Potassium-tertiary butoxide-assisted addition of thioglicolic acid to chalcone derivatives under solvent-free conditions

Article abstract of DOI:10.1080/00397910903291129

A series of chalcone derivatives containing thioglicolic acid (4a-j) was prepared by addition of thioglicolic acid to the chalcones (3a-j) in the presence of KOt-Bu under solvent-free conditions. The mechanistic pathway of the reaction can be explained by

Full text of DOI:10.1080/00397910903291129

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Potassium–Tertiary Butoxide–Assisted
Addition of Thioglicolic Acid to Chalcone
Derivatives Under Solvent-Free
Conditions
Mustafa Ceylan a , Meliha Burcu Gürdere a , Hayreddin Gezegen a &
Yakup Budak a
a Department of Chemistry, Faculty of Arts and Sciences ,
Gaziosmanpasa University , Tokat, Turkey
Published online: 05 Aug 2010.
To cite this article: Mustafa Ceylan , Meliha Burcu Gürdere , Hayreddin Gezegen & Yakup Budak
(2010) Potassium–Tertiary Butoxide–Assisted Addition of Thioglicolic Acid to Chalcone Derivatives
Under Solvent-Free Conditions, Synthetic Communications: An International Journal for Rapid
Communication of Synthetic Organic Chemistry, 40:17, 2598-2606, DOI: 10.1080/00397910903291129
To link to this article: http://dx.doi.org/10.1080/00397910903291129
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Synthetic Communications1, 40: 2598–2606, 2010
Copyright # Taylor & Francis Group, LLC
ISSN: 0039-7911 print=1532-2432 online
DOI: 10.1080/00397910903291129
POTASSIUM–TERTIARY BUTOXIDE–ASSISTED
ADDITION OF THIOGLICOLIC ACID TO CHALCONE
DERIVATIVES UNDER SOLVENT-FREE CONDITIONS
Mustafa Ceylan, Meliha Burcu Gu¨rdere, Hayreddin Gezegen,
and Yakup Budak
Department of Chemistry, Faculty of Arts and Sciences, Gaziosmanpasa
University, Tokat, Turkey
A series of chalcone derivatives containing thioglicolic acid (4a–j) was prepared by addition
of thioglicolic acid to the chalcones (3a–j) in the presence of KOt-Bu under solvent-free
conditions. The mechanistic pathway of the reaction can be explained by the Michael-type
addition of thioglicolic acid to chalcone derivatives (3a–j).
Keywords: Michael addition; potassium–tertiary butoxide; solvent free; thioglicolic acid
Carbon–sulfur bond formation by conjugate addition of thiols to a,b-unsaturated
carbonyl compounds has versatile applications in chemistry and biology as it plays
critical roles in (i) biosynthesis,[1] (ii) synthesis of bioactive compounds,[2] (iii)
protection of the olefinic double bond of conjugated enones,[3] and (iv) generation
of b-acylvinyl cation[4] and homoenolate anion[5] equivalents. Traditionally, the
1,4-addition of thiols is catalyzed by strong bases such as alkali metal alkoxides,
hydroxides, and amines.[6,7] On the other hand, these reactions were also investigated
using solid acids such as HClO4–SiO2 and different Lewis acids such as InBr3,[9]
[8]
Zn(ClO4)2 ꢀ 6H2O,[10] Hf(OTf)3,[11] Bi(NO3)3,[12] Bi(OTf)3,[13] and Cu(BF4)2;[14] ionic
liquid [pmIm]Br,[15,16] and organocatalyst in solvent-free conditions.[17] Most of the
methods have some disadvantages such as long reaction times, high reaction tem-
peratures, dry or stringent reaction conditions, complex workup procedures, and
moderate yields. This study reports the addition of thioglicolic acid as thiol to chal-
cones in mild conditions in the presence of a small amount of potassium–tertiary
butoxide. This reaction occurs without solvent in a short reaction time at room
temperature and results in excellent yields.
