Triphenylphosphine as an effective catalyst for ketoximes addition to acylacetylenes: Regio- and stereospecific synthesis of (E)-(O)-2-(acyl) vinylketoximes

Article abstract of DOI:10.1016/j.tet.2010.07.057

Triphenylphosphine catalyzes the regio- and stereospecific addition of ketoximes to acylacetylenes, whereas classical conditions using acetylene (KOH/DMSO, 70 °C) are unsuitable for this purpose. The reaction proceeds under mild conditions (CH₂Cl₂, rt, 7 h) to afford (E)-(O)-2-(acyl)vinylketoximes (92-98% stereoselectivity) in a yield of up to 85%. The (E)-adducts obtained are energetically less favorable than the corresponding (Z)-isomers and are gradually enriched with (Z)-isomers, thus indicating the kinetic control of (E)-stereoselectivity of the reaction.

Full text of DOI:10.1016/j.tet.2010.07.057

Tetrahedron 66 (2010) 7527e7532
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Triphenylphosphine as an effective catalyst for ketoximes addition to
acylacetylenes: regio- and stereospecific synthesis of (E)-(O)-2-(acyl)
vinylketoximes
*
Boris A. Trofimov , Tatyana E. Glotova, Marina Yu. Dvorko, Igor’ A. Ushakov, Elena Yu. Schmidt,
Al’bina I. Mikhaleva
A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St., 664033 Irkutsk, Russian Federation
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 12 May 2010
Received in revised form 2 July 2010
Accepted 20 July 2010
Available online 24 July 2010
Triphenylphosphine catalyzes the regio- and stereospecific addition of ketoximes to acylacetylenes,
whereas classical conditions using acetylene (KOH/DMSO, 70 ꢀC) are unsuitable for this purpose. The
reaction proceeds under mild conditions (CH2Cl2, rt, 7 h) to afford (E)-(O)-2-(acyl)vinylketoximes (92e98%
stereoselectivity) in a yield of up to 85%. The (E)-adducts obtained are energetically less favorable than the
corresponding (Z)-isomers and are gradually enriched with (Z)-isomers, thus indicating the kinetic control
of (E)-stereoselectivity of the reaction.
Keywords:
Oximes
Ó 2010 Elsevier Ltd. All rights reserved.
Acylacetylenes
Triphenylphosphine
O-vinylation
Isomerization
1. Introduction
To the best of our knowledge, the literature lacks data on the
interaction of oximes with acylacetylenes. The addition of oximes
Oximes and their derivatives are known to be important sub-
strates in organic and medicinal chemistry. Compounds containing
the oxime pharmacophore motif exert diverse biological activities
(antiviral, fungicidal, cytotoxic, antispasmodic, anticonvulsive,
etc.).1 Depending on the substituents, reagents, and reaction con-
ditions, oximes can behave as N-, O-, and C-nucleophiles,1,3-dipoles
(in the NH-nitrone form), electrophiles (objects of nucleophilic at-
tack across the C]N bond), and selective ligands for transition
metal cations.2
O-Vinyloximes are the key intermediates in the synthesis of pyr-
roles from ketones (via ketoximes) and acetylenes.2e,3 Of special im-
portance is the preparation and study of properties of O-vinyloximes
bearing the carbonyl group at the double bond. The combination of
the ketovinyl fragment (the known phaprmacophore4) and oxime
moiety in a one molecule could lead to synergism of properties
of these two important chemical functions and extent substantially
theapplicationsofthesehighlyfunctionalizedcompounds. Oneofthe
approaches to the synthesis of such O-vinyloximes could be the
vinylation of oximes with available acylacetylenes (commercial or
easily prepared by the known protocols5).
to electrophilic (activated) acetylenes was reported only in a few
publications dealing with the reactions of oximes with ethers of
propiolic and acetylene dicarboxylic acids.6
2. Results and discussion
O-Vinyloximes are commonly prepared by the vinylation of
ketoximes with acetylene in the superbase systems MOH/DMSO
(M¼Na, K, Cs).7 These conditions (KOH/DMSO, 20e70 ꢀC, up to 6 h)
turned out to be invalid for the addition of ketoximes to acylace-
tylenes (the reaction was accompanied by the intense tar formation
and the anticipated adducts were not formed). This result is also in
agreement with the known data on instability of acylacetylenes in
strongly basic (superbasic) media.8 When conducted in benzene
(80 ꢀC, 24 h), methanol (reflux, 24 h), tetrahydrofuran (reflux, 40 h),
dichloromethane (rt, 4 days) as well as in the system MeOH/Et3N
(reflux, 24 h), the reaction furnished the addition products in only
negligible yields (8e10%, 1H NMR).
