A new synthetic approach to α-chlorocinnamaldehydes

Article abstract of DOI:10.1055/s-2004-837303

A new simple and efficient transformation of aromatic aldehydes into α-chlorocinnamaldehydes is described. Catalytic olefination reaction of hydrazones of aromatic aldehydes with 2-trichloromethyl-1,3-dioxolane gives ethylene acetals of target alkenes in moderate to good yields. The reaction proceeds stereoselectively to form preferably Z-isomers.

Full text of DOI:10.1055/s-2004-837303

PAPER
605
A New Synthetic Approach to a-Chlorocinnamaldehydes
1
-Chlorocinnamald
a
ehydes lentine G. Nenajdenko,*a Alexander L. Reznichenko,a Olesya N. Lenkova,a Alexey V. Shastin,b
Elizabeth S. Balenkovaa
a
Moscow State University, Department of Chemistry, Leninskie Gory, Moscow 119992, Russia
Institute of Problems of Chemical Physics, Chernogolovka, Moscow region, 142432, Russia
b
Fax +7(095)9328846; E-mail: nen@acylium.chem.msu.ru
Received 20 October 2004
This article is devoted to the synthesis of a-chlorocinnam-
aldehydes using catalytic olefination. a-Chlorocinnamal-
dehydes can be used as valuable building blocks for the
synthesis of various heterocyclic systems.5 Previously
Abstract: A new simple and efficient transformation of aromatic
aldehydes into a-chlorocinnamaldehydes is described. Catalytic
olefination reaction of hydrazones of aromatic aldehydes with 2-
trichloromethyl-1,3-dioxolane gives ethylene acetals of target alk-
enes in moderate to good yields. The reaction proceeds stereoselec- such compounds have been prepared using the Wittig ap-
proach,6 HCl elimination from 2,3-dichloro-3-arylpropi-
tively to form preferably Z-isomers.
onaldehydes,7 addition of 1-chloro-2,2-difluoro-
Key words: catalytic olefination, a-chlorocinnamaldehydes, catal-
vinyllithium to benzaldehyde,8 chlorination of corre-
ysis, alkenes, 2-trichloromethyl-1,3-dioxolane
sponding cinnamaldehydes9 and thermal elimination of
sulfinyl group from a-halo-a-sulfinylaldehydes.10
Olefination of carbonyl compounds, the R1R2C=O →
We tried to use chloral as a polyhalogenated synthon in
COR to prepare the corresponding a-chlorocinnamalde-
hydes. The hydrazone of 4-chlorobenzaldehyde was cho-
R1R2C=CXY transformation, is one of the most success-
ful synthetic routes to a variety of substituted alkenes.1 In
addition, many natural products possess various trisubsti-
tuted alkene moieties, and highly stereoselective con-
struction of trisubstituted alkenes is one of the most
challenging problems in synthetic organic chemistry.2 Al-
though many efficient and selective synthetic methods for
the preparation of this important structural fragment have
been devised for decades, there is still the need for a gen-
eral and stereoselective method for an efficient synthesis
of trisubstituted alkenes.
sen as a model substrate. We have found that chloral could
not be used as a reagent in COR because no formation of
a-chlorocinnamaldehyde takes place. In the presence of
chloral, the hydrazone is converted into corresponding
sym-azine (according to GC/MS of reaction mixture). To
modify the polyhalogenated synthon, we protected the
chloral carbonyl group by transformation of chloral into
2-trichloromethyl-1,3-dioxolane. We started our investi-
gation from optimization of reaction conditions because
nature of solvent, base and amount of catalyst used in
COR can influence the yield of product dramatically.
Variation of bases (ammonia, ethylenediamine, triethyl-
amine) in DMSO and ethanol as solvents shows that the
optimal conditions are application of ethylenediamine as
a base and DMSO as a solvent. We studied also the
amount of catalyst and found higher yield of product in
the case of 10% of CuCl as a catalyst. We also tried to ex-
plore one-pot technique for the preparation of ethylene ac-
etals of a-chlorocinnamaldehydes to avoid preliminary
preparation of hydrazones. It was found that generally the
yield of target product prepared with one-pot technique
was almost the same as from hydrazone, but one-pot syn-
thesis is more simple and preferable (Scheme 1).