The general synthetic strategy employed to prepare the chalcone derivatives was
based on Claisen–Schmidt condensation, which was reported previously.[18] As shown
in Scheme 1, a series of 11 chalcone derivatives (3a–j) was prepared upon conden-
sation of appropriately substituted acetophenone with furfural in EtOH (Scheme 1).
Received January 14, 2009.
Address correspondence to Mustafa Ceylan, Department of Chemistry, Faculty of Arts and
Sciences, Gaziosmanpasa University, 60110, Tokat, Turkey. E-mail: mceylan@gop.edu.tr
2598

ADDITION OF THIOGLICOLIC ACID TO CHALCONE DERIVATIVES
2599
Scheme 1. Synthesis of chalcones (3a–j) and addition of thioglicolic acid.
After purification of the residue, chalcone derivatives (3a–j) were obtained in the
)
yields of 69–97%. The compounds (3a,[19] 3b,[20] 3c,[20] 3f,[20] 3ı,[21] 3i,[19] and 3j[22]
are known in the literature as the others were synthesized for first time.
1
The structures of chalcone derivatives were evaluated using infrared (IR), H
NMR, and 13C NMR spectroscopic methods.
A series of chalcone derivatives containing thioglicolic acid (4a–j) was prepared
by the addition of thioglicolic acid to chalcones (3a–j). The reaction of chalcones
3a–j with thioglicolic acid in the presence of KOt-Bu (6% mmol) at room tempera-
ture for 3 h gave solely the products (4a–j) of 1,4-addtion of thioglicolic acid in good
yields. When this reaction is carried out in some solvent such as CHCl3 or CH2Cl2,
the yield decreases drastically even at very long reaction times (36 h).
The crude products were purified by filtration on a short silica-gel column
and recrystallized from CHCl3 or CH2Cl2=n-hexane (3:7). In this series, compounds
(4a–j) were produced for the first time according to the literature.
The structures of thioglicolic acid derivatives (4a–j) were also determined on the
1
basis of spectral data (1H NMR, 13C NMR, IR, and elemental analysis). In the H
NMR spectra of 4a–j, the protons of PhCOCH2 led to an AB system that is character-
istic to these compounds.[23] Part A of the AB system was shown as a doublet of doub-
let at d ¼ 3.76–3.65 (J ¼ 17.2–17.6, 7.8–8.4 Hz), and part B was a doublet of doublet at
d ¼ 3.59–3.53 (J ¼ 17.2–17.6, 6.0–6.8 Hz). Moreover, in the 1H NMR spectrum of 4a–j,
the protons of PhCOCH2CH led to a doublet of doublet at d ¼ 4.83–4.66 (J ¼ 7.7–8.2,
6.0–6.9 Hz). All of the spectral data are consistent with the titled compounds.
In summary, a simple, convenient, and efficient method is reported for the
addition of thioglicolic acid to chalcones. Additionally, potassium-tertiary-butoxide
(KOt-Bu) is found as an efficient catalyst for Michael addition of thioglicolic acid to
chalcone derivatives in solvent-free conditions.
EXPERIMENTAL
Melting points were measured on an Electrothermal 9100 apparatus. IR spec-
tra (KBr disc or in CHCl3) were recorded on a Jasco Fourier transform (FT)=IR-430

2600
M. CEYLAN ET AL.
Table 1. Synthesized compounds 4a–j
Entry
Product
Time (h)
Yield (%)
Mp (ꢁC)
1
2
3
92
Viscous oil
3
88
Viscous oil
3
4
3
3
81
94
Viscous oil
Viscous oil
5
6
7
3
3
3
91
85
77
Viscous oil
91
Viscous oil
8
9
3
3
83
93
85
Viscous oil
(Continued )

ADDITION OF THIOGLICOLIC ACID TO CHALCONE DERIVATIVES
2601
Table 1. Continued
Entry
Product
Time (h)
Yield (%)
Mp (ꢁC)
10
3
86
137
145
11
3
79
spectrometer. 1H and 13C NMR spectra were recorded on a Bruker Avance
DPX-400 instrument. Tetramethylsilane (TMS) served as internal standard (d
1
0.00) for H NMR, and CDCl3 (d 77.0) was used for 13C NMR spectroscopy; J
values are given in hertz. The multiplicities of the signals in the H NMR spectra
1
are abbreviated as s (singlet), d (doublet), t (triplet), q (quartet), m (multiplet), br
(broad), and combinations thereof. Elemental analyses were obtained from a LECO
CHNS 932 elemental analyzer.