Our further systematic investigations have shown that in the
presence of triphenylphosphine (10 mol %) ketoximes 1e4 are
readily added to acylacetylenes 5e7 in dichloromethane at room
temperature (7 h) to deliver the expected (E)-(O)-2-(acyl)vinyl-
ketoximes 8ael in a yield of up to 85% (Table 1).
* Corresponding author. Tel.: þ7 3952 511431; fax: þ7 3952 419346; e-mail
address: boris_trofimov@irioch.irk.ru (B.A. Trofimov).
0040-4020/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2010.07.057

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B.A. Trofimov et al. / Tetrahedron 66 (2010) 7527e7532
Table 1
Synthesis of (E)-(O)-2-(acyl)vinylketoximes 3aela
O
R2
R1
R3
10 mol% Ph3P
R1
R2
R3
+
Ph
N
N
O
CH2Cl2, rt, 7 h
OH
Ph
O
1-4
8a-l
5-7
Entry
1
Oximes 1e4
Acylacetylenes 5e7
Product 8ael
Isolated yields,b
% (isomer)
O
Me
Ph
Ph
Ph
Ph
83
(E,E)
Ph
O
1
1
1
2
5
6
7
5
Ph
N
8a
8b
8c
8d
Ph
N
O
OH
Ph
O
Me
O
Me
83
(E,E)
O
2
3
4
Ph
N
N
Ph
N
N
OH
Ph
O
O
O
Me
O
Me
85
(E,E)
S
Ph
Ph
S
OH
N
Ph
O
Me
O
Ph
82
(E,E)
Me
OH
Ph
Ph
Ph
O
N
O
Me
O
83
(E,E)
Me
OH
O
5
6
2
2
6
7
8e
8f
Ph
O
S
N
N
O
Ph
O
Me
O
84
(E,E)
Me
OH
S
Ph
N
N
O
Ph
O
Me
O
Ph
Me
82
S
S
S
Ph
Ph
7
8
9
3
3
3
5
6
7
S
8g
8h
8i
Ph
(E,E/E,Zz2:1)c
N
N
O
O
OH
Me
O
Me
80
O
S
(E,E/E,Zz2:1)c
Ph
N
N
O
S
N
Ph
O
OH
O
Me
O
Me
OH
84
S
S
(E,E/E,Zz2:1)c
Ph
N
Ph
O
O
Me
O
Ph
37 (75)d
(E)
10
4
5
8j
Ph
Ph
Ph
O
N
N
O
OH

B.A. Trofimov et al. / Tetrahedron 66 (2010) 7527e7532
7529
Table 1 (continued)
Entry
Oximes 1e4
Acylacetylenes 5e7
Product 8ael
Isolated yields,b
% (isomer)
O
76
(E)
O
S
11
4
4
6
7
8k
8l
Ph
Ph
O
N
O
N
N
O
O
Ph
O
OH
OH
63 (79)e
(E)
12
S
N
O
Ph
a
Reagents and conditions: 1e4 (2 mmol), 5e7 (2 mmol), Ph3P (0.2 mmol), CH2Cl2 (5 mL), rt, 7 h, under Ar.
The yield was calculated by the ketoxime consumed.
b
c
2-Acetylthiophene oxime 3 was used as a mixture of (E)- and (Z)-isomers in a ratio of E:Zz2:1 (1H, 13C NMR).
Based in the reacted oxime, conversion of which was 50% (1H NMR).
d
e
Based in the reacted oxime, conversion of which was 80% (1H NMR).
