Synthesis and reactivity of 1-aryl-9h-thieno[3,4-b]chromon-9-ones

Article abstract of DOI:10.1039/b9nj00237e

Methods were developed for the synthesis of 1-aryl-9H-thieno[3,4-b]chromon- 9-ones based on the reaction of bromo and dibromo derivatives of 2-methyl-4H-chromon-4-one with thioacetamide in DMF. The thienochromones were modified and their fluorescence prop

Full text of DOI:10.1039/b9nj00237e

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PAPER
www.rsc.org/njc | New Journal of Chemistry
Synthesis and reactivity of 1-aryl-9H-thieno[3,4-b]chromon-9-onesw
Mikhail M. Krayushkin,a Konstantin S. Levchenko,a Vladimir N. Yarovenko,a
Ludmila V. Christoforova,a Valery A. Barachevsky,b Yury A. Puankov,b
Tatyana M. Valova,b Olga I. Kobelevab and K. Lyssenkoc
Received (in Victoria, Australia) 5th June 2009, Accepted 23rd July 2009
First published as an Advance Article on the web 2nd September 2009
DOI: 10.1039/b9nj00237e
Methods were developed for the synthesis of 1-aryl-9H-thieno[3,4-b]chromon-9-ones based on the
reaction of bromo and dibromo derivatives of 2-methyl-4H-chromon-4-one with thioacetamide in
DMF. The thienochromones were modified and their fluorescence properties were studied.
Bis(thienochromones) were synthesized by the reaction of thienochromones with ketoaldehydes.
are unknown. The development of methods for the synthesis
Introduction
of this type of compounds and investigation of their physico-
The chromone fragment is involved in many natural
chemical properties present interesting problems.
compounds with a wide spectrum of biological activities.
Chromones fused to the thiophene ring (3) have been
Many chromones have fluorescence properties and have found
investigated as local anesthetics or central nervous system
use as sensors for microscopy studies of proteins, micro-
stimulators.13 The synthesis of thieno[3,4-b]chromone by
organelles, and cells.1a–c Chromones have been studied as
reaction of a 3-acyl-2-(bromomethyl)chromone with thio-
antioxidants,2 agents for wound3 and ulcer healing,4 immune
acetamide was described for one example 11a.14
stimulators,5 and anti-HIV agents.6 Heteroarylchromones
In the present study, we synthesized a wide range of
(Fig. 1) are of great interest for the design of various drugs
3-acyl-2-methylchromones 7 according to the procedure developed
and fluorescent labels for biological substrates. Lupinalbin A
earlier15 (Scheme 1), studied the cyclization of their bromo
(phytoestrogen),7 lisetin (analog of lupinalbin A) isolated from
derivatives, and showed that thieno[3,4-b]chromones thus
plants of the Leguminosae family (2),8 and pyralomicins, which
prepared can be functionalized.
were isolated from the microorganism Microtetraspora spiralis
and have antitumor and antibacterial properties,9 belong to
Earlier, it has been shown that monobromo derivative 9a is
formed by the addition of one equivalent of bromine to a hot
natural heterocycle-annelated chromones. Synthetic hetaryl-
(60–70 1C) solution of chromone 7a in CCl4. However,
we found that, under these conditions, the reaction affords
chromones have found use as anti-ulcer drugs (Aphthasol)
(1)10 and drugs for the asthma treatment11 and are considered
as antiallergic agents.12
compound 9a along with dibromo derivative 8a as
a
by-product. It is known that the reactions of dibromo- and
mono-bromomethyl moieties with nucleophiles can give the
same products. Hence, we also examined the possibility of
using dibromo derivatives 8a–c in the step of cyclization to
thienochromones.
In the above-described pyrrole, thiophene or furan containing
compounds, the five-membered heterocyclic moiety is generally
fused to chromone forming [2,3-b] or [3,2-b] derivatives.
[3,4-b]Chromone derivatives are scarce and their properties
a N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of
Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation.
E-mail: mkray@mail.ioc.ac.ru; Fax: +7 (495) 135 5328
b Photochemistry Center, Russian Academy of Sciences,
7a ul. Novatorov, 119421 Moscow, Russian Federation
c N. Nesmeyanov Institute of Organoelement Compounds, Russian
Academy of Sciences, 28 ul. Vavilova, 119991 Moscow, Russian
Federation
Earlier, the cyclization of monobromo derivative 9a
was carried out with the use of an ethanolic solution of
thioacetamide in the presence of a small excess of sodium
acetate.14 We showed that, in the presence of sodium acetate,
the reaction giving rise to thienochromone 11a is accompanied
by side reactions both in ethanol and DMF. Compound 9a
reacts with sodium acetate under reflux in an ethanolic
solution or under cooling in DMF, resulting in the replacement
w CCDC reference number 742366. For crystallographic data in CIF
or other electronic format see DOI: 10.1039/b9nj00237e
Fig. 1
ꢀc
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Scheme 1 Reagents and conditions: (i) ArC(O)Cl, pyridine, r.t. 40–60 min; (ii) t-BuOK, DMF, 0 1C; (iii) (RCO)2O, RCOONa, reflux, 30–60 min.
a mixture of mono- and di-bromo derivatives can be used in
the heterocyclization reactions with thioacetamide.
The possibility of modifying thienochromones was
demonstrated with several examples.
Halogen-containing biologically active chromones were
described in the literature. In particular, pyrrolomycins con-
taining the 2-chloropyrrolochromone system are antibiotics.9
However, halogen derivatives of thienochromone are unknown.
The bromination of compound 11a in dichloromethane at
room temperature affords bromo derivative 10a, whereas the
reaction with iodine in dichloromethane in the presence of
mercury oxide gives iodo derivative 13 (Scheme 4).
Scheme 2 Reagents and conditions: (i) AcONa, DMF, 0–40 1C;
(ii) AcONa, EtOH, reflux.
of bromine with the acetate fragment to give compound 12
(Scheme 2). An increase in the temperature of the reaction
mixture in DMF leads to resinification of the products.
We found that the cyclisation to the thienochromone
proceeded easily in DMF without the addition of sodium
acetate. Heating of monobromo derivatives 9a–h in DMF at
60–80 1C in the presence of excess thioacetamide for 1 h
affords thienochromones 11a–h in 60–80% yields.
The aldehyde group is
a convenient substituent for
modifications of chromones. However, we failed to introduce
The reactions of chromones 7a, 7b, 7d with a twofold excess
of bromine in boiling CCl4 were shown14 to give only dibromo
derivatives 8a, 8b, 8d (Scheme 3). The reactions of these
compounds with thioacetamide in DMF at 80–100 1C are
accompanied by elimination of two bromine atoms to give the
corresponding thienochromones 11a–h also in good yields. It
should be noted that the component 10 is not formed. Hence,
Scheme 4 Reagents and conditions: (i) Br2, CH2Cl2, r.t., 1 h; (ii) HgO,
I2, benzene, 1 h.
Scheme 3 Reagents and conditions: (i) Br2 (2.2 equiv.), CCl4, reflux, 1.5–2 h; (ii) Br2 (1.1 equiv.), CCl4, heating 60–70 1C, 30 min; (iii) CH3C(S)NH2
(2.2 equiv.), DMF, 80–100 1C, 60–90 min; (iv) CH3C(S)NH2 (1.5 equiv.), DMF, 70–80 1C, 40–60 min.
ꢀc
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with one equivalent of ketoaldehydes 17 in the presence of tin
tetrachloride (Scheme 7). We failed to isolate intermediate 18,
which could be formed in the reaction. It should be noted that
the formation of this type of compounds in the reactions
with ketoaldehydes has not been documented earlier in the
literature.
The structures of compounds 19a–e were established by
spectroscopy and elemental analysis. Bis(thienochromone) 19a
was studied by X-ray diffraction (Fig. 2).
Scheme 5 Reagents and conditions: (i) tin(IV) chloride, 1,2-dichloro-
According to X-ray diffraction data, the compound 19a in
the crystal exists in a keto-form with the C(43)–O(44) bond
length being 1.224(3) A and all covalent bonds formed by the
C(22) atom (1.512(3)–1.547(3) A) are close to ordinary C–C
ones (Fig. 3). As the consequence, there is no conjugation
between the heterocyclic moieties in 19a. The CQO double
bond is almost coplanar with one of the heterocycles, namely
C(23)–S(35), with the value of the pseudo-torsion angle
ethane, ice/brine cooling, 1,5 h.
the aldehyde group at the free position of the thiophene ring in
compounds 11a–f with the use of lithium diisopropylamide
and DMF or a mixture of phosphorus oxychloride and DMF.
This is indicative of a substantial electron-withdrawing effect
of the substituents on the thiophene ring in thienochromones.
We succeeded in performing formylation of 11a–f with
dichloromethyl ether in the presence of SnCl4 (Scheme 5).
