C, 32.63; H, 3.42; N,
9.51. Found: C, 32.45; H, 3.52; N, 9.70.
This compound has mp 100-102 °C; yield 2.14 g (80%); ir: CO
1
1712 cm-1; H nmr (DMSO-d6): d 4.09 (d, J = 6.9 Hz, 2H, 3-H
allyl), 5.26, 5.40 (2d, J = 10.0, 16.9 Hz, 2H, 1-H allyl), 5.92-6.05 (m,
1H, 2-H allyl), 7.17 (t, J = 4.3 Hz, 1H, 4'-H), 7.68 (d, J = 3.0 Hz, 1H,
3'-H), 7.90 (d, J = 4.6 Hz, 1H, 5'-H), 8.01 (s, 1H, =CH); 13C nmr
(DMSO-d6): d 36.23 (C-3 allyl), 120.37, 124.81, 125.87, 128.17,
128.88, 130.92, 132.34, 133.86, 138.83 (C-2 allyl, =CH, C-1 allyl,
C-5, C-Ar), 179.64 (C-4), 190.33 (C-2); EI ms: m/z = 267 (M+).
Anal. Calcd. for C11H9NOS3 (267.39): C, 49.41; H, 3.39; N,
5.24. Found: C, 49.12; H, 3.57; N, 5.50.
5-((Z)-Arylidene)-2-alkylmercapto-4-thiazolidinones (4a-f).
Method A.
5-((Z)-Arylidene)-2-thioxo-4-thiazolidinones(2a-f) (10 mmol)
were dissolved in aqueous NaOH (2%, 25 mL) at room tempera-
ture. To this solution allyl or methyl iodides (11 mmol) was added,
and the reaction mixture was stirred overnight at room tempera-
ture. The yellow solid that separated was collected by filtration
and recrystallized from methanol to give the products 4a-f.
5-((Z)-2-Furylidene)-2-allylmercapto-4-thiazolidinone (4f).
This compound has mp 72-74 °C; yield 2.27 g (90%); ir: CO
1
1714 cm-1; H nmr (DMSO-d6): d 4.08 (d, J = 7.0 Hz, 2H, 3-H
5-((Z)-Benzylidene)-2-allylmercapto-4-thiazolidinone (4a).
allyl), 5.27, 5.42 (2d, J = 9.7, 18.1 Hz, 2H, 1-H allyl), 5.94-6.03
(m, 1H, 2-H allyl), 6.58 (q, J = 1.8 Hz, 1H, 4'-H), 6.83 (d, J = 3.5
Hz, 1H, 3'-H), 7.60 (s, 1H, =CH), 7.67 (d, J = 1.7 Hz, 1H, 5'-H);
13C nmr (DMSO-d6): d 113.50, 118.60, 120.25, 121.20, 124.24,
131.01, 146.71, 149.81 (C-2 allyl, =CH, C-1 allyl, C-5, C-Ar),
179.78 (C-4), 192.28 (C-2); EI ms: m/z = 251 (M+).
This compound has mp 83-85 °C; yield 2.14 g (82%); ir: CO
1707 cm ; H nmr(deuteriochloroform):d 4.06 (d,J = 7.1 Hz, 2H,
-1 1
3-H allyl), 5.23-5.43 (m, 2H, 1-H allyl), 5.91-6.02 (m, 1H, 2-H
allyl), 7.41-7.49 (m, 5H, Ar-H), 7.84 (s, 1H, =CH); 13C nmr (deu-
teriochloroform): d 36.15 (C-3 allyl), 120.38, 126.15, 129.20,
130.43, 130.70, 130.85, 133.43, 135.92 (C-2 allyl, =CH, C-1 allyl,
C-5, C-Ar ), 179.85 (C-4), 191.79 (C-2); EI ms: m/z = 261 (M+).