Theoretically, (O)-2-(acyl)vinylketoximes 8aei can exist as four
that is typical for the O-vinyloxime fragments C]NeOeC]C.9 In
the case of the possible nitrone form [C]N(/O)eC]C], the 15N
NMR resonance should be pronouncedly high-field shifted (up to
ꢁ100 ppm).9 The vinyl proton in (E)-isomers (A and B, Scheme 1)
resonates in the region 7.02e7.21 ppm. The spinespin coupling
constant between the proton and Ci of the phenyl ring 3JHeCi equals
6.6e6.8 Hz and is indicative of the trans-configuration of the
isomers.10
Configuration assignments for the oxime fragments of com-
pounds 8aei have been done using analysis of the 1H and 13C
chemical shifts in the NMR spectra of the methyl group. These
values are in good agreement with known data on chemical shifts
of the methyl moieties in 1H and 13C NMR spectra for (E)- and (Z)-
isomers of O-vinylketoximes.11
The presence of (Z)-ketovinyl isomers (C and D, Scheme 1) and
their relative content in the crude product follows from the vinyl
proton resonance in the region 6.16e6.36 ppm in the 1H NMR
spectra (3JHeCiz3.5 Hz). This confirms the cis-configuration of the
vinyl proton and phenyl ring10 that is supported by the data of 2D
NOESY experiments.
spatial isomers AeD (Scheme 1) differing in the location of the
carbonyl moiety and oxygen atom at the double bond ((E)-or (Z)) as
well as in the position of oxygen atom and senior substitutent
relative to the C]N bond in the oxime fragment of the molecule
((E)- or (Z)).
O
O
R3
R1
R3
Me
R1
N
N
Ph
O
Ph
O
Me
A (E,E)
B (E,Z)
O
O
R3
N
R3
N
R1
Me
R1
Ph
O
Ph
O
Me
C (Z,E)
D (Z,Z)
Scheme 1. Possible isomers of (O)-2-(acyl)vinylketoximes 8.
The NMR monitoring of isomers 8a (E,E), 8i (E,Z), and 8k (E) in-
terconversion has been performed in CDCl3 at room temperature to
check their thermodynamic stability. It has been found that none of
the compounds studied undergo the isomeric transformations in the
oxime part of the molecules. However, in the ketovinyl group, (E)/
(Z)-isomerization (up to 40% for 1.5 month, E:Z ratio z3:2) occurred,
indicated by the appearance of high-field signals of the vinyl proton
The experiments have shown that the reaction of ketoximes 1e4
with acylacetylenes 5e7 proceeds with high (E)-stereoselectivity
for the ketovinyl function formation (isomers A and B, Scheme 1).
The relative content of (Z)-isomers (C and D) in the crude product
for compounds 8aei did not exceed 8%, the total conversion being
96e100% (1H NMR). In the case of ketoximes 1,2 (presented by (E)-
isomers with respect to the C]N bond), only (E,E)-isomers A of the
corresponding oximes 8aef were isolated. For 2-acetylthiophene
oxime 3 (a mixture of (E)- and (Z)-isomers in a ratio of z2:1),
compounds 8gei were obtained as a mixture of (E,E)- (A) and (E,Z)-
isomers (B) (Scheme 1) in a ratio of z2:1 (1H NMR). Individual
(E,E)- and (E,Z)-isomers of compounds 8h and 8i were isolated by
fractional recrystallization from petroleum ether (70e100 ꢀC).
Evidently, the nature and bulk of the substituents in starting
oximes 1e4 do not practically affect their ability to be added to the
triple bond of acylacetylenes, more exactly the isolated yields of the
adducts 8aei (Table 1).
CH] (d 6.25, 6.30, and 6.24 ppm for compounds 8a, 8i, and 8k, re-
spectively; 3JHeCiz3.5 Hz) in the 1H NMR spectra as well as by dou-
bling of the other signals in the 1H and 13C NMR spectra. In this case,
the values of chemical shifts 13C of the methyl group for compounds
8a and 8i remained almost the same (Δdz1 ppm) that evidences to
the preservation of initial configuration of the oxime fragment, the
configuration of the ketovinyl part being significantly changed. The
monitoring of compound 8i, employed in the reaction as a mixture of
(E,E)- and (E,Z)-isomers in a ratio of z2:1 (A and B, Scheme 1) have
demonstrated the similar behavior. In this experiment, we observed
all four possible isomeric forms of compound 8i (AeD, Scheme 1).