The presence of the aldehyde group allows the further
modification of the thienochromones, in particular, the
synthesis of azomethines or unsaturated ketones (Scheme 6).
We examined the possibility of synthesizing compounds
19a–e. The presence of two thienochromyl moieties in the
molecules should enhance the fluorescence properties of the
compounds. In addition, certain analogs, containing the 2,2-
diarylethanone moiety (e.g. PD85639) have a local anesthetic
effect due to selective sodium channel blockade in cells.16
Bis(thienochromones) 19a–e were synthesized by the reaction
of two equivalents of thiophene-containing derivatives 11a–f
Scheme 6 Reagents and conditions: (i) EtOH, reflux; (ii) KOH (40% aq.),
EtOH, r.t. (in case of 16a an acetone–ethanol mixture (1 : 1) and ice
cooling are used).
Fig. 2 The general view of 19a with representation of atoms via
thermal ellipsoids (p = 50%).
Scheme 7 Reagents and conditions: (i) tin(IV) chloride, CH2Cl2, r.t., 1 h.
ꢀc
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Fig. 4 Absorption spectra (1) and fluorescence spectra (2) of a
solution of compound 11a in toluene. The fluorescence excitation
wavelength is 375 nm.
Fig. 3 The stacking interaction in crystal of 19a.
S(35)C(23)C(43)O(44) equal to 12.71. Such disposition of
CQO bond leads to the formation of the shortened intra-
molecular contact O(44)ꢁꢁꢁS(35); the corresponding interatomic
distance is equal to 2.659(2) A. Considering its directionality—
the bond angle O(44)S(35)C(34) is 169.5(1)1—we can expect
the presence of a charge transfer from the lone pair on
oxygen to the antibonding C–S orbital. However, comparing
the similar S(35)–C(34) and S(4)–C(15) bonds clearly shows
that, despite the possible charge transfer, the former is
shorter (1.717(2) vs. 1.728(2) A). At the same time, we cannot
exclude that this variation of S–C bond lengths is caused by
crystal packing effects. Indeed, the C(23)–S(35) fragment
in the crystal of 19a participates in the formation of an
intermolecular stacking interaction with its symmetry-related
analogue (Fig. 3). This contact is rather strong with the
smallest Cꢁ ꢁ ꢁC distance of 3.396(2) A and a pronounced
overlap of p-systems.
Fig. 5 Absorption spectra (1) and fluorescence spectra (2) of a
solution of compound 11c in toluene. The fluorescence excitation
wavelength is 410 nm.
To study the relationship between the thienochromone
structure, on the one hand, and the biological activity and
the fluorescence properties of the compounds, on the other
hand, we reduced the carbonyl group in compound 11a
(Scheme 8).
Principal spectral/luminescent characteristics of the synthe-
sized compounds are presented in Fig. 4–6 and Table 1.
These data were compared with the corresponding para-
meters of compound 11a, whose spectral/luminescent charac-
teristics are presented in Fig. 4 and Table 1.
Fig. 6 Absorption spectra (1) and fluorescence spectra (2) of a
solution of compound 16b in toluene. The fluorescence excitation
wavelength is 420 nm.
Scheme 8
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Table
1
Spectral/luminescent characteristics of the synthesized
and an increase in the fluorescence intensity with increasing
compoundsa
electron-withdrawing ability of the substituents.
The introduction of the formyl group (compound 14a) leads
to a sharp decrease in the fluorescence intensity even compared
to compound 11a, which is accompanied by a bathochromic
shift of the fluorescence band.
Structure labsmax/nm (Dini
)
10ꢃ4e/l cmꢃ1 Mꢃ1 lflumax/nm Iflu/a.u.
10
11a
11b
380 (0.28)
370 (0.62)
324 (0.24)
406 (0.32)
311 (0.40)
326 (0.60)
410 (0.71)
375 (0.21)
383 (0.36)
380 (0.55)
320 (0.29)
380 (0.37)
315 (0.61)
339 (0.43)
405 (0.46)
320 (0.54)
367 (0.56)
415 (0.80)
318 (0.95)
360 (0.89)
420 (1.30)
304 (0.32)
0.70
1.55
0.60
0.80
1.00
1.50
1.78
0.52
0.90
1.38
0.72
0.92
1.52
1.08
1.15
1.35
1.40
2.00
2.38
2.22
3.25
0.80
470
435
40
30
485
470
605
The replacement of the formyl group by the ethylenic ketone
(compound 16a), ethylenic ketophenol (compound 16c), or
ethylenic ketothiophene (compound 16b) group causes batho-
chromic shifts of the absorption and fluorescence maxima
in accordance with an increase in the number of conjugated
bonds. However, the fluorescence intensity of these compounds
is lower than that of compounds 11b, 11c and 11e, which may
be associated with a partial photoexcitation energy loss for
the cis–trans isomerization of these substituents and,
consequently, with a decrease in the fluorescence efficiency.
These compounds, like compound 11c, are characterized by
the complex absorption spectrum in the UV region (Fig. 6).
A comparative analysis of the spectral/luminescent charac-
teristics of the newly synthesized compounds shows that the
positions of the absorption and fluorescence bands, as well as
the fluorescence intensity, substantially depend on the nature
of the substituents in the thiophene moiety. The compounds
containing the thienyl or furyl substituent in the thiophene
moiety of chromones have the best fluorescence properties.
The structure–property relationships revealed in the present
study suggest possibilities for a further improvement of the
spectral/luminescent characteristics of this class of compounds
by the directed synthesis.
11c
3915
11d
11h
13
460
472
473
458
30
245
100
5
14a
16a
16c
16b
505
510
510
370
120
60
100
225
20
a
max
max
labs
and lflu
are the wavelengths of the absorption and
fluorescence maxima, respectively, Dini is the absorbance at the
absorption maxima, e is the molar extinction coefficient, and Iflu is
the relative fluorescence intensity.
As can be seen from Fig. 4, compound 11a is characterized
by an intense structured absorption band with a maximum at
370 nm. The excitation of compound 11a at the absorption
maximum of this compound causes the fluorescence with the
maximum intensity at 435 nm.
Experimental
The disruption of the conjugation due to reduction of the
carbonyl group to an alcohol group (compound 20) leads to a
strong hypsochromic shift (by 65 nm) of the absorption
and fluorescence maxima (to 304 and 370 nm, respectively).
However, this is accompanied by an increase in the fluorescence
intensity.
General procedures
1H NMR spectra were recorded on Bruker AM-300, Bruker
AC-200 (200 MHz) and WM-250 (250 MHz) instruments in
DMSO-d6 or CDCl3. Mass spectra were obtained on a
Varian MAT CH-6 instrument using a direct inlet system;
the ionization energy was 70 eV; the acceleration voltage was
1.75 kV. The melting points were measured on a Boetius
hot-stage apparatus and are uncorrected. The reaction
mixtures were analyzed and the purity of all products was
checked by TLC on Merck Silica gel 60 F254 UV-254 plates.
Compounds 17 were prepared from corresponding acetyl
derivatives according to literature methods.17
The introduction of the thienyl (compound 11b) or furyl
(compound 11c) substituent instead of the phenyl group causes
substantial bathochromic shifts of both the absorption and
fluorescence bands, which is accompanied by a sharp increase
in the fluorescence intensity, particularly for compound 11c
containing the furan substituent. Apparently, this is attributed
to the stronger electron-donating ability of these substituents
compared to the phenyl-substituted compound. The absorption
spectra of these compounds show short-wavelength absorption
bands apparently assigned to the nature of these groups (Fig. 5).
An analogous strong bathochromic shift is observed for the
fluorescence band of compound 11a after the introduction of
the weak electron-donating methyl group into the thiophene
moiety (compound 11d), which is accompanied by a decrease
in the fluorescence intensity.
Spectral/luminescent study of synthesized compounds were
carried out in toluene (Aldrich) solutions at 25 1C. A Cary
50 bio. Spectrophotometer (Varian) was used to measure the
absorption spectra; the concentration of compounds in
solution was C = 2 ꢂ 10ꢃ4 mol dmꢃ3. Absorption spectra
were measured in quartz cuvettes with thickness 0.2 cm.
Fluorescence spectra were taken using quartz cuvettes
(thickness
1 cm) on a Cary Eclipse spectrofluorimeter
(Varian). The working concentrations of compounds in solu-
tion was C = 4 ꢂ 10ꢃ5 mol dmꢃ3
General procedure for acylation of 20-hydroxyacetophenones (5)
In the presence of electron-withdrawing substituents either
in the phenyl (compound 11d) or thiophene (compounds 9a
and 13) moieties, weak fluorescence is observed; the fluorescence
intensity of these compounds is comparable with that of
unsubstituted compound 11a (Table 1). This is accompanied
by a slight bathochromic shift of the fluorescence maximum
.