All column chromatographies were performed on silica gel (60–230 mesh,
Merck).
General Procedure for the Synthesis of Chalcone 3a–j
Furfural (1 mmol) and NaOH (8 mL, 2.5 M NaOH) was added to a solution of
acetophenone derivative (1 mmol) in ethanol (20 mL) at room temperature. The mix-
ture was stirred for 3 h. Then, the mixture was extracted with CHCl3 or CH2Cl2 and
washed with dilute HCl. The organic layer was dried over Na2SO4 and evaporated.
The residue was purified by filtration on a short silica-gel column eluting with CHCl3
or CH2Cl2=n-hexane (3:7) and=or crystallized in CHCl3=n-hexane (3:7) or EtOH.
Data of 3d, 3e, 3g, and 3h
1-(2-Chlorophenyl)-3-(furan-2-yl)prop-2-en-1-one
(3d). Yield:
91%.
Viscous oil. IR: (KBr cmꢂ1) 3126, 2925, 2852, 1621, 1598, 1301, 1284, 1016, 752.
1H NMR (400 MHz, CDCl3): d ¼ 7.53–7.31 (m, 4H, ArH; 1 H, H2), 7.27–7.21 (d,
J ¼ 15.7 Hz, 1H, H7), 7.04–6.99 (d, J ¼ 15.7 Hz, 1H, H6), 6.70–6.69 (d, J ¼ 3.5 Hz,
1H, H4), 6.50–6.48 (dd, J ¼ 3.4 1.8 Hz, 1H, H3). 13C NMR (100 MHz, CDCl3):
d ¼ 193.30, 151.01, 145.59, 139.02, 132.03, 131.40, 131.26, 130.30, 129.30, 126.86,
123.58, 116.88, 112.85. Anal. calcd. for C13H9O2Cl: C, 67.11; H, 3.90. Found: C,
67.40; H, 3.92.
1-(3-Chlorophenyl)-3-(furan-2-yl)prop-2-en-1-one (3e). Yield: 78%. Mp
52–54 ꢁC. IR: (KBr cmꢂ1) 3120, 3068, 2923, 2848, 1679, 1569, 1421, 1284, 1245,

2602
M. CEYLAN ET AL.
1197, 1010, 730. 1H NMR (400 MHz, CDCl3): d ¼ 7.98 (t, J ¼ 1.8 Hz, 1H), 7.87–7.91
(dt, J ¼ 1.3 Hz, 1H), 7.51–7.52 (dd, J ¼ 2.1, 1.1 Hz, 1H), 7.54–7.55 (d, J ¼ 3.5 Hz,
1H), 7.58–7.63 (d, J ¼ 15.3 Hz, 1H), 7.35–7.40 (d, J ¼ 15.3 Hz, 1H), 6.75–6.72 (d,
J ¼ 3.4 Hz, 1H), 6.53–6.51 (dd, J ¼ 3.4, 1.7 Hz, 1H). 13C NMR (100 MHz, CDCl3):
d ¼ 188.34, 151.46, 145.25, 139.71, 134.90, 132.66, 131.30, 129.94, 128.49, 126.48,
118.57, 116.90, 112.84. Anal. calcd. for C13H9O2C: C, 67.11; H, 3.90. Found: C,
67.81; H, 3.97.
1-(2-Bromophenyl)-3-(furan-2-yl)prop-2-en-1-one
(3g). Yield,
70%.