(E)/(Z) Isomerization of the ketovinyl fragment upon storage of the
adduct is proved by the emergence (1H NMR spectra) of two new
signals CH] at 6.26 and 6.30 ppm, assignable to (Z,E)- and (Z,Z)-iso-
mers of compound 8i (C and D, Scheme 1) in a ratio of z2:1. The
retention of the isomeric ratio under partial (E,E)/(Z,E) and (E,Z)/
(Z,Z) isomerization is indicative of the independence of this process
from the configuration of the oxime fragment.
The reaction of acylacetylenes 5e7 with cyclohexanone oxime 4
under the same conditions was not so unambiguous. The yields of
the corresponding O-vinyloximes 8l and 8j were 63 and 37%, re-
spectively (Table 1). Attempts to improve the latter result by in-
creasing the loading to 20 mol % triphenylphosphine and increasing
the reaction time to 40 h was not fully successful (the yield of 8j
does not exceeding 36%, 1H NMR).
In the 15N NMR spectra of compounds 8ael, the values of
chemical shifts of nitrogen atoms range from ꢁ15.7 to ꢁ31.1 ppm
Thus, the results obtained testify that the (E)-stereoselectivity
relative to the C]C bond is kinetically controlled. The (E)-isomers

7530
B.A. Trofimov et al. / Tetrahedron 66 (2010) 7527e7532
are energetically less favorable than the corresponding (Z)-isomers.
Eventually, the (E)-isomers even at room temperature are gradually
transformed to (Z)-isomers, approaching the thermodynamical
equilibrium with isomers in the ratio of E:Zz3:2. In the case of
oxime 8a it has been shown that the equilibrium (1H NMR) is
reached after 17 h (C6D6 at 60e63 ꢀC), and further heating does not
change the isomers ratio.
aldehydes by the Yozych reaction with subsequent oxidation of the
alcohols with active MnO2 according to the protocol.5a
4.2. General procedure for synthesis of O-vinyloximes (8ael)
A
mixture of ketoxime 1e4 (2 mmol), acylacetylene 5e7
(2 mmol), and Ph3P (52 mg, 0.2 mmol) in CH2Cl2 (5 mL) was stirred
at rt for 7 h under Ar and then the solution was evaporated. The
crystalline products were ground in Et2O (5 mL) and allowed to
stand at ꢁ12/ꢁ8 ꢀC overnight. The residue was filtered off, dried
under vacuum, and recrystallized from hexane or petroleum ether.
Compound 8j was purified by column chromatography on Al2O3
using Et2O/hexane (1:3) as eluent.
The published data on the properties of trivalent phosphorus
nucleophiles6b,12 allows one to assume that O-vinyloximes 8ael are
generated due to the initial attack of triphenylphosphine at b-car-
bon atom of acylacetylene 5e7.
The high stereoselectivity of the reaction, i.e., the predominant
formation of (E)-adducts (i.e., violation of the ‘trans-nucleophilic
addition’ rule13) can be rationalized as follows. Normally, nucleo-
philic addition of triphenylphosphine to acetylenes 5e7 should
lead to the zwitterion E of trans-configuration (in accordance with
‘trans-nucleophilic addition’ rule13). However, this zwitterion is
easily isomerized to its cis-form (G1#G2) via allenolate zwitterion
F due to a strong attractive electrostatic interaction between neg-
ative and positive charges up to the possible closing up the three-
membered ring G2. When the zwitterion (G1#G2) is attacked by
the ketoxime molecule, its carbanionic center is quenched to result
in the formation of the intermediate phosphonium salt H, which
then is transformed into the target O-vinyloximes 8ael (Scheme 2).
This is accompanied by the releasing of triphenylphosphine and its
returning as a catalyst to the reaction mixture.