Recently, we elaborated a novel approach to alkene syn-
thesis, called catalytic olefination reaction (COR) of alde-
hydes and ketones.3 It was found that N-unsubstituted
hydrazones of carbonyl compounds could be smoothly
converted to various substituted alkenes by treatment with
polyhalogenoalkanes in the presence of catalytic amounts
of CuCl. Based on COR we elaborated novel methods of
synthesis of dichloroalkenes, dibromoalkenes, vinyl bro-
mides, vinyl iodides, fluorine-containing alkenes, 1-chlo-
rocinnamonitriles and 1-chlorocinnamates from aromatic
and heteroaromatic carbonyl precursors. A possible
mechanism of olefination was discussed and a catalytic
cycle of COR was reported earlier.4
Scheme 1
SYNTHESIS 2005, No. 4, pp 0605–0609
x
x
.
x
x
.2
0
0
5
Advanced online publication: 23.12.2004
DOI: 10.1055/s-2004-837303; Art ID: P12704SS
© Georg Thieme Verlag Stuttgart · New York

606
V. G. Nenajdenko et al.
PAPER
gel (63–200 mesh, Merck). All starting materials are commercially
available.
Having found the optimal reaction conditions, we investi-
gated the conversion of wide range of aromatic and het-
eroaromatic aldehydes to the corresponding ethylene 2-Trichloromethyl-1,3-dioxolane was prepared according to the lit-
erature procedure.11
acetals of a-chlorocinnamaldehydes. In general, the reac-
tion proceeded smoothly to give the target products 3 in
Acetals 3; General Procedure
moderate to good yields (Table 1). The reaction proceeds
A solution of aromatic aldehyde 1 (3 mmol) in DMSO (3 mL) was
also stereoselectively affording preferably the Z-isomers.
added dropwise to 100% N2H4·H2O (0.15 mL, 3 mmol) and the mix-
The configuration of alkene 4a was determined by com-
ture was stirred until the aldehyde had disappeared (TLC monitor-
ing). Then CuCl (30 mg, 0.03 mmol) and ethylenediamine (1.0 mL,
15 mmol) were added. After 5 min, a solution of 2-trichloromethyl-
1,3-dioxolane (2.8 g, 15 mmol) in DMSO (2 mL) was added drop-
wise at 20 °C. The reaction mixture was stirred for 24 h, then
quenched with 5% HCl (100 mL) and extracted with CH2Cl2 (3 × 50
mL). The combined extracts were dried (Na2SO4), the CH2Cl2 was
evaporated in vacuo and the residue was purified by column chro-
matography (hexane–CH2Cl2) (Table 1). Separation of isomers by
column chromatography was not successful.
1
parison of its H NMR spectrum with literature data.10
Deprotection of acetals 3 with aqueous HCl (5%) in THF
gave target a-chlorocinnamaldehydes 4 in good yields
(Table 1). The Z/E ratios of both 3 and 4 were determined
by GC/MS. The Z/E isomer ratio is not changed after
elimination of protective acetal group. The stereochemis-
try of the olefination is generally in accordance with the
stereochemistry of COR observed earlier.3 Electron-do-
nating substituents in aromatics (Table 1) give better ste-
reoselectivity of olefination and ortho substitution in
benzene ring leads to decreased selectivity.
2-(1-Chloro-2-phenylvinyl)-1,3-dioxolane (3a)
White solid; mixture of Z/E isomers (9:1); Rf 0.20 (hexane–CH2Cl2,
1:2); mp 61 °C.