Viscous oil. IR: (KBr cmꢂ1) 3116, 3048, 3008, 1646, 1624, 1600, 1301, 1282, 1014,
970, 754. 1H NMR (400 MHz, CDCl3): d ¼ 7.45–7.06 (m, 4H, ArH), 7.35 (d,
J ¼ 1.5 Hz, 1H, H2), 7.05–7.01 (d, J ¼ 15.8 Hz, 1H, H7), 6.82–6.78 (d, J ¼ 15.8 Hz,
1H, H6), 6.52–6.51 (d, J ¼ 3.5 Hz, 1H, H4), 6.31 (dd, J ¼ 3.4, 1.8 Hz, Hz 1H, H3).
13C NMR (100 MHz, CDCl3): d ¼ 194.03, 150.89, 145.71, 140.98, 133.42, 132.36,
131.41, 129.10, 127.42, 123.37, 119.43, 117.03, 112.95. Anal. calcd. for C13H9O2Br:
C, 56.34; H, 3.27. Found: C, 56.62; H, 3.56.
1-(3-Bromophenyl)-3-(furan-2-yl)prop-2-en-1-one (3h). Yield: 79%. Mp
60–63 ꢁC. IR: (KBr cmꢂ1) 3122, 2981, 2896, 1698, 1683, 1558, 1540, 1508, 1488,
773, 418. 1H NMR (400 MHz, CDCl3): d ¼ 8.13 (t, J ¼ 1.7 Hz, 1H, H14),
7.91–7.87 (dt, J ¼ 1.5 Hz, 1H, H10), 7.68–7.67 (dd as brd, J ¼ 1.9, 1.1 Hz, 1H,
H12), 7.61–7.56 (d, J ¼ 15.3 Hz, 1H, H7), 7.53 (brd, J ¼ 0.6 Hz, 1H, H2), 7.38–7.33
(t, J ¼ 7.7 Hz, 1H, H11), 7.37–7.32 (d, J ¼ 15.7 Hz, 1H, H6), 6.73–6.72 (d, J ¼ 3.1 Hz,
1H, H4), 6.51–6.50 (dd, J ¼ 1.8 Hz, 3.4 Hz 1H, H3).13C NMR (100 MHz, CDCl3):
d ¼ 188.18, 151.44, 145.27, 139.89, 135.56, 131.41, 131.30, 130.19, 126.92, 122.97,
118.51, 116.93, 112.86. Anal. calcd. for C13H9O2Br: C, 56.34; H, 3.27. Found: C,
56.35; H, 3.46.
General Procedure for the Synthesis of 4a–j
A small amount of KOt-Bu (6 mmol) was added to a magnetically stirred mix-
ture of chalcone derivatives (1 mmol) and thioglicolic acid (2 mmol and=or 3 mmol),
and the reaction mixture was stirred at room temperature for 3 h. Then, the mixture
was extracted with CHCl3 and washed with dilute HCl. The organic layer was dried
over Na2SO4, and the solvent was removed under reduced pressure. The crude
product was purified by filtration on a short silica-gel column eluting with CHCl3
or CH2Cl2=n-hexane (3:7) and=or crystallized in CHCl3 or CH2Cl2=n-hexane (3:7).
Data of 4a–j
2-(1-(Furan–2-yl)-3-(2-methoxyphenyl)-3-oxopropylthio)acetic acid (4a).