4.2.1. (E)-1,3-Diphenyl-3-({[(E)-1-phenylethylidene]amino}oxy)-2-
propen-1-one (8a). Yield: 0.57 g (83%); pale yellow crystals, mp
82e84 ꢀC (hexane); [Found: C, 80.8; H, 5.6; N, 4.0. C23H19NO2 re-
quires C, 80.92; H, 5.61; N, 4.10%]; nmax(KBr) 1663, 1584, 1560 cmꢁ1
;
dH (400.1 MHz, CDCl3) 2.46 (s, 3H, CH3), 7.17 (s, 1H, CH]), 7.41e7.97
(m, 15H, Ar); dC (100.6 MHz, CDCl3) 14.0, 101.1, 126.7, 127.9, 128.2,
128.6, 129.6, 130.2, 130.9, 131.4, 131.9, 133.5, 135.0, 139.6, 160.9,
168.4, 190.6; dN (40.5 MHz, CDCl3) ꢁ16.4.
4.2.2. (E)-1-(2-Furyl)-3-phenyl-3-({[(E)-1-phenylethylidene]amino}
oxy)-2-propen-1-one (8b). Yield: 0.55 g (83%); pale yellow crystals,
mp 112e114 ꢀC (hexane); [Found: C, 76.4; H, 5.1; N, 4.2. C21H17NO3
Ph
P
R3
Ph3P
Ph
Ph
Ph
O
Ph3P
R3
O
Ph3P
Ph
O
Ph3P
5-7
R3
.
O
Ph
Ph
R3
G1
E
G2
F
O
Ph3P
Ph
1-4
N
G1
G2
8a-l
-Ph3P
O
R2 R1
R3
H
Scheme 2. Tentative mechanism for the reaction of ketoximes with acylacetylenes in the presence of Ph3P.
3. Conclusion
requires C, 76.12; H, 5.17; N, 4.23%]; nmax(KBr) 1648, 1586,
1569 cmꢁ1
dH (400.1 MHz, CDCl3) 2.45 (s, 3H, CH3), 6.50 (dd,
;
In conclusion, a facile and convenient approach to the synthesis
of hitherto unknown (O)-2-(acyl)vinylketoximes has been de-
veloped. The oximes obtained are promising building blocks and
monomers for organic synthesis, ligands for new metal-complex
catalysts as well as the models for studying the reactivity of the
O-vinyloxime function.
3J¼3.6, 1.7 Hz, 1H, H4furyl), 7.15 (dd, 3J¼3.6 Hz, 4J¼0.7 Hz, 1H,
H3furyl),7.17 (s, 1H, CH]), 7.43e7.84 (m, 11H, Ar, HetAr); dC
(100.6 MHz, CDCl3) 14.2, 99.7, 112.1, 115.8, 126.9, 127.9, 128.8, 129.4,
130.2, 130.6, 133.5, 135.1, 145.4, 154.6, 161.2, 169.0, 178.1; dN
(40.5 MHz, CDCl3) ꢁ16.7.
4.2.3. (E)-1-(2-Thienyl)-3-phenyl-3-({[(E)-1-phenylethylidene]
amino}oxy)-2-propen-1-one (8c). Yield: 0.59 g (85%); pale yellow
crystals, mp 117e118 ꢀC (petroleum ether 40e70 ꢀC); [Found: C,
72.2; H, 4.5; N, 4.1; S, 9.1. C21H17NO2S requires C, 72.60; H, 4.93; N,
4. Experimental
4.1. General
4.03; S, 9.23%]; nmax(KBr) 1639, 1585, 1565 cmꢁ1
; dH (400.1 MHz,
The IR spectra were recorded on a Bruker IFS25 spectropho-
tometer from samples prepared as KBr pellets. The NMR spectra
were measured from solutions in CDCl3 on Bruker DPX-400 and AV-
400 spectrometers (400.1 MHz for 1H, 100.6 MHz for 13C, and
40.5 MHz for 15N) using hexamethyldisiloxane (1H, 13C) and nitro-
CDCl3) 2.45 (s, 3H, CH3), 7.10 (dd, 3J¼4.8, 3.7 Hz,1H, H4thienyl), 7.16 (s,
1H, CH]), 7.44e7.85 (m, 12H, Ar, HetAr); dC (100.6 MHz, CDCl3)
13.8, 99.9, 126.5, 127.5, 127.6, 128.4, 129.0, 129.8, 130.2, 130.4, 132.2,
133.1, 134.7, 147.1, 160.8, 168.2, 181.7.
methane (15N) as internal references. The assignments of 1H and 13
C
4.2.4. (E)-3-({[(E)-1-(2-Naphthyl)ethylidene]amino}oxy)-1,3-di-
phenyl-2-propen-1-one (8d). Yield: 0.64 g (82%); pale yellow crys-
tals, mp 71e73 ꢀC (hexane); [Found: C, 83.0; H, 5.5; N, 3.5.