Freshly distilled anhydrous pyridine (5 ml) was added to
20-hydroxyacetophenone or 20-hydroxy-50-methylacetophenone
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(25 mmol) under cooling with iced water. Then aromatic acid
chloride (30 mmol) was added dropwise at o25 1C. The
mixture was allowed to stand for 40–60 min at room temperature
and then poured into a cold 3% hydrochloric acid solution.
The precipitate that formed was filtered off, dried, and
recrystallized from ethanol.
solution. The product that precipitated was filtered off, dried
in air, and recrystallized from ethanol.
1-(2-Hydroxyphenyl)-3-phenylpropane-1,3-dione (6a). Yield
83%, mp = 121–122 1C (EtOH) (lit. 122 1C22) 1H NMR
(CDCl3)
d 15.55 (s, 1HOH), 12.10 (s, 1HOH), 7.95
(d, J = 6.6 Hz, 2HAr), 7.80 (d, J = 7.9 Hz, 1HAr),
7.40–7.70 (m, 4HAr), 6.80–7.10 (m, 3HAr). Anal. Calc. for
C15H12O3: C, 74.99; H, 5.03. Found: C, 74.85; H, 4.96%.
2-Acetylphenyl benzoate (5a). Yield 90%, mp = 87–88 1C
(EtOH) (lit. 87–88 1C18). 1H NMR (CDCl3) d 8.23 (d,
J = 7.5 Hz, 2HAr), 7.87 (d, J = 7.8, Hz, 1HAr), 7.72–7.50
(m, 4HAr), 7.39 (t, J = 7.5, 1HAr), 7.25 (d, J = 7.7 Hz, 1HAr),
2.57 (s, 3HMe). Anal. Calc. for C15H12O3: C 74.99; H 5.03.
Found: C 75.16; H 4.98%.
1-(2-Hydroxyphenyl)-3-(4-chlorophenyl)propane-1,3-dione (6b).
Yield 66%, mp = 125–127 1C (EtOH) (lit. 122–124 1C19).
1H NMR (CDCl3) d 15.52 (s, 1HOH), 12.00 (s, 1HOH) 7.88
(d, J = 9.3 Hz, 2HAr), 7.78 (d, J = 9.2 Hz, 1HAr) 7.5 (m, 3HAr),
6.69–7.05 (m, 2HAr), 6.81 (s, 1H). Anal. Calc. for C15H11ClO3:
C 65.59; H 4.04; Cl 12.91. Found: C, 65.45; H, 3.99; Cl,
12.80%.
2-Acetylphenyl 4-chlorobenzoate (5b). Yield 90%,
1
mp = 93–94 1C (EtOH) (lit 92–93 1C19). H NMR (CDCl3)
d 8.16 (d, J = 8.4 Hz, 2HAr), 7.88 (d, J = 7.7 Hz, 1HAr),
7.22–7.65 (m, 5HAr), 2.55 (s, 3HMe). MS m/z 274, 183, 142,
141, 140, 139, 121, 113, 111. Anal. Calc. for C15H11ClO3: C
65.59; H 4.04; Cl 12.91. Found: C 65.47; H 3.38; Cl 12.80%.
1-(2-Hydroxyphenyl)-3-(furan-2-yl)propane-1,3-dione (6c).
1
Yield 70%, mp = 85–87 1C (EtOH) (lit. 88 1C23). H NMR
(CDCl3) d 15.12 (s, 1HOH), 12.11 (s, 1HOH), 7.80 (d, J = 8.1
Hz, 1HAr), 7.65 (s, 1HAr), 7.50 (t, J = 7.8 Hz, 1HAr), 7.19
(d, J = 3.5 Hz, 1HAr), 6.89–7.02 (m, 2HAr), 6.6.79 (s, 1H), 6.61
(m, 1HAr). Anal. Calc. for C13H10O4: C 67.82; H 4.38. Found:
C, 67.68; H 4.31%.
2-Acetylphenyl furan-2-carboxylate (5c). Yield 80%,
mp = 90–92 1C (EtOH) (lit. 92 1C20). 1H NMR (CDCl3)
d 7.87 (d, J = 7.7 Hz, 1HAr), 7.7 (s, 1H), 7.58 (t, J = 7.62 Hz,
1HAr), 7.25–7.45 (m, 3HAr), 6.63 (dd, J = 3.2, 1.4 Hz, 1HAr),
2.58 (s, 3HMe). Anal. Calc. for C13H10O4: C 67.82; H 4.38.
Found: C 67.69; H 4.30%.
1-(2-Hydroxyphenyl)-3-(thiophen-2-yl)propane-1,3-dione (6d).
Yield 67%, mp = 90–92 1C (EtOH) (lit. 86–87 1C14). 1H
NMR (CDCl3) d 11.30 (s, 1HOH), 11.00 (s, 1HOH), 7.80–8.10
(m, 3HAr), 7.40–7.60 (m, 1HAr), 7.25–7.35 (m, 1HAr),
6.90–7.00 (m, 2HAr), 4.80 (s, 1H). Anal. Calc. for
C13H10O3S: C, 63.40; H, 4.09; S, 13.02. Found: C, 63.50; H,
4.02; S, 13.13%.
2-Acetylphenyl thiophene-2-carboxylate (5d). Yield 86%,
mp = 113–114 1C (EtOH) (lit. 112–114 1C21). 1H NMR (CDCl3)
d 8.05 (d, J = 3.3 Hz, 1HAr), 7.87 (dd, J = 7.7, 1.3 Hz, 1HAr),
7.70 (d, J = 4.5 Hz, 1HAr), 7.60 (dt, J = 7.7, 1.5 Hz, 1HAr),
7.38 (t, J = 7.4 Hz, 1HAr), 7.17–7.20 (m, 2HAr), 2.59
(s, 3HMe). Anal. Calc. for C13H10O3S: C 63.40; H 4.09; S
13.02. Found: C 63.50; H 3.98; S 13.13%.
1-(2-Hydroxy-5-methylphenyl)-3-(thiophen-2-yl)propane-1,3-
dione (6e). Yield 57.5%, mp 84–86 1C (EtOH). 1H NMR
(CDCl3) d 15.75 (s, 1HOH), 11.70 (s, 1HOH), 7.50–7.80 (m,
3HAr), 6.70–7.35 (m, 3HAr), 4.45 (s, 1H), 2.36 (s, 3HMe). Anal.
Calc. for C14H12O3S: C, 64.60; H, 4.65; S, 12.32. Found:
C 64.45; H 4.57; S 12.47%.
2-Acetyl-4-methylphenyl thiophene-2-carboxylate (5e). Yield
84%, mp = 90–91 1C (EtOH). 1H NMR (CDCl3) d 8.0
(d, J = 3.6 Hz, 1HAr), 7.63–7.71 (m, 2HAr), 7.37 (d, J = 8.2
Hz, 1HAr), 7.1–7.2 (m, 2HAr), 2.55 (s, 3HMe), 2.42 (s, 3HMe).
Anal. Calc. for C14H12O3S: C 64.60; H 4.65; S 12.32. Found:
C, 64.50; H, 4.58; S, 12.45%.
1-(2-Hydroxyphenyl)-3-(2-chlorophenyl)propane-1,3-dione (6f).
Yield 78%, mp = 92 1C (EtOH). 1H NMR (CDCl3),
d 14.8 (s, 1HOH), 12.02 (s, 1HOH), 7.66–7.74 (m, 2HAr),
7.34–7.52 (m, 4HAr), 6.88–7.04 (m, 2HAr), 6.80 (s, 1H). Anal.
Calc. for C15H11ClO3: C 65.59; H 4.04; Cl 12.91. Found: C
65.72; H 4.20; Cl 13.02%.
2-Acetylphenyl 2-chlorobenzoate (5f). Yield 88%, mp =
1
63–65 1C (EtOH). H NMR (CDCl3) d 8.19 (d, J = 6.9 Hz,
1HAr), 7.88 (d, J = 7.8 Hz, 1HAr), 7.30–7.65 (m, 6HAr), 2.58
(s, 3HMe). Anal. Calc. for C15H11ClO3: C 65.59; H 4.04; Cl
12.91. Found: C 65.45; H 3.93; Cl 12.99%.
1-(2-Hydroxyphenyl)-3-(2-bromphenyl)propane-1,3-dione (6g).
Yield 86%, mp = 85–88 1C (EtOH). 1H NMR (CDCl3) d
15.19 (s, 1HOH), 12.04 (s, 1HOH), 7.30–7.73 (m, 6HAr),
6.88–7.04 (m, 2HAr), 6.72 (s, 1H). Anal. Calc. for,
C15H11BrO3: C 56.45; H 3.47; Br 25.04. Found: C 56.38; H
3.56; Br 24.95%.