Yield: 92%. Viscous oil. IR: (CCl4 cmꢂ1): 3716, 3414, 2553, 2219, 1759, 1714, 1689,
1
1641, 1416, 1256, 1195, 1108, 967, 764. H NMR (300 MHz, CDCl3, ppm): d ¼ 9.59
(s, 1H, OH), 7.67 (dd, J ¼ 7.8, 1.1 Hz, 1H, H10), 7.42 (t, J ¼ 0.8 Hz, 1H, H12), 7.35
(m, 1H, H2), 7.00–6.95 (m, 2H, H11, H13), 6.28–6.24 (m, 2H, H3, H4), 4.79 (t,
J ¼ 7.2 Hz, 1H, H6), 3.92 (s, 3 H, OCH3), 3.76 (dd, J ¼ 17.6, 7.9 Hz, 1H, H7), 3.59
(dd, J ¼ 17.6, 6.5 Hz,1H, H7), 3.21 (s, 2H, H15). 13C NMR (75 MHz, CDCl3,
ppm): d ¼ 198.7, 176.5, 151.2, 142.6, 137.1, 134.4, 130.9, 127.6, 124.5, 110.4, 108.8,

ADDITION OF THIOGLICOLIC ACID TO CHALCONE DERIVATIVES
2603
45.8, 45.7, 37.7, 32.6. Anal. calcd. for C16H16O5S: C, 59.99; H, 5.03; S, 10.01. Found:
C, 59.89; H, 4.98; S, 9.87.
2-(1-(Furan–2-yl)-3-(3-methoxyphenyl)-3-oxopropylthio)acetic acid (4b).
Yield: 88%. Viscous oil. IR: (CCl4 cmꢂ1): 3456, 3129, 2544, 2378, 1759, 1676, 1545,
1401, 1286, 1190, 1086, 994, 768. 1H NMR (300 MHz, CDCl3, ppm): d ¼ 9.40 (s, 1H,
OH), 7.54–7.08 (m, 5H, H2, H10, H11, H12, H13), 6.28–6.27 (m, 2H, H3, H4), 4.83
(dd, J ¼ 8.2, 6.0 Hz, 1H, H6), 3.83 (s, 3H, OCH3), 3.75 (dd, J ¼ 17.4, 8.2 Hz, 1H, H7),
3.54 (J ¼ 17.4, 6.0 Hz, 1H, H7), 3.18 (s, 2H, H15). 13C NMR (75 MHz, CDCl3, ppm):
d ¼ 196.0, 172.7, 159.8, 152.3, 142.3, 137.8, 129.6, 120.7, 119.9, 112.2, 110.3, 108.1,
55.4, 41.9, 37.5, 33.0. Anal. calcd. for C16H16O5S: C, 59.99; H, 5.03; S, 10.01. Found:
C, 59.86; H, 4.98; S, 9.93.
2-(1-(Furan–2-yl)-3-(4-methoxyphenyl)-3-oxopropylthio)acetic acid (4c).
Yield: 81%. Viscous oil. IR: (CCl4 cmꢂ1): 3826, 3424, 2946, 2758, 1768, 1740, 1678,
1
1545, 1416, 1265, 1206, 1119, 963, 747. H NMR (300 MHz, CDCl3, ppm): d ¼ 8.52
(s, 1H, OH), 7.94 (d, J ¼ 8.9 Hz, 2H, AA0, H10, H13), 7.35 (t, J ¼ 1.3 Hz, 1H, H2),
6.93 (d, J ¼ 8.9 Hz, 2H, XX0, H11, H12), 6.29 (d, J ¼ 1.3 Hz, 2H, H3, H4), 4.83
(dd, J ¼ 8.1, 6.2 Hz, 1H, H6), 3.86 (s, 1H, OCH3), 3.71 (dd, J ¼ 17.2, 8.1 Hz, 1H,
H7), 3.50 (dd, J ¼ 17.2, 6.2 Hz, 1H, H7), 3.20 (s, 2H, H15). 13C NMR (75 MHz,
CDCl3, ppm): d ¼ 194.7, 173.4, 163.7, 152.4, 142.3, 130.4, 129.5, 113.8, 110.2,
108.1, 55.5, 41.4, 37.8, 33.0. Anal. calcd. for C16H16O5S: C, 59.99; H, 5.03; S,
10.01. Found: C, 59.66; H, 5.02; S, 9.87.
2-(3-(2-Cholorophenyl)-1-(furan–2-yl)-3-oxopropylthio)acetic acid (4d).