C27H21NO2 requires C, 82.84; H, 5.41; N, 3.58%]; nmax(KBr) 1658,
NMR spectra were performed by COSY, NOESY, HSQC, and HMBC
experiments.
Solvents were purified and dried using reported methods14 and
stored over 4 Åmolecularsieves. Oximes 1,4 arecommercialproducts.
Oximes 2,3 were prepared by the known procedure.15 Acylacetylenes
5e7 were synthesized from phenylacetylene and the corresponding
1581, 1567 cmꢁ1
; dH (400.1 MHz, CDCl3) 2.57 (s, 3H, CH3), 7.22 (s,
1H, CH]), 7.39e8.20 (m,17H, Ar); dC (100.6 MHz, CDCl3) 14.0,101.5,
123.6, 126.8, 127.4, 127.5, 127.9, 128.1, 128.4, 128.5, 128.6, 128.8,

B.A. Trofimov et al. / Tetrahedron 66 (2010) 7527e7532
7531
129.5, 130.2, 132.2, 132.5, 133.1, 133.7, 134.4, 139.8, 160.8, 168.6,
191.0; dN (40.5 MHz, CDCl3) ꢁ15.8.
1642,1582,1567 cmꢁ1
;
dH (400.1 MHz, CDCl3) ((E,E)-isomer) 2.43 (s,
3H, CH3), 7.11 (m, 2H, H4thienyl), 7.15 (s, 1H, CH]), 7.39e7.74 (m, 9H,
Ar, HetAr); for (E,Z)-isomer: 2.58 (s, 3H, CH3), 7.11 (m, 2H, H4thienyl),
7.18 (s, 1H, CH]), 7.43e7.77 (m, 9H, Ar, HetAr); dC (100.6 MHz,
CDCl3) ((E,E)-isomer) 14.2, 100.4, 127.5, 127.9, 128.9, 129.1, 129.5,
130.2, 130.8, 132.6, 133.2, 138.5, 147.5, 156.6, 168.3, 181.8; for (E,Z)-
isomer: 20.2, 100.5, 126.2, 127.5, 127.9, 128.6, 129.7, 130.2, 130.9,
131.6, 132.1, 132.6, 133.0, 147.5, 152.0, 168.4, 182.1.
4.2.5. (E)-1-(2-Furyl)-3-({[(E)-1-(2-naphthyl)ethylidene]amino}
oxy)-3-phenyl-2-propen-1-one (8e). Yield: 0.63 g (83%); pale yellow
crystals, mp 75e77 ꢀC (hexane); [Found: C, 79.1; H, 5.3; N, 3.5.
C25H19NO3 requires C, 78.72; H, 5.02; N, 3.67%]; nmax(KBr) 1654,
1587, 1562 cmꢁ1
; dH (400.1 MHz, CDCl3) 2.56 (s, 3H, CH3), 6.51 (dd,
3J¼3.6, 1.7 Hz, 1H, H4furyl), 7.16 (dd, 3J¼3.6 Hz, 4J¼0.7 Hz, 1H, H3furyl),
7.21 (s, 1H, CH]), 7.45e8.20 (m, 13H, Ar, HetAr); dC (100.6 MHz,
CDCl3) 14.1, 99.8, 112.2, 115.9, 123.6, 126.8, 127.5, 127.9, 128.0, 128.5,
128.8, 129.5, 130.3, 132.5, 133.1, 133.5,134.4, 145.5, 154.7, 161.1, 169.1,
178.2; dN (40.5 MHz, CDCl3) ꢁ15.7.