Table 1 a-Chlorocinnamaldehydes 4 and Acetals 3 Prepared
IR (Nujol): 1644 cm–1 (C=C).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 7.70–7.64 (m, 2 H),
7.41–7.29 (m, 3 H), 6.91 (s, 1 H, HC=), 5.53 (s, 1 H), 4.20–4.12 (m,
2 H), 4.06–3.98 (m, 2 H).
Product
Aryl
Z/E
Yield 3
Yield 4
(%)a
(%)a
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 133.5, 130.2, 129.5,
a
b
c
d
e
f
C6H5
9:1
64
70
67
48
69
70b
50
48
65
66
63
21
93
94
89
92
95
89
95
91
90
91
91
92
128.5, 128.2, 127.8, 104.4, 65.7 (CH2).
4-MeC6H4
4-ClC6H4
4-NO2C6H4
4-MeOC6H4
4-Me2NC6H4
2-NO2C6H4
2-MeOC6H4
3-BrC6H4
2-naphthyl
3-pyridyl
14:1
16:1
10:1
15:1
1:0
MS: m/z (%) = 210 (9), 175 (65), 131 (26), 77 (10), 73 (100).
Anal. Calcd for C11H11ClO2: C, 62.72; H, 5.26. Found: C, 62.30; H,
5.40.
2-[1-Chloro-2-(4-methylphenyl)vinyl]-1,3-dioxolane (3b)
White solid; mixture of Z/E isomers (14:1); Rf 0.20 (hexane–
CH2Cl2, 1:2); mp 62–63 °C.
IR (Nujol): 1640 cm–1 (C=C).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 7.58 (d, 2 H, J = 8.2
Hz), 7.17 (d, 2 H, J = 8.2 Hz), 6.86 (s, 1 H, HC=), 5.51 (s, 1 H),
4.20–4.12 (m, 2 H), 4.05–4.00 (m, 2 H), 2.35 (s, 3 H).
g
h
i
6:1
9:1
13:1
9:1
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 138.6, 131.2, 130.7,
129.5, 129.0, 127.8, 104.5, 65.7 (CH2), 21.3 (CH3).
j
MS: m/z (%) = 224 (20), 209 (22), 189 (59), 115 (26), 73 (100).
k
10:1
10:1
Anal. Calcd for C12H13ClO2: C, 64.15; H, 5.83. Found: C, 64.45; H,
5.89.
l
2-thienyl
a Isolated yields.
bAfter additional recrystallization (EtOH).
2-[1-Chloro-2-(4-chlorophenyl)vinyl]-1,3-dioxolane (3c)
White solid; mixture of Z/E isomers (16:1); Rf 0.23 (hexane–
CH2Cl2, 1:2); mp 52–53 °C.
In summary, we have elaborated a new approach to a-
chlorocinnamaldehydes and corresponding ethylene ace-
tals. Mild conditions, simplicity of the experimental tech-
nique and purification of products are remarkable
advantages of the presented method.
IR (Nujol): 1640 cm–1 (C=C).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 7.61 (d, 2 H, J = 8.4
Hz), 7.33 (d, 2 H, J = 8.4 Hz), 6.85 (s, 1 H, HC=), 5.51 (s, 1 H),
4.20–4.14 (m, 2 H), 4.05–3.99 (m, 2 H).
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 134.3, 132.0, 131.0,
130.7, 128.5, 126.5, 104.2, 65.8 (CH2).
Melting points are uncorrected. The IR spectra were measured us-
ing a UR-20 spectrometer. NMR spectra were recorded on Varian
VXR-400 spectrometer in CDCl3 with TMS as an internal standard.
GC-MS analyses were performed with an Finnigan SSQ 7000 Mass
Spectrometer connected to a Varian 3400 GC, equipped with a DB-
5MS column (30 m, 0.2 mm of internal diameter), EI at 70 eV and
He was used as the carrier gas. Merck 60F254 plates were used for
analytical TLC. Column chromatography was performed on silica
MS: m/z (%) = 244 (4), 209 (26), 73 (100).
Anal. Calcd for C11H10Cl2O2: C, 53.90; H, 4.11. Found: C, 53.73; H,
4.08.