Yield: 94%. Viscous oil. IR: (CCl4 cmꢂ1): 3326, 2435, 1719, 1700, 1698, 1673,
1586, 1482, 1286, 1211, 1008, 961, 793. 1H NMR (300 MHz, CDCl3, ppm):
d ¼ 9.57 (s, 1H, OH), 7.57–7.28 (m, 5H, H2, H10, H11, H12, H13), 6.30–6.28 (m,
2H, H3, H4), 4.76 (dd, J ¼ 14.6, 7.6 Hz,1 H, H6), 3.73 (dd, J ¼ 17.3, 7.8 Hz, 1H,
H7), 3.56 (J ¼ 17.3, 6.8 Hz, 1H, H7), 3.22 (s, 2H, H15).13C NMR (75 MHz, CDCl3,
ppm): d ¼ 199.2, 176.1, 151.7, 142.6, 138.5, 132.2, 131.0, 130.5, 129.3, 127.0, 110.3,
108.5, 45.9, 38.0, 32.7. Anal. calcd. for C15H13ClO4S: C, 55.47; H, 4.03; S, 9.87.
Found: C, 55.40; H, 3.92; S, 9.77.
2-(3-(3-Cholorophenyl)-1-(furan–2-yl)-3-oxopropylthio)acetic acid (4e).
Yield: 91%. Viscous oil. IR: (CCl4 cmꢂ1): 3432, 2835, 1879, 1724, 1679, 1663,
1516, 1413, 1263, 1200, 1012, 991, 755. 1H NMR (300 MHz, CDCl3, ppm):
d ¼ 10.28 (s, 1H, OH), 8.07 (d, J ¼ 1.7 Hz, 1H, H14,), 7.87 (dt, J ¼ 7.8, 1.3 Hz, 1H,
H10), 7.69 (dq, 7.8, 1.0 Hz, 1H, H12), 7.37–7.35 (m, 2H, H11, H2), 6.31 (d,
J ¼ 1.2 Hz, 2H, H3, H4), 4.83 (dd, J ¼ 7.8, 6.4 Hz, 1H, H6), 3.72 (dd, J ¼ 17.5,
7.8 Hz, 1H, H7), 3.53 (dd, J ¼ 17.5, 6.3 Hz, 1H, H7), 3.23 (s, 2H, H15). 13C NMR
(75 MHz, CDCl3, ppm): d ¼ 194.8, 176.1, 151.7, 142.6, 138.0, 136.3, 131.2, 130.3,
126.6, 123.1, 110.3, 108.5, 41.8, 37.6, 32.8. Anal. calcd. for C15H13ClO4S: C, 55.47;
H, 4.03; S, 9.87. Found: C, 55.34; H, 3.84; S, 8.99.
2-(3-(4-Cholorophenyl)-1-(furan–2-yl)-3-oxopropylthio)acetic acid (4f).
Yield: 85%. Mp 91 ꢁC. IR: (CCl4 cmꢂ1): 3621, 3244, 2654, 2315, 1763, 1726, 1698,
1
1564, 1421, 1276, 1200, 1108, 982, 784. H NMR (300 MHz, CDCl3, ppm): d ¼ 9.5
(s, 1H, OH), 10.5 (s, 1H, OH), 7.91 (d, J ¼ 6.7 Hz, 2H, AA0, H10, H14), 7.45 (d,

2604
M. CEYLAN ET AL.
J ¼ 6.7 Hz, 2H, XX0, H11, H12), 7.38–7.37 (m, 1H, H2), 6.31–6.30 (m, 2H, H3, H4),
4.84 (dd, J ¼ 7.8, 6.4 Hz, 1H, H6), 3.74 (dd, J ¼ 17.4, 7.8 Hz, 1H, H7), 3.55 (dd,
J ¼ 17.4, 6.4 Hz, 1H, H7), 3.24 (s, 2H, H15). 13C NMR (75 MHz, CDCl3, ppm):
d ¼ 194.9, 175.9, 151.7, 142.6, 140.0, 134.6, 129.5, 129.0, 110.3, 108.5, 41.7, 37.7,
32.8. Anal. calcd. for C15H13ClO4S: C, 55.47; H, 4.03; S, 9.87. Found: C, 55.40;
H, 4.00; S, 9.72.