4.2.10. Cyclohexanone O-[(E)-3-oxo-1,3-diphenyl-1-propenyl]oxime
(8j). Yield: 0.24 g (37%); colorless crystals, mp 77e79 ꢀC (hexane);
[Found: C, 78.6; H, 6.4; N, 4.5. C21H21NO2 requires C, 78.97; H, 6.63;
N, 4.39%]; Rf (25% Et2O/hexane) 0.13; nmax(KBr) 2936, 1657, 1583,
1564 cmꢁ1
; dH (400.1 MHz, CDCl3) 1.69 (m, 4H, CH2), 1.82 (m, 2H,
4.2.6. (E)-3-({[(E)-1-(2-Naphthyl)ethylidene]amino}oxy)-3-phenyl-
1-(2-thienyl)-2-propen-1-one (8f). Yield: 0.67 g (84%); pale yellow
crystals, mp 109e110 ꢀC (petroleum ether 70e100 ꢀC); [Found: C,
75.6; H, 4.9; N, 3.2; S, 8.2. C25H19NO2S requires C, 75.54; H, 4.82; N,
CH2), 2.43 (m, 2H, CH2), 2.62 (m, 2H, CH2), 7.03 (s, 1H, CH]),
7.36e7.94 (m, 10H, Ar); dC (100.6 MHz, CDCl3) 25.6, 26.0, 26.8, 27.1,
32.3, 100.3, 127.9, 128.2, 128.4, 129.4, 129.9, 131.9, 140.0, 167.3, 169.7,
190.6.
3.52; S, 8.07%]; nmax(KBr) 1642, 1591, 1570 cmꢁ1
; dH (400.1 MHz,
CDCl3) 2.57 (s, 3H, CH3), 7.11 (dd, 3J¼4.8, 3.7 Hz, 1H, H4thienyl), 7.21
(s, 1H, CH]), 7.45e8.20 (m, 14H, Ar, HetAr); dC (100.6 MHz, CDCl3)
14.0, 100.5, 123.5, 126.8, 127.4, 127.8, 127.9, 128.0, 128.5, 128.8, 129.5,
130.2, 130.9, 132.5, 132.6, 133.1, 133.5, 134.4, 135.8, 147.5, 160.9,
168.7, 182.1; dN (40.5 MHz, CDCl3) ꢁ15.7.
4.2.11. Cyclohexanone O-[(E)-3-(2-furyl)-3-oxo-1-phenyl-1-propenyl]
oxime (8k). Yield: 0.47 g (76%); colorless crystals, mp 104e106 ꢀC
(hexane); [Found: C, 73.6; H, 5.9; N, 4.5. C19H19NO3 requires C,
73.77; H, 6.19; N, 4.53%]; nmax(KBr) 2934, 1654, 1585, 1569 cmꢁ1
; dH
(400.1 MHz, CDCl3) 1.68 (m, 4H, CH2), 1.82 (m, 2H, CH2), 2.44 (m,
2H, CH2), 2.60 (m, 2H, CH2), 6.48 (dd, 3J¼3.6, 1.7 Hz, 1H, H4furyl), 7.02
(s, 1H, CH]), 7.11 (dd, 3J¼3.6 Hz, 4J¼0.7 Hz, 1H, H3furyl), 7.40e7.57
(m, 6H, Ar, HetAr); dC (100.6 MHz, CDCl3) 25.6, 26.0, 26.8, 27.1, 32.3,
98.6, 112.1, 115.6, 127.9, 129.4, 130.0, 133.8, 145.3, 154.8, 167.6, 169.6,
178.1; dN (40.5 MHz, CDCl3) ꢁ31.1.
4.2.7. (E)-1,3-Diphenyl-3-({[(E)-1-(2-thienyl)ethylidene]amino}oxy)-
2-propen-1-one and (E)-1,3-diphenyl-3-({[(Z)-1-(2-thienyl)ethylidene]
amino}oxy)-2-propen-1-one (8g). Yield: 0.57 g (82%); pale yellow
crystals, mp 78e85 ꢀC (for mixture of (E,E)- and (E,Z)-isomers);
[Found: C, 72.2; H, 4.8; N, 4.1; S, 9.1. C21H17NO2S requires C, 72.60;
H, 4.93; N, 4.03; S, 9.23%]; nmax(KBr) 1667, 1583, 1573 cmꢁ1
;
dH
4.2.12. Cyclohexanone O-[(E)-3-oxo-1-phenyl-3-(2-thienyl)-1-pro-
penyl]oxime (8l). Yield: 0.41 g (63%); pale yellow crystals, mp
90e92 ꢀC (hexane); [Found: C, 69.9; H, 5.8; N, 4.4; S, 9.6.