2-Acetylphenyl 2-brombenzoate (5g). Yield 70%, mp =
1
72–74 1C (EtOH). H NMR (CDCl3) d 8.18 (d, J = 7.3 Hz,
1HAr), 7.88 (d, J = 7.7 Hz, 1HAr), 7.75 (d, J = 7.6 Hz, 1HAr),
7.62 (t, J = 7.7 Hz, 1HAr), 7.25–7.35 (m, 4HAr), 2.59
(s, 3HMe). Anal. Calc. for C15H11BrO3: C 56.45; H 3.47; Br
25.04. Found: C 56.38; H 3.58; Br 24.90%.
General procedure for the preparation of propane-1,3-dione
derivatives (6)
General procedure for the preparation of 3-acyl-2-alkyl-4H-
chromen-4-ones (7)
A solution of o-acyloxyacetophenone (5) (0.0125 mol) in DMF
(20 ml) was added to a solution of t-BuOK (2.8 g, 0.025 mol)
under argon at 0 1C during 10 min. The mixture was kept for
1 h and then poured into an ice-cooled 3% hydrochloric acid
AcONa/C2H5COONa (6.5 mmol) was added to diketone
(6.5 mmol) in 10 ml of acetic anhydride/propionic anhydride.
The reaction solution was refluxed for 30–60 min (TLC
monitoring). After completion of the reaction, the solution
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was poured into water. The solid compound was filtered off
and recrystallized from EtOH.
125.5, 123.6, 122.5, 118.0, 26.4, 11.8. Anal. Calc. for
C18H14O3: C 77.68; H 5.07. Found: C 77.55; H 5.15%.
General procedure for the preparation of 3-acyl-2,2-
3-Benzoyl-2-methyl-4H-chromen-4-one (7a). Yield 90%,
1
mp = 115–117 1C (EtOH) (lit. 117 1C19). H NMR (CDCl3),
dibromomethyl-4H-chromen-4-one (8)
d 8.20 (d, J = 7.8 Hz, 1HAr), 7.92 (d, J = 6.9, 2HAr), 7.70
(t, J = 7.6 Hz, 1HAr), 7.60 (d, J = 7.3 Hz, 1HAr), 7.40–7.51
(m, 4HAr), 2.4 (s, 3HMe). Anal. Calc. for C17H12O3: C 77.26;
H 4.58. Found: C 77.12; H 4.50%.
A solution of bromine (7.5 mmol) in 5 ml of CCl4 was added
portionwise to methylchromone 7 (3.4 mmol) in 20 ml of hot
CCl4. The solution was refluxed for 1.5–2 h (TLC monitoring).
After completion of the reaction, the solution was concen-
trated. The solid compound was washed or recrystallized
from EtOH.
3-(4-Chlorobenzoyl)-2-methyl-4H-chromen-4-one (7b). Yield
79%, mp = 126 1C (EtOH). 1H NMR (CDCl3), d 8.18 (d,
J = 7.8 Hz, 1H), 8.85 (d, J = 8.4 Hz, 2H), 7.72 (t, J = 7.8 Hz,
1H), 7.40–7.52 (m, 4H), 2.41 (s, 3H). Anal. Calc. for
C17H11ClO3: C 68.35; H 3.71; Cl 11.87. Found: C 68.27; H
3.60; Cl 11.83%.
2,2-Dibromomethyl-3-benzoyl-4H-chromen-4-one (8a). Yield
85%, mp = 157 1C (EtOH). 1H NMR (CDCl3), d 8.20 (d,
J = 9.2 Hz, 1HAr), 7.79–7.92 (m, 3HAr); 7.61–7.73 (m, 2HAr),
7.47–7.53 (m, 3HAr), 6.5 (s, 1HCH). MS (EI 70 eV) m/z
(relative intensity): 424(2), 422(3), 420(2), 346(1), 345(3),
343(76), 342(75), 241(11), 314(1), 277(3), 267(3), 265(16),
264(16), 263(100), 262(23), 250(4), 249(32), 236(22), 235(67),
234(35), 233(59). Anal. Calc. for C17H10Br2O3: C 48.38; H
2.39; Br 37.86. Found: C 48.23; H 2.43; Br 37.80%.
3-(Furancarbonyl)-2-methyl-4H-chromen-4-one (7c)
1
Yield 78.5%, mp = 146–148 1C (EtOH). H NMR (CDCl3),
d 8.18 (d, J = 7.9 Hz, 1HAr), 7.60–7.72 (m, 2HAr), 7.43
(t, J = 7.0 Hz, 2HAr), 7.20 (d, J = 3.5 Hz, 1HAr), 6.55 (t, J =
1.7 Hz, 1HAr), 2.40 (s, 3HMe). 13C NMR (CDCl3, 75 MHz),
d 180.6 (CQO), 175.5 (CQO), 166.0, 155.9, 153.0, 147.5,
134.1, 126.0, 125.6, 123.6, 122.6, 120.1, 117.9, 112.7, 19.0
(CH3). Anal. Calc. for C15H10O4: C 70.86; H 3.96. Found: C
70.80; H 4.03%.
2,2-Dibromomethyl-3-(4-chlorobenzoyl)-4H-chromen-4-one (8b).
Yield 89%, mp = 196–197 1C (EtOH). 1H NMR (CDCl3),
d 8.19 (d, J = 8.0 Hz, 1HAr), 7.69–7.88 (m, 4HAr), 7.43–7.55
(m, 3HAr), 6.5 (s, 1HCH). MS (EI 70 eV) m/z (relative
intensity): 457(5), 456(11), 455(7), 380(1), 379(31), 377(77),
376(67), 342(14), 340(31), 298(31), 297(7), 296(100),
283(26), 271(24), 270(41), 269(57), 262(66). Anal. Calc. for
C17H9Br2ClO3: C 44.73; H 1.99; Br 35.01; Cl 7.77. Found: C
44.61; H 2.10; Br 34.97; Cl 7.65%.
2-Methyl-3-(thiophene-2-carbonyl)-4H-chromen-4-one (7d).
1
Yield 75%, mp = 116–118 1C (EtOH). H NMR (CDCl3), d
8.20 (d, J = 7.9 Hz, 1HAr), 7.71 (t, J = 6.5 Hz, 2HAr).7.62
(d, J = 3.2 Hz, 1HAr), 7.39–7.50 (m, 2HAr), 7.12 (t, J =
4.2 Hz, 1HAr), 2.42 (s, 3HMe). Anal. Calc. for C15H10O3S: C
66.65; H 3.73; S 11.86. Found: C 66.58; H 3.84; S 11.75%.
2,2-Dibromomethyl-3-(thiophene-2-carbonyl)-4H-chromen-4-
one (8d). Yield 55%, mp = 153–155 1C (EtOH). 1H NMR
(CDCl3), d 8.22 (d, J = 7.8, 1HAr), 7.47–7.87 (m, 5HAr), 7.16
(d, J = 3.7 Hz, 1HAr), 6.5 (s, 1HCH). MS (EI 70 eV) m/z
(relative intensity): 430(12), 428(16), 427(5), 426(10), 350(4),
349(26), 348(43), 347(30), 349(41), 302(5), 280(6), 270(15),
269(100), 268(96), 266(17). Anal. Calc. for C15H8Br2O3S: C
42.09; H 1.88; Br 37.33; S 7.49. Found: C 41.98; H 2.00; Br
37.07; S 7.44%.
2,6-Dimethyl-3-(thiophene-2-carbonyl)-4H-chromen-4-one
(7e). Yield 60%, mp = 123–125 1C (EtOH). 1H NMR
(CDCl3), d 8.0 (s, 1HAr), 7.71 (d, J = 4.9 Hz, 1HAr), 7.62
(d, J = 3.8 Hz, 1HAr), 7.50 (d, J = 9.5, 1HAr), 7.37 (d, J =
8.6 Hz, 1HAr), 7.11 (t, J = 4.3 Hz, 1HAr), 2.47 (s, 3HMe), 2.40
(s, 3HMe). Anal. Calc. for C16H12O3S: C 67.59; H 4.25; S
11.28. Found: C 67.48; H 4.40; S 11.15%.
3-(2-Chlorobenzoyl)-2-methyl-4H-chromen-4-one (7f). Yield
94%, mp = 157–159 1C (EtOH). 1H NMR (CDCl3), d 8.12 (d,
J = 7.9 Hz, 1HAr), 7.66–7.73 (m, 2HAr), 7.40–7.49 (m, 5HAr),
2.61 (s, 3HMe). Anal. Calc. for C17H11ClO3: C 68.35; H 3.71;
Cl 11.87. Found: C 68.28; H 3.82; Cl 11.94%.
General procedure for the preparation of 3-acyl-2-bromoalkyl-
4H-chromen-4-one (9)
Bromine (0.84 mmol) was added portionwise to alkyl-
chromone 7 (0.76 mmol) in 5 ml of hot CCl4. The solution
was stirred for 30 min at 60–70 1C (TLC monitoring). After
completion of the reaction, the solution was concentrated. The
solid compound was washed with or recrystallized from
EtOH. The resulting ethanol solution contains a small amount
of dibromide 8 that can be isolated by column chromatography.