2-[1-Chloro-2-(4-nitrophenyl)vinyl]-1,3-dioxolane (3d)
White solid; mixture of Z/E isomers (10:1); Rf 0.19 (hexane–
CH2Cl2, 1:2); mp 141 °C.
Synthesis 2005, No. 4, 605–609 © Thieme Stuttgart · New York

PAPER
1-Chlorocinnamaldehydes
607
IR (Nujol): 1521 (NO2), 1370 cm–1 (NO2).
MS: m/z (%) = 240 (9), 209 (4), 205 (35), 73 (100).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 8.21 (d, 2 H, J = 8.4
Hz), 7.80 (d, 2 H, J = 8.4 Hz), 6.98 (s, 1 H, HC=), 5.53 (s, 1 H),
4.25–4.12 (m, 2 H), 4.10–3.95 (m, 2 H).
Anal. Calcd for C12H13ClO3: C, 59.88; H, 5.44. Found: C, 59.83; H,
5.81.
2-[1-Chloro-2-(3-bromophenyl)vinyl]-1,3-dioxolane (3i)
Yellow oil; mixture of Z/E isomers (13:1); Rf 0.26 (hexane–CH2Cl2,
1:2).
IR (Nujol): 1615 cm–1 (C=C).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 7.81 (t, 1 H, J = 1.7
Hz), 7.58 (d, 1 H, J = 7.7 Hz), 7.44 (d, 1 H, J = 7.7 Hz), 7.23 (t, 1
H, J = 7.7 Hz), 6.84 (s, 1 H, HC=), 5.50 (s, 1 H), 4.19–4.11 (m, 2
H), 4.06–3.98 (m, 2 H).
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 140.0, 134.5, 130.2,
125.4, 123.5, 103.8, 65.9 (CH2).
MS: m/z (%) = 255 (2), 220 (37), 73 (100).
Anal. Calcd for C11H10ClNO4: C, 51.68; H, 3.94. Found: C, 51.37;
H, 3.87.
2-[1-Chloro-2-(4-methoxyphenyl)vinyl]-1,3-dioxolane (3e)
Yellow solid; of Z/E isomers (15:1); Rf 0.16 (hexane–CH2Cl2, 1:2);
mp 68 °C.
IR (Nujol): 1656 cm–1.
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 135.5, 132.2, 131.8,
131.5, 129.8, 128.0, 126.2, 122.3, 104.1, 65.8 (CH2).
MS: m/z (%) = 288 (2), 253 (14), 73 (100).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 7.65 (d, 2 H, J = 8.8
Hz), 6.88 (d, 2 H, J = 8.8 Hz), 6.82 (s, 1 H, HC=), 5.50 (s, 1 H),
4.20–4.14 (m, 2 H), 4.05–4.00 (m, 2 H).
Anal. Calcd for C11H11BrClO2: C, 45.63; H, 3.48. Found: C, 45.43;
H, 3.32.
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 159.6, 133.3, 131.0,
2-[1-Chloro-2-(2-naphthyl)vinyl]-1,3-dioxolane (3j)
Yellow solid; mixture of Z/E isomers (9:1); Rf 0.22 (hexane–
CH2Cl2, 1:2), mp 110 °C.
127.4, 113.6, 104.6, 65.7 (CH2), 55.2 (CH3).
MS: m/z (%) = 240 (45), 205 (93), 161 (31), 73 (100).
IR (Nujol): 1615 cm–1 (C=C).
Anal. Calcd for C12H13ClO3: C, 59.88; H, 5.44. Found: C, 59.93; H,
5.77.
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 8.15 (s, 1 H), 7.85–
7.78 (m, 4 H), 7.50–7.46 (m, 2 H), 7.06 (s, 1 H, HC=), 5.58 (s, 1 H),
4.23–4.15 (m, 2 H), 4.07–4.01 (m, 2 H).
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 133.1, 133.1, 131.0,
130.5, 129.4, 128.4, 127.9, 127.8, 127.6, 126.8, 126.6, 126.3, 104.5,
65.8 (CH2).