C19H19NO2S requires C, 70.12; H, 5.88; N, 4.30; S, 9.85%]; nmax(KBr)
(400.1 MHz, CDCl3) (for mixture of (E,E)- and (E,Z)-isomers) 2.46 (s,
3H, CH3, E,E), 2.57 (s, 3H, CH3, E,Z), 7.12 (m, 2H, H4thienyl), 7.16 (s, 1H,
CH], E,E), 7.19 (s, 1H, CH], E,Z), 7.40e7.98 (m, 24H, Ar, HetAr); dC
(100.6 MHz, CDCl3) (for mixture of (E,E)- and (E,Z)-isomers) 14.1
(CH3, E,E), 20.1 (CH3, E,Z),101.2,101.4,126.1,127.4, 127.8,127.9,128.2,
128.3, 128.8, 129.0, 129.3, 129.6, 130.0, 131.9, 132.0, 132.8, 139.6,
156.4, 168.1, 190.4.
2934, 1632, 1584, 1562 cmꢁ1
; dH (400.1 MHz, CDCl3) 1.65 (m, 4H,
CH2), 1.79 (m, 2H, CH2), 2.41 (m, 2H, CH2), 2.59 (m, 2H, CH2), 7.03 (s,
1H, CH]), 7.09 (dd, 3J¼4.8, 3.7 Hz, 1H, H4thienyl), 7.43e7.74 (m, 7H,
Ar, HetAr); dC (100.6 MHz, CDCl3) 25.6, 25.9, 26.8, 27.1, 32.2, 99.2,
127.8, 127.9, 129.3, 130.0, 130.6, 132.3, 133.8, 147.7, 167.5, 169.2,
182.0; dN (40.5 MHz, CDCl3) ꢁ31.1.
4.2.8. (E)-1-(2-Furyl)-3-phenyl-3-({[(E)-1-(2-thienyl)ethylidene]
amino}oxy)-2-propen-1-one and (E)-1-(2-furyl)-3-phenyl-3-({[(Z)-1-
(2-thienyl)ethylidene]amino}oxy)-2-propen-1-one (8h). Yield: 0.54 g
(80%); mp 88e102 ꢀC (for mixture of (E,E)- and (E,Z)-isomers); pale
yellow crystals, mp 108e110 ꢀC (for (E,E)-isomer from petroleum
ether 70e100 ꢀC); (E,Z)-isomer is a viscous oil; [Found: C, 67.3; H,
4.4; N, 4.2; S, 9.2. C19H15NO3S requires C, 67.64; H, 4.48; N, 4.15; S,
Acknowledgements
The work has been carried out under financial support of lead-
ing scientific schools by the President of the Russian Federation
(Grant NSH 3230-2010.3).
9.50%]; nmax(KBr) 1650, 1584, 1571 cmꢁ1
; dH (400.1 MHz, CDCl3)
((E,E)-isomer) 2.45 (s, 3H, CH3), 6.50 (dd, 3J¼3.6, 1.7 Hz, 1H, H4furyl),
7.11 (s, 1H, CH]), 7.12e7.15 (m, 2H, H4thienyl, H3furyl), 7.40e7.62 (m,
8H, Ar, HetAr); for (E,Z)-isomer: 2.57 (s, 3H, CH3), 6.50 (dd, 3J¼3.6,
1.7 Hz, 1H, H4furyl), 7.10 (dd, 3J¼4.4, 3.4 Hz, 1H, H4thienyl), 7.15 (dd,
3J¼3.2 Hz, 4J¼0.7 Hz, 1H, H3furyl), 7.18 (s, 1H, CH]), 7.42e7.68 (m,
8H, Ar, HetAr); dC (100.6 MHz, CDCl3) ((E,E)-isomer) 13.7, 99.3,111.6,
115.4, 127.0, 127.4, 128.5, 128.6, 128.9, 129.7, 132.8, 137.9, 145.1, 154.1,
156.2, 168.1, 177.4; for (E,Z)-isomer: 20.1, 99.9, 112.2, 115.9, 126.2,
127.4, 128.5, 129.4, 129.7, 130.1, 132.1, 132.9, 145.5, 154.7, 156.6,
168.8, 178.0.
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