3-(2-Brombenzoyl)-2-methyl-4H-chromen-4-one (7g). Yield
1
80%, mp = 156–158 1C (EtOH). H NMR (CDCl3), d 8.12
(d, J = 7.9 Hz, 1HAr), 7.58–7.73 (m, 3HAr), 7.33–7.49
(m, 4HAr), 2.63 (s, 3HMe). Anal. Calc. for C17H11BrO3: C
59.50; H 3.23; Br 23.28. Found: C 59.38; H 3.41; Br 23.20%.
2-Bromomethyl-3-benzoyl-4H-chromen-4-one (9a). Yield
1
80%, mp = 152–153 1C (EtOH). H NMR (CDCl3), d 8.18
3-Benzoyl-2-ethyl-4H-chromen-4-one (7h). Yield 60%,
1
mp = 63–65 1C (EtOH) (lit. 64–65 1C24). H NMR (CDCl3),
(d, J = 7.7 Hz, 1HAr), 7.91 (d, J = 7.62 Hz, 2HAr), 7.77 (t,
J = 7.7 Hz, 1HAr), 7.46–7.68 (m, 5HAr), 4.34 (s, 2HCH). 13C
NMR (CDCl3, 75 MHz), d 193.2 (CQO), 176.3 (CQO), 162.1,
156.0, 137.3, 135.1, 134.0, 129.8, 129.2, 126.5, 126.4, 123.9,
118.6, 25.2. MS (EI 70 eV) m/z (relative intensity): 343(2),
315(6), 313(4), 297(1), 278(2), 265(12), 264(43), 263(100),
d 8.19 (dd, J = 8.0, 1.5 Hz, 1HAr), 7.94 (d, J = 8.5 Hz, 2HAr),
7.72 (t, J = 8.6 Hz, 1HAr), 7.60 (t, J = 7.3 Hz, 1HAr),
7.41–7.53 (m, 4HAr), 2.65 (q, J = 7.5 Hz, 2HCH), 1.32
(t, J = 7.5 Hz, 3HMe). 13C NMR (CDCl3, 75 MHz), d 193.9,
176.2, 169.3, 156.2, 137.3, 134.1, 133.9, 129.5, 128.8, 126.1,
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262(4). Anal. Calc. for C17H11BrO3: C 59.50; H 3.23; Br 23.28.
Found: C 59.62; H 3.35; Br 23.20%.
279(6), 278(14), 277(100), 276(53), 275(44), 263(13), 262(13),
250(6), 249(57), 248(4), 247(35), 235(2), 234(13). Anal. Calc.
for C18H13BrO3: C 60.53; H 3.67; Br 22.37. Found: C 60.43; H
3.56; Br 22.48%.
2-Bromomethyl-3-(4-chlorobenzoyl)-4H-chromen-4-one (9b).
1
Yield 94%, mp = 177–179 1C (EtOH). H NMR (CDCl3), d
Procedure for the preparation of 5-bromo-1-phenyl-9H-
thieno[3,4-b]chromen-9-one (10)
8.19 (d, J = 8.1 Hz, 1HAr), 7.75–7.89 (m, 3HAr), 7.60–7.44 (m,
4H), 4.36 (s, 2HCH). MS (EI 70 eV) m/z (relative intensity):
380(13), 378(17), 377(5), 376(9), 342(3), 300(9), 299(40),
298(22), 297(100), 284(3), 283(6), 272(2), 271(32), 269(52),
267(6), 262(27). Anal. Calc. for C17H10BrClO3: C 54.07; H
2.67; Br 21.16; Cl 9.39. Found: C 54.13; H 2.55; Br 21.07;
Cl 9.33%.
Thienochromone 11 (1 mmol) was dissolved in 5 ml of
dichloromethane. Then Br2 (1.1 mmol) was added portion-
wise. The solution was stirred at room temperature for 1 h
(TLC monitoring). The solvent was evaporated, and the
residue was washed with hot ethanol.
1
Yield 87%, mp = 184–186 1C (EtOH). H NMR (CDCl3),
2-Bromomethyl-(3-furan-2-carbonyl)-4H-chromen-4-one
(9c). Yield 65%, mp = 182–183 1C (EtOH). 1H NMR
(CDCl3), d 8.22 (d, J = 8.0 Hz, 1HAr), 7.76 (t, J = 7.7 Hz,
1HAr), 7.67 (s, 1HAr), 7.55 (d, J = 8.5 Hz, 1HAr), 7.47 (t, J =
d 8.22 (d, J = 7.9 Hz, 1HAr), 7.67–7.74 (m, 3HAr), 7.46–7.49
(m, 4HAr), 7.32–7.36 (m, 1HAr). MS (EI 70 eV) m/z (relative
intensity): 359(21), 358(98), 357(21), 356(100), 355(39), 279(9),
278(33), 277(19), 276(32), 249(5), 248(3), 221(4), 220(7),
219(3), 189(3), 179(5), 176(31), 158(6), 157(57). Anal. Calc.
for C17H9BrO2S: C 57.16; H 2.54; Br 22.37; S 8.98. Found: C
57.04; H 2.39; Br 22.24; S 8.93%.
7.6 Hz, 1HAr), 7.29 (s, 1HAr), 6.6 (s, 1HAr), 4.37 (s, 2HCH). 13
C
NMR (CDCl3, 75 MHz), d 179.1 (CQO), 175.6 (CQO), 162.2,
155.9, 152.7, 148.0, 134.8, 126.2, 126.1, 123.66, 120.93, 118.23,
112.92. MS (EI 70 eV) m/z (relative intensity): 334(2), 332(2),
280(1), 265(2), 255(3), 254(16), 253(100), 252(59), 237(2),
236(5), 228(2), 227(15), 226(94), 225(34), 224(20), 223(6).
Anal. Calc. for C15H9BrO4: C 54.08; H 2.72; Br 23.99. Found:
C 53.97; H 2.60; Br 23.87%.
General procedure for the preparation of 1-aryl-9H-thieno[3,4-b]-
chromen-9-ones (11)
Thioacetamide (144 mg, 1.92 mmol) or (211 mg, 2.81 mmol)
was added to 1.3 mmol of monobromo (9) or dibromomethyl-
chromone (8), respectively in 5 ml of DMF. The reaction
mixture was heated at 70–80 1C for 40–60 min (TLC monitor-
ing) in the case of 9 and 80–100 1C for 60–90 min in the case of
8 (TLC monitoring), cooled to room temperature, and diluted
with water. The solid product was filtered off, dried, dissolved
in CH2Cl2/petroleum ether (1:1), and filtered through silica
gel. After evaporation of the solvent, the sample was dried in
air. The analytical sample was obtained by recrystallization of
the compound from boiling ethanol.
2-Bromomethyl-3-(thiophene-2-carbonyl)-4H-chromen-4-one
(9d). Yield 69%, mp = 158–160 1C (EtOH). 1H NMR
(CDCl3), d 8.21 (d, J = 7.8 Hz, 1HAr), 7.87–7.54 (m, 5HAr),
7.13-7.14 (m, 1HAr), 4.34 (s, 2HCH). MS (EI 70 eV) m/z
(relative intensity): 351(2), 350(15), 349(4), 348(15), 347(4),
270(26), 269(80), 242(13), 241(46), 240(33), 239(36), 225(17),
213(9), 209(26), 187(21), 184(38), 175(7), 163(7), 151(13),
148(17), 139(46), 135, 121(100). Anal. Calc. for C15H9BrO3S:
C 51.59; H 2.60; Br 22.88; S 9.18. Found: C 51.48; H 2.52; Br
23.03; S 9.24%.
1-Phenyl-9H-thieno[3,4-b]chromen-9-one (11a). Yield 86%
(from 9), 74% (from 8), mp = 159–160 1C (EtOH). 1H
NMR (CDCl3), d 8.25 (d, J = 7.9 Hz, 1HAr), 7.65–7.77 (m,
3HAr), 7.29–7.48 (m, 5HAr), 7.02 (s, 1HAr). MS (EI 70 eV) m/z
(relative intensity): 280(5), 279(19), 278(82), 277(100), 261(2),
249(1), 248(2), 233(2), 221(6), 220(2), 205(3), 195(1), 189(6),
176(8), 171(4). 13C NMR (CDCl3, 75 MHz), d 175.1 (CQO),
156.7, 153.4, 149.3, 135.3, 133.4, 130.3, 129.6, 128.5, 127.7,
123.7, 121.9, 121.5, 117.7, 102.9. Anal. Calc. for C17H10O2S: C
73.36; H 3.62; S 11.52. Found: C 73.43; H 3.67; S 11.43%.