2-(3-(2-Bromophenyl)-1-(furan–2-yl)-3-oxopropylthio)acetic acid (4g).
Yield: 77%. Viscous oil. IR: (CCl4 cmꢂ1): 3232, 2697, 2318, 1766, 1736, 1685,
1
1541, 1329, 1376, 1210, 1185, 993, 752. H NMR (300 MHz, CDCl3, ppm): d ¼ 9.7
(s, 1H, OH), 7.80 (dd, J ¼ 7.6, 0.9 Hz, 1H, H10), 7.37–7.31 (m, 4H, H2, H11, H12,
H13), 6.31–6.29 (m, 2H, H3, H4), 4.78 (dd, J ¼ 7.8, 6.9 Hz, 1H, H6), 3.70
(J ¼ 17.3, 7.9 Hz, 1H, H7), 3.54 (J ¼ 17.3, 6.8 Hz, 1H, H7), 3.22 (s, 2H, H15). 13C
NMR (75 MHz, CDCl3, ppm): d ¼ 199.9, 176.2, 151.5, 142.6, 140.7, 133.7, 132.0,
128.8, 127.5, 118.7, 110.3, 108.6, 45.7, 37.9, 32.7. Anal. calcd. for C15H13BrO4S:
C, 48.79; H, 3.55; S, 8.68. Found: C, 48.40; H, 3.38; S, 8.61.
2-(3-(3-Bromophenyl)-1-(furan–2-yl)-3-oxopropylthio)acetic acid (4h).
Yield: 83%. Mp 85 ꢁC. IR: (CCl4 cmꢂ1): 3342, 2974, 2188, 1754, 1719, 1698, 1532,
1
1387, 1205, 1152, 945, 786. H NMR (300 MHz, CDCl3, ppm): d ¼ 11.02 (s, 1H,
OH), 7.91 (d, J ¼ 1.7 Hz, 1H, H14), 7.83 (d, J ¼ 7.8 Hz, 1H, H10), 7.56–7.53 (m,
1H, H12), 7.44–7.37 (m, 2H, H11, H2), 6.31 (d, J ¼ 0.6 Hz, 2H, H3, H4), 4.84 (dd,
J ¼ 7.7, 6.5 Hz, 1H, H6), 3.74 (dd, J ¼ 17.5, 7.8 Hz, 1H, H7), 3.54 (dd, J ¼ 17.5,
6.3 Hz, 1H, H7), 3.24 (s, 2H, H15). 13C NMR (75 MHz, CDCl3, ppm): d ¼ 194.9,
176.4, 151.7, 142.6, 137.8, 135.0, 133.4, 130.0, 128.2, 126.2, 110.3, 108.5, 41.8,
37.6, 32.8. Anal. calcd. for C15H13BrO4S: C, 48.79; H, 3.55; S, 8.68. Found: C,
48.65; H, 3.52; S, 8.77.
2-(3-(4-Bromophenyl)-1-(furan–2-yl)-3-oxopropylthio)acetic acid (4i).
Yield: 93%. Viscous oil. IR: (CCl4 cmꢂ1): 3352, 2743, 2186, 1798, 1765, 1653,
1541, 1325, 1369, 1220, 1153, 981, 788. 1H NMR (300 MHz, CDCl3, ppm):
d ¼ 10.7 (s, 2H, OH), 7.82 (d, J ¼ 8.5 Hz, 2H, AA0, H10, H13), 7.62 (d, J ¼ 8.5 Hz,
2H, XX0, H11, H12), 7.37 (t, J ¼ 1.3 Hz, 1H, H2), 6.31 (d, J ¼ 1.3 Hz, 2H, H3,
H4), 4.84 (dd, J ¼ 7.7, 6.5 Hz, 1H, H6), 3.73 (dd, J ¼ 17.4, 7.8 Hz, 1H, H7), 3.53
(dd, J ¼ 17.4, 6.4 Hz, 1H, H7), 3.23 (s, 2H, H15). 13C NMR (75 MHz, CDCl3,
ppm): d ¼ 195.2, 176.3, 151.7, 142.6, 135.0, 132.0, 129.6, 128.8, 110.3, 108.5, 41.6,
37.7, 32.8. Anal. calcd. for C15H13BrO4S: C, 48.79; H, 3.55; S, 8.68. Found: C,
48.74; H, 3.47; S, 8.59.