Anal. Calcd. for C13H11NOS2 (261.36): C, 59.74; H, 4.24; N,
5.36. Found: C, 59.48; H, 4.40; N, 5.32.
Anal. Calcd. for C11H9NO2S2 (251.33): C, 52.57; H, 3.61; N,
5.57. Found: C, 52.34; H, 3.50; N, 5.72.
Method B.
A mixture of 3 (147 mg, 1 mmol), 4-hydroxybenzaldehyde
(122 mg, 1 mmol) and morpholine (87 mL, 1.1 mmol) in an
hydrous ethanol (3 mL) was stirred for 12 h until the starting
material was consumed (tlc). The reation mixture was diluted
with water and then neutralized with 1M HCl. The yellow solid
separated was collected by filtration and recrystallized from
ethanol to give the product 4c in 88% yield.
5-((Z)-4-Methoxylbenzylidene)-2-allylmercapto-4-thiazoli-
dinone (4b).
This compoundhas mp 154-156 °C; yield 2.44 g (84%); ir: CO
1
1709 cm-1; H nmr (deuteriochloroform): d 3.86 (s, 3H, OMe),
4.05 (d, J = 7.1 Hz, 2H, 3-H allyl), 5.22-5.44 (m, 2H, 1-H allyl),
5.92-6.03 (m, 1H, 2-H allyl), 6.99, 7.46 (2d, J = 8.68 Hz, 4H, Ar-
H), 7.83 (s, 1H, =CH); 13C nmr (deuteriochloroform):d 36.02 (C-
3 allyl), 55.45 (OMe), 114.75, 120.22, 123.33, 125.81, 126.09,
130.95, 132.50, 136.04, 161.65 (C-2 allyl, =CH, C-1 allyl, C-5, C-
Ar ), 180.17 (C-4), 190.94 (C-2); EI ms: m/z = 291 (M+).
Anal. Calcd. for C14H13NO2S2 (291.39): C, 57.71; H, 4.50; N,
4.81. Found: C, 57.63; H, 4.68; N, 5.04.
2-(4-Oxo-thiazolidin-2-ylideneamino)benzoic Acids (6a,b).
A mixture of 2-methylmercapt-4-thiazolidinone (3) (1.47 g, 10
mmol) and the appropriate 2-aminobenzoic acids (10 mmol) in
anhydrous ethanol (30 mL) was heated under reflux for 24 h until
the starting material was consumed (tlc). The yellow solid sepa-
rated was collected by filtration and recrystallized from
dimethylformamide to give the products 6a,b.
5-((Z)-4-Hydroxybenzylidene)-2-methylmercapto-4-thiazolidi-
none (4c).
2-(4-Oxo-thiazolidin-2-ylideneamino)benzoic Acid (6a).
This compoundhas mp 170-172 °C; yield 1.96 g (78%); ir: CO
1707 cm-1; 1H nmr (deuteriochloroform): d 2.81 (s, 3H, Me),
6.95, 7.52 (2d, J = 8.1 Hz, 4H, Ar-H), 7.74 (s, 1H, =CH), 10.48
(s, 1H, OH); 13C nmr (deuteriochloroform): d 15.58 (Me), 122.11
(=CH), 124.32 (C-5), 116.70, 133.20, 135.98, 160.75 (C-Ar ),
179.55 (C-4), 192.21 (C-2); EI ms: m/z = 251 (M+).
This compound has mp 190-192 °C; yield 1.50 g (63%) (lit [17]
mp 187-189 °C, yield 54%); ir: NH 3280, CO 1778, CO 1719 cm-1;
1H nmr (DMSO-d6): d 4.01 (s, 2H, 5-H), 7.05 (br. s, 1H, COOH),
7.23 (t, J = 7.5 Hz, 2H, Ar-H), 7.56 (t, J = 7.3 Hz, 1H, Ar-H), 7.87 (d,
J = 7.6 Hz, 1H, Ar-H), 12.42 (br. s, 1H, NH); EI ms: m/z= 236 (M+).