2-Bromomethyl-3-(2-chlorobenzoyl)-4H-chromen-4-one (9f).
Yield 94%, mp = 128–130 1C (EtOH). 1H NMR (CDCl3),
d 8.05 (d, J = 7.9 Hz, 1HAr), 7.60–7.70 (m, 2HAr), 7.47 (d, J =
8.4 Hz, 1HAr), 7.30–7.40 (m, 4HAr), 4.52 (s, 2HCH). MS
(EI 70 eV) m/z (relative intensity): 378(1), 376(1), 343(8),
341(8), 296(3), 265(4), 264(41), 263(100), 262(34), 261(7).
Anal. Calc. for C17H10BrClO3: C 54.07; H 2.67; Br 21.16;
Cl 9.39. Found: C 54.18; H 2.80; Br 21.03; Cl 9.23%.
2-Bromomethyl-3-(2-brombenzoyl)-4H-chromen-4-one (9g).
1
Yield 82%, mp = 155–156 1C (EtOH). H NMR (CDCl3), d
1-(4-Chlorophenyl)-9H-thieno[3,4-b]chromen-9-one
(11b).
8.12 (d, J = 7.7 Hz, 1HAr), 7.78–7.43 (m, 7HAr), 4.61
(s, 2HCH), MS (EI 70 eV) m/z (relative intensity): 344(2),
342(2), 265(5), 264(58), 263(100), 262(51), 249(23), 236(27),
235(52), 234(12), 205(6), 191(2), 189(6), 187(34). Anal. Calc.
for C17H10Br2O3: C 48.38; H 2.39; Br 37.86. Found: C 48.29 H
2.45 Br 37.80%.
Yield 75% (from 9), 70% (from 8), mp = 205 1C (EtOH).
1H NMR (CDCl3), d 8.25 (d, J = 7.8 Hz, 1HAr), 7.70 (d, J =
8.1 Hz, 3HAr), 7.31–7.47 (m, 4HAr), 7.07 (s, 1HAr). MS (EI
70 eV) m/z (relative intensity): 315(2), 314(42), 313(36),
312(100), 311(58), 306(2), 302(1), 300(3), 295(1), 280(1),
279(4). Anal. Calc. for C17H9ClO2S: C 65.28; H 2.90; Cl
11.33; S 10.25. Found: C 65.15; H 3.01; Cl 11.22; S 10.19%.
3-Benzoyl-2-(1-bromoethyl)-4H-chromen-4-one (9h). Yield
1
75%, mp = 105–106 1C (EtOH). H NMR (CDCl3), d 8.19
(d, J = 7.9 Hz, 1HAr), 7.93 (d, J = 7.6 Hz, 2HAr), 7.78 (t, J =
7.8 Hz, 1HAr), 7.60–7.67 (m, 2HAr). 7.45–7.55 (m, 3HAr), 5.00
(q, J = 13.6, 6.8 Hz, 1HCH), 2.05 (d, J = 6.8 Hz, 3HMe). MS
(EI 70 eV) m/z (relative intensity): 358(4), 356(4), 284(2),
1-Furyl-9H-thieno[3,4-b]chromen-9-one (11c). Yield 75%
(from 9), mp = 138–140 1C (EtOH). 1H NMR (CDCl3), d
8.30 (d, J = 7.9 Hz, 1HAr), 8.13 (d, J = 3.5 Hz, 1HAr), 7.67
(t, J = 7.7 Hz, 1HAr), 7.51 (s, 1HAr), 7.29–7.36 (m, 2HAr), 6.91
(s, 1HAr), 6.60 (dd, J = 3.1, 1.4 Hz, 1HAr). 13C NMR (CDCl3,
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75 MHz), d 174.7, 156.1, 153.0, 148.5, 143.4, 134.9, 127.3,
123.5, 121.6, 117.3, 113.86, 113.0, 100.8. MS (EI 70 eV) m/z
(relative intensity): 270 (38), 269(41), 268(100), 267(30), 251(2),
242(6), 241(24), 240(57), 239(59), 214(8), 213(7), 212(65),
211(96). Anal. Calc. for C15H8O3S, C 67.15; H 3.01; S 11.95.
Found: C 67.23; H 3.10; S 11.82%.
234(38). Anal. Calc. for C19H14O5: C 70.80; H 4.38. Found:
C 70.71; H 4.33%.
Procedure for the preparation of 3-iodo-1-phenyl-9H-thieno[3,4-b]-
chromen-9-one (13)
Thienochromone 11a (278 mg, 1 mmol) was dissolved in 3 ml
of benzene. Then HgO (217 mg, 1 mmol) and I2 (258 mg,
1 mmol) were successively added portionwise. The solution
was stirred at room temperature for 1 h (TLC monitoring).
The solvent was evaporated. The residue was washed with hot
ethanol.
Yield 82%, mp = 176–178 1C (EtOH). 1H NMR (CDCl3), d
8.22 (dd, J = 7.9, 1.6 Hz, 1HAr), 7.66–7.75 (m, 3HAr),
7.44–7.51 (m, 4HAr), 7.26–7.38 (m, 1HAr). MS (EI 70 eV) m/
z (relative intensity): 405(21), 404(100), 402(4), 280(1), 279(4),
278(17), 277(30), 276(15), 254(1), 234(5), 233(16), 232(2),
221(10), 220(2), 219(6). Anal. Calc. for C17H9IO2S: C 50.51;
H 2.24; I 31.39; S 7.93. Found: C 50.63; H 2.32; I 31.47;
S 7.79%.
1-Thienyl-9H-thieno[3,4-b]chromen-9-one (11d). Yield 85%
(from 9), 55% (from 8), mp = 137–138 1C (EtOH). 1H NMR
(CDCl3), d 8.29 (d, J = 7.9 Hz, 1HAr), 7.87 (d, J = 3.5 Hz,
1HAr), 7.87 (t, J = 7.6 Hz, 1HAr), 7.47 (d, J = 5.1 Hz, 1HAr),
7.24–7.37 (m, 2HAr), 7.14 (t, J = 4.4 Hz, 1HAr), 6.92 (s, 1HAr).
13C NMR (CDCl3, 75 MHz), d 174.9, 156.2, 152.9, 141.9,
135.0, 134.7, 129.8, 128.7, 127.7, 127.4, 123.5, 121.5, 120.7,
117.3, 101.3. MS (EI 70 eV) m/z (relative intensity): 287(2),
286(15), 285(6), 284(100), 283(33). Anal. Calc. for C15H8O2S2:
C 63.36; H 2.84; S 22.55. Found: C 63.46; H 2.99; S 22.45%.
1-(2-Chlorophenyl)-9H-thieno[3,4-b]chromen-9-one
(11f).
Yield 75% (from 9), mp = 155–156 1C (EtOH). 1H NMR
(CDCl3), d 8.20 (d, J = 7.8 Hz, 1HAr), 7.68 (t, J = 7.4 Hz,
1HAr), 7.29–7.64 (m, 6H), 7.13 (s, 1H). 13C NMR (CDCl3,
75 MHz), d 174.5, 156.7, 152.3, 143.4, 135.1, 134.8, 132.3,
132.1, 130.5, 129.7, 127.3, 126.5, 123.8, 123.5, 121.5, 117.6. MS
(EI 70 eV) m/z (relative intensity): 312(2), 311(1), 280(2),
279(14), 278(20), 277(100), 276(4), 269(1), 264(3), 263(26).
Anal. Calc. for C17H9ClO2S: C 65.28; H 2.90; Cl 11.33; S
10.25. Found: C 65.15; H 3.01; Cl 11.40; S 10.15%.
General procedure for the preparation of 1-aryl-9H-thieno[3,4-b]-
chromen-9-one-3-carbaldehyde (14)
MeOCHCl2 (0.11 ml, 1.2 mmol) was added with stirring and
ice/brine cooling to compounds 11a,c,d,f (1 mmol) and SnCl4
(390 mg, 1.5 mmol) in dry 1,2-dichloroethane (10 ml). After
completion of the reaction (TLC monitoring), the solution was
poured into water. The organic layer was separated, washed
with water, dried, and filtered through silica gel with CH2Cl2
as the solvent. Evaporation of the solvent and washing with
cold EtOH gave 14a,c,d,f.
3-Methyl-1-phenyl-9H-thieno[3,4-b]chromen-9-one
(11h).
Yield 55% (from 9), mp = 142–143 1C (EtOH). 1H NMR
(CDCl3), d 8.25 (d, J = 7.8 Hz, 1HAr), 7.64–7.75 (m, 3HAr),
7.39–7.46 (m, 4HAr), 7.25–7.30 (m, 1HAr), 2.61 (s, 3HMe). MS
(EI 70 eV) m/z (relative intensity): 294(8), 293(30), 292(87),
291(100), 277(2). Anal. Calc. for C18H12O2S: C 73.95; H 4.14;
S 10.97. Found: C 73.81; H 4.02; S 11.04%.