2-(1-(Furan–2-yl)-3-(2-hydroxyphenyl)-3-oxopropylthio)acetic acid (4i).
Yield: 86%. Mp 137 ꢁC. IR: (CCl4 cmꢂ1): 3423, 2375, 2339, 1714, 1702, 1695,
1
1637, 1508, 1490, 1486, 1282, 1218, 1010, 981, 771. H NMR (400 MHz, CDCl3,
ppm): d ¼ 12.0 (s, 1H, OH), 7.80 (dd, J ¼ 8.0, 1.4 Hz, 1H, H10,), 7.41–7.36 (m,
1H, H12), 7.28 (dd, J ¼ 1.8, 0.9 Hz, 1H, H2), 6.85–6.80 (m, 2H, H11, H13),
6.22–6.19 (m, 2H, H3, H4), 4.74 (dd, J ¼ 8.1, 6.1 Hz, 1H, H6), 4.54 (s, 1H, OH),
3.73 (dd, J ¼ 17.4, 8.1 Hz, 1H, H7), 3.58 (dd, J ¼ 17.4, 6.2 Hz, 1H, H7), 3.10 (s,
2H, H15). 13C NMR (100 MHz, CDCl3, ppm): d ¼ 207.7, 176.5, 167.5, 157.6,
141.8, 135.4, 124.4, 123.3, 115.5, 113.0, 46.7, 42.4, 37.7, 35.2. Anal. calcd. for
C15H14O5S: C, 58.81; H, 4.61; S, 10.47. Found: C, 58.78; H, 4.55; S, 10.23.

ADDITION OF THIOGLICOLIC ACID TO CHALCONE DERIVATIVES
2605
2-(1-(Furan–2-yl)-3-(4-hydroxyphenyl)-3-oxopropylthio)acetic acid (4j).
Yield: 79%. Mp 145 ꢁC IR: (CCl4 cmꢂ1): 3416, 2254, 2239, 1718, 1716, 1698, 1643,
1521, 1486, 1276, 1211, 1003, 989, 768. 1H NMR (300 MHz, CDCl3, ppm):
d ¼ 12.4 (s, 1H, OH), 10.5 (s, 1H, OH), 7.84 (d, J ¼ 8.7 Hz, 2H, AA0, H10, H13),
7.50 (d, J ¼ 0.9 Hz, 1H, H2), 6.82 (d, J ¼ 8.6 Hz, 2H, XX0, H11, H12), 6.31 (d,
J ¼ 1.8 Hz, 1H, H3), 6.26 (d, J ¼ 3.0 Hz, 1H, H4), 4.66 (dd, J ¼ 8.2, 6.0 Hz, 1H,
H6), 3.65 (dd, J ¼ 17.3, 8.4 Hz, 1H, H7), 3.57 (dd, J ¼ 17.3, 6.0 Hz, 1H, H7), 3.20
(s, 2H, H15). 13C NMR (75 MHz, CDCl3, ppm): d ¼ 194.7, 171.7, 162.7, 153.6,
142.6, 131.0, 128.2, 115.6, 110.7, 107.6, 40.5, 39.4, 33.0. Anal. calcd. for
C15H14O5S: C, 58.81; H, 4.61; S, 10.47. Found: C, 58.78; H, 4.58; S, 10.38.
ACKNOWLEDGMENT
The authors are indebted to the Technical Research Council of Turkey (Grant
TUBITAK-106T103) for financial support of this work.
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