9-Oxo-1-phenyl-9H-thieno[3,4-b]chromene-3-carbaldehyde
(14a). Yield 83%, mp = 186–187 1C (EtOH). 1H NMR
(CDCl3), d 10.39 (s, 1HCH), 8.28 (d, J = 7.8 Hz, 1HAr),
7.74–7.81 (m, 3HAr), 7.38–7.55 (m, 5HAr). MS (EI 70 eV) m/
z (relative intensity): 308(9), 307(13), 306(100), 305(95), 304(2),
294(1), 283(2), 278(4), 277(39), 276(2), 261(2), 251(2), 249(6),
245(2), 235(1), 234(4), 233(20). Anal. Calc. for C18H10O3S: C
70.57; H 3.29; S 10.47. Found: C 70.68; H 3.36; S 10.34%.
Procedure for the preparation of (3-aryl-4-oxo-4H-chromen-2-yl)-
methyl acetate (12)
A solution of bromochromone 9a (343 mg, 1 mmol) in 6 ml of
DMF was added to AcONa (106.6 mg, 1.3 mmol). After
stirring at 0 1C for 4 h, the temperature of the solution was
raised to 30–40 1C. After completion of the reaction (TLC
monitoring), the solution was poured into cold water and
extracted three times with CH2Cl2 or AcOEt. The combined
extracts were washed with brine and dried with Na2SO4.
Petroleum ether (1 volume in the case of the CH2Cl2 solvent
and 3 volumes in the case the AcOEt solvent) was added to the
reaction solution. After filtration through silica gel and eva-
poration of the solvent, the solid compound was washed with
cold ethanol, and a white acylated product was obtained.
1-Furan-2-yl-9-oxo-9H-thieno[3,4-b]chromene-3-carbaldehyde-
one (14c). Yield 35% mp = 195–197 1C (EtOH). 1H NMR
(CDCl3), d 10.34 (s, 1HCH), 8.47 (d, J = 3.7 Hz, 1HAr), 8.33
(d, J = 7.9 Hz, 1HAr), 7.76 (t, J = 7.1 Hz, 1HAr), 7.63 (s, 1HAr),
7.40–7.50 (m, 2HAr), 6.68 (dd, J = 3.5, 1.5 Hz, 1HAr).
MS (EI 70 eV) m/z (relative intensity): 298(7), 296(76),
295(100), 294(36), 268(10), 267(8), 239(11), 238(25), 211(8),
210(36). Anal. Calc. for C16H8O4S: C 64.86; H 2.72; S 10.82.
Found: C 64.93; H 2.84; S 10.75%.
9-Oxo-1-thiophen-2-yl-9H-thieno[3,4-b]chromene-3-carbalde-
1
hyde (14d). Yield 48% mp = 189–191 1C (EtOH). H NMR
(3-Benzoyl-4-oxo-4H-chromen-2-yl)methyl acetate (12)
(CDCl3), d 10.31 (s, 1HCH), 8.30 (d, J = 7.4 Hz, 1HAr), 8.13
(d, J = 3.7 Hz, 1HAr), 7.75 (t, J = 7.8 Hz, 1HAr), 7.63 (d, J =
5.0 Hz, 1HAr) 7.31–7.49 (m, 2HAr), 7.19 (t, J = 4.9 Hz, 1HAr).
MS (EI 70 eV) m/z (relative intensity): 314(15), 313(11),
312(100), 311(28), 310(8), 284(21), 238(21), 255(3), 240(3),
239(24). Anal. Calc. for C16H8O3S2: C 61.52; H 2.58; S
20.53. Found: C 61.57; H 2.50; S 20.47%.
1
Yield 65%, mp = 168 1C (EtOH). H NMR (CDCl3), d 8.21
(d, J = 7.9 Hz, 1HAr), 7.92 (d, J = 7.5 Hz, 2HAr), 7.75 (t, J =
7.4 Hz, 1HAr), 7.44–7.63 (m, 5HAr), 5.07 (s, 2HCH), 1.85 (s,
3HMe). MS (EI 70 eV) m/z (relative intensity): 324(3), 322(11),
321(2), 293(9), 281(2), 280(31), 279(50), 264(6), 263(31),
262(100), 252(5), 251(7), 250(6), 249(18), 236(2), 235(13),
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1-(2-Chlorophenyl)-9-oxo-9H-thieno[3,4-b]chromene-3-carb-
aldehyde (14f). Yield 55%, mp = 172–174 1C (EtOH). 1H
NMR (CDCl3), d 10.41 (s, 1HCH), 8.23 (d, J = 7.5 Hz, 1HAr),
7.77 (t, J = 7.7 Hz, 1HAr), 7.36–7.60 (m, 6HAr). MS (EI 70 eV)
m/z (relative intensity): 340(2), 308(6), 307(16), 306(73),
305(100), 279(3), 278(15), 277(82). Anal. Calc. for
C18H9ClO3S: C 63.44; H 2.66; Cl 10.40; S 9.41. Found: C
63.56; H 2.74; Cl 10.48; S 9.30%.
d 181.3 (CQO), 174.2 (CQO), 155.8, 153.8, 151.1, 145.6,
135.5, 133.9, 132.2, 131.7, 131.6, 131.2, 130.2, 130.0, 129.9,
128.5, 128.4, 128.2, 127.4, 124.3, 121.7, 119.7, 117.9, 117.7.
MS (EI 70 eV) m/z (relative intensity): 439(13), 438(99),
409(1), 381(2), 354(1), 332(3), 305(1), 304(15), 303(100),
288(1), 279(1), 278(6), 277(5), 276(1). Anal. Calc. for
C27H18O4S: C 73.96; H 4.14; S 7.31. Found: C 74.03; H 4.28;
S 7.23%.
General procedure for the preparation of azomethines (15)
3-[-3-Oxo-3-(2-thienyl)prop-1-en-1-yl]-1-phenyl-9H-thieno-
[3,4-b]chromen-9-one (16c). Yield 74%, mp = 208–212 1C
(EtOH). H NMR (CDCl3), d 8.31 (d, J = 15.3 Hz, 1HCH),
8.25 (d, J = 6.5 Hz, 1HAr), 7.70–7.90 (m, 5HAr), 7.40–7.52 (m,
4HAr), 7.20–7.36 (m, 3HAr+CH). MS (EI 70 eV) m/z (relative
intensity): 441(1), 440(2), 439(7), 438(32), 411(1), 410(3),
409(7), 333(4), 332(4), 331(8), 306(3), 305(15), 304(23),
303(100), 280(2), 279(4), 278(27), 277(13). Anal. Calc. for
C24H14O3S2: C 69.54; H 3.40; S 15.47. Found: C 69.43; H
3.51; S 15.54%.
Amine (1 mmol) was added to aryl-5-carbonyl-9H-thieno[3,4-b]-
chromen-9-one 14a (306 mg, 1 mmol) in 5 ml of ethanol. The
solution was refluxed and then cooled. The solid compound
was filtered off and recrystallized from ethanol.
1
1-Phenyl-3-((phenylimino)methyl)-9H-thieno[3,4-b]chromen-
9-one (15a). Yield 80%, mp = 185–186 1C (EtOH). 1H NMR
(CDCl3), d 8.99 (s, 1HCH); 8.27 (d, J = 7.6 Hz, 1HAr),
7.70–7.82 (m, 3HAr), 7.30–7.51 (m, 10HAr). MS (EI 70 eV)
m/z (relative intensity): 383(1), 382(29), 381(100), 380(6),
307(6), 306(14), 305(24), 279(1), 278(3), 277(10), 265(1),
264(5), 323(24). Anal. Calc. for C24H15NO2S,%: C 75.57; H
3.96; N 3.67; S 8.41. Found: C 75.45; H 4.04; N 3.77; S 8.30%.
General procedure for the preparation of 3,30-(2-aryl-2-oxoethane-
1,1-diyl)-bis(1-phenyl-9H-thieno[3,4-b]chromen-9-one) (19)
Tin(IV) tetrachloride (260 mg, 1 mmol) was added to a mixture
of 11 (1 mmol) and ketoaldehyde (17) (0.5 mmol) in dry
CH2Cl2 (5 ml) at room temperature. The solution was stirred
for 1 h and poured into water. The organic layer was dried
with Na2SO4, filtered through silica gel, and concentrated. The
residue was washed with ethanol and petroleum ether.
3-{[(4-Fluorophenyl)imino]methyl}-1-phenyl-9H-thieno[3,4-b]-
chromen-9-one (15b). Yield 92%, mp = 220–222 1C (EtOH).
1H NMR (2003 MHz, CDCl3), d 8.96 (s, 1HCH), 8.27 (d, J =
7.5, 1HAr), 7.82–7.68 (m, 3HAr), 7.40–7.21 (m, 7HAr), 7.16–7.08
(m, 2HAr). MS (EI 70 eV) m/z (relative intensity): 400(14),
399(100), 398(11), 397(2), 306(6), 305(2), 301(4), 292(1), 285(5),
284(9), 283(23). Anal. Calc. for C24H14FNO2S: C 72.17; H
3.53; F 4.76; N 3.51; S 8.03. Found: C 72.03; H 3.65; F 4.66; N
3.61; S 8.00%.
3,30-(2-Phenyl-2-oxoethane-1,1-diyl)-bis(1-phenyl-9H-thieno-
[3,4-b]chromen-9-one) (19a). Yield 75%, mp = 242 1C
(EtOH). 1H NMR (CDCl3), d 8.33 (d, J = 7.2 Hz, 2HAr),
8.25 (d, J = 7.9 Hz, 2HAr), 7.32–7.74 (m, 20HAr+CH). Anal.
Calc. for C42H24O5S2: C 74.98; H 3.60; S 9.53. Found: C 74.84;
H 3.75; S 9.42%.
General procedure for the preparation of 3-[3-oxo-3-(aryl)prop-
1-en-1-yl]-1-phenyl-9H-thieno[3,4-b]chromen-9-one (16)
A 40% aqueous KOH solution (0.14 ml) was added to
aldehyde 14 (1 mmol) in 10 ml of ethanol and the correspond-
ing ketone (1 mmol) (in the case of acetone, an ice-cooled 1 : 1
mixture of ethanol and acetone (10 ml) was used as the
solvent). The reaction mixture was stirred for 1 h (TLC
monitoring) and diluted with water. The solid compound
was filtered off, washed with water, and recrystallized from
ethanol.
3,30-(2-(4-Methylphenyl)-2-oxoethane-1,1-diyl)-bis(1-phenyl-
9H-thieno[3,4-b]chromen-9-one) (19b). Yield 87%, mp =
218–220 1C (EtOH). 1H NMR (CDCl3), d 8.23 (d, J = 8.0
Hz, 4HAr), 7.66–7.70 (m, 6HAr), 7.31–7.48 (m, 13HAr+CH),
2.43 (3HMe). Anal. Calc. for: C 75.20; H 3.82; S 9.34. Found: C
75.30; H 3.72; S 9.43%.
3,30-(2-(3-Methoxyphenyl)-2-oxoethane-1,1-diyl)-bis(1-phenyl-
9H-thieno[3,4-b]chromen-9-one) (19c). Yield 78%, mp =
248–250 1C (EtOH). 1H NMR (CDCl3), d 8.25 (d, J =
7.9 Hz, 2HAr), 7.97 (d, J = 7.8 Hz, 1HAr), 7.67–7.81
(m, 6HAr), 7.18–7.51 (m, 14HAr+CH), 3.87 (s, 3HMe). Anal.
Calc. for C43H26O6S2: C 73.49; H 3.73; S 9.12. Found: C 73.49;
H 3.73; S 9.12%.
3-[3-Oxobut-1-en-1-yl]-1-phenyl-9H-thieno[3,4-b]chromen-9-
1
one (16a). Yield 60%, mp = 189–190 1C (EtOH). H NMR
(CDCl3), d 8.26 (d, J = 8.1 Hz, 1HAr), 8.01 (d, J = 15.9 Hz,
1HCH), 7.71–7.78 (m, 3HAr), 7.33–7.52 (m. 5HAr). 6.66 (d, J =
15.9 Hz, 1HCH), 2.44 (s, 3HMe). MS (EI 70 eV) m/z (relative
intensity): 348(3), 347(22), 346(36), 333(3), 332(5), 331(61),
306(11), 305(19), 304(18), 303(100), 291(6), 284(3), 281(7),
278(3), 277(8). Anal. Calc. for C21H14O3S: C 72.81; H 4.07;
S 9.26. Found: C 72.79; H 4.13; S 9.34%.
3,30-(2-(2.5-Dimethylthiophen-3-yl)-2-oxoethane-1,1-diyl)-bis-
(1-phenyl-9H-thieno[3,4-b]chromen-9-one) (19d). Yield 80%,
mp = 236–237 1C (EtOH). 1H NMR (CDCl3), d 8.26
(d, J = 7.9 Hz, 2HAr), 7.66–7.78 (m, 6HAr), 7.31–7.48 (m,
11HAr+CH), 7.10 (s, 1HAr), 2.80 (s, 3HMe), 2.45 (s, 3HMe).
Anal. Calc. for C42H26O5S3: C, 71.37; H, 3.71; S, 13.61. Found:
C 71.25; H 3.84; S, 13.54%.
3-[3-(3-Methoxyphenyl)-3-oxoprop-1-en-1-yl]-1-phenyl-9H-
thieno[3,4-b]chromen-9-one (16b). Yield 85%, mp = 201–202 1C
1
(EtOH). H NMR (CDCl3), d 8.31 (d, J = 15.5 Hz, 1HCH),
8.25 (d, J = 8.9 Hz, 1HAr), 7.31–7.82 (m, 12HAr+CH), 7.16 (d,
J = 8.1 Hz, 1HAr), 3.91 (s, 3HMe). 13C NMR (CDCl3, 75 MHz),
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Bis(1-(2-chlorophenyl)-3,30-(2-(3-methoxyphenyl)-2-oxoethane-
1,1-diyl)-9H-thieno[3,4-b]chromen-9-one) (19e). Yield 65%,
mp = 216–217 1C (EtOH). 1H NMR (CDCl3), d 8.20 (d,
J = 6.9 Hz, 2HAr), 7.99 (d, J = 7.6 Hz, 1HAr), 7.82
(s, 1HAr), 7.71 (t, J = 7.2 Hz, 1HAr), 7.20–7.54 (m,
16HAr+CH), 3.88 (s, 3HMe). Anal. Calc. for C43H24Cl2O6S2:
C 66.93; H 3.13; Cl 9.19; S 8.31. Found: C 66.81; H 3.03; Cl
9.04; S 8.40%.
GOF = 0.929 for all independent reflections (R1 = 0.0511
was calculated against F for 6580 observed reflections with
I 4 2s(I)). All calculations were performed using SHELXTL
PLUS 5.0.
References
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Procedure for the preparation of (20)
Sodium tetrahydroborate (42 mg, 1.1 mmol) was added to
thienochromone (11a) (278 mg, 1 mmol.) in THF. After
completion of the reaction, the solvent was evaporated and
the residue was recrystallized from ethanol.
Yield 79%, mp = 153 1C (EtOH). 1H NMR (CDCl3), d 7.85
(d, J = 7.6 Hz, 2HAr), 7.11–7.53 (m, 7HAr), 6.76 (s, 1HAr),
5.88 (d, J = 7.6 Hz, 1HCH), 2.13 (d, J = 7.5 Hz, 1HOH). 13C
NMR (CDCl3, 75 MHz), d 151.7, 149.4, 141.5, 133.9, 130.4,
130.0, 129.1, 128.6, 128.4, 123.4, 122.7, 117.0, 101.3, 62.3. MS
(EI 70 eV) m/z (relative intensity): 281(5), 280(38), 279(23),
278(13), 265(16), 264(30), 263(90), 262(4), 236(2), 235(6),
219(2), 218(5), 205(6), 204(100), 203(55), 202(53), 201(32),
193(7), 192(40), 191(13), 190(45), 189(21), 188(51). Anal. Calc.
for C17H12O2S: C 72.83; H 4.31; S 11.44. Found: C 72.91; H
4.41; S 11.32%.
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Crystallographic data. Crystals of 19a (C49.50H41.50O5S3,
ꢀ
Mr = 809.99) are triclinic, space group P1, at 100 K:
a = 12.116(2), b = 12.633(3), c = 14.074(3) A, a =
´
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F(000) = 853. Intensities of 14629 reflections were measured
with a Smart APEX II CCD diffractometer [l(Mo-Ka) =
0.71072 A, o-scans, 2y o 551] and 9103 independent reflec-
tions [Rint = 0.0284] were used in further refinement. The
structure was solved by direct method and refined by the
full-matrix least-squares technique against F2 in the anisotropic/
isotropic approximation. Hydrogen atoms were located from
the Fourier synthesis and refined in the isotropic approximation.
Analysis of the Fourier density synthesis revealed that 19a
crystallizes with a solvate molecule, which is the superposition
of n-alkanes (crystals were obtained from the petroleum ether).
Upon the refinement of the solvate molecule, its atoms C(7S),
C(8s), C(9s) and C(10s) disordered around the center of
symmetry were refined with occupancies equal to 0.5, 0.5,
0.25 and 0.25, respectively. Due to the complicated disordering
scheme the hydrogens for C(8S)–C(10S) atoms were not
added. The refinement converged to wR2 = 0.1531 and
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ꢀc
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