2-[(Z)-1-Chloro-2-(4-dimethylaminophenyl)vinyl]-1,3-diox-
olane (3f)
Yellow solid; Rf 0.43 (CH2Cl2); mp 129 °C (EtOH).
IR (Nujol): 1613 cm–1 (C=C).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 7.64 (d, 2 H, J = 8.4
Hz), 7.76 (s, 1 H, HC=), 6.68 (d, 2 H, J = 8.4 Hz), 5.50 (s, 1 H),
4.17–4.14 (m, 2 H), 4.02–3.98 (m, 2 H), 2.98 (s, 6 H).
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 142.7, 130.9, 128.1,
117.3, 111.6, 107.6, 105.0, 65.7 (CH2), 40.19 (CH3).
MS: m/z (%) = 260 (21), 225 (32), 183 (21), 151 (14), 73 (100).
Anal. Calcd for C15H13ClO2: C, 69.10; H, 5.03. Found: C, 68.75; H,
5.04.
3-[2-Chloro-2-(1,3-dioxolan-2-yl)vinyl]pyridine (3k)
Yellow liquid; mixture of Z/E isomers (10:1); Rf 0.22 (hexane–
EtOAc, 1:2).
IR (Nujol): 1653 cm–1 (C=C).
MS: m/z (%) = 253 (100), 218 (61), 121 (47), 73 (27).
Anal. Calcd for C13H6ClNO2: C, 61.54; H, 6.36. Found: C, 61.12;
H, 6.20.
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 8.75 (d, 1 H, J = 2.4
Hz), 8.56–8.52 (m, 1 H), 7.13 (s, 1 H, HC=), 8.16 (dt, 1 H, J = 8.0,
2.4 Hz), 7.33 (dd, 1 H, J = 8.0, 4.8 Hz), 6.89 (s, 1 H), 4.21–4.01 (m,
2 H), 4.07–4.01 (m, 2 H).
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 149.6, 148.1, 136.5,
133.2, 129.5, 123.7, 123.3, 103.6, 65.5 (CH2).
2-[1-Chloro-2-(2-nitrophenyl)vinyl]-1,3-dioxolane (3g)
Yellow solid; mixture of Z/E isomers (6:1); Rf 0.19 (hexane–
CH2Cl2, 1:2); mp 63 °C.
IR (Nujol): 1650 (C=C), 1528 (NO2), 1355 cm–1 (NO2).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 8.09 (d, 1 H, J = 9.6
Hz), 7.70–7.60 (m, 2 H), 7.48 (t, 1 H, J = 7.6 Hz), 7.32 (s, 1 H,
HC=), 5.61 (s, 1 H), 4.20–4.14 (m, 2 H), 4.05–4.00 (m, 2 H).
MS: m/z (%) = 211 (8), 176 (77), 132 (23), 73 (100).
Anal. Calcd for C10H10ClNO2: C, 56.75; H, 4.76. Found: C, 56.37;
H, 5.00.
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 147.5, 133.2, 132.2,
131.7, 129.5, 129.0, 124.6, 124.5, 103.1, 65.5 (CH2).
MS: m/z (%) = 254 (1), 220 (5), 73 (100).
2-[1-Chloro-2-(2-thienyl)vinyl]-1,3-dioxolane (3l)
Yellow solid; mixture of Z/E isomers (11:1); Rf 0.22 (hexane–
CH2Cl2, 1:2); mp 72 °C.
IR (Nujol): 1642 cm–1 (C=C).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 8.75 (s, 1 H), 8.53 (d,
1 H, J = 5.0 Hz), 8.15 (d, 1 H, J = 8.0 Hz), 7.33 (dd, 1 H, J = 8.0,
5.0 Hz), 6.89 (s, 1 H, HC=), 5.53 (s, 1 H), 4.16–4.10 (m, 2 H), 4.05–
3.99 (m, 2 H).
Anal. Calcd for C11H10ClNO4: C, 51.68; H, 3.94. Found: C, 51.37;
H, 3.89
2-[1-Chloro-2-(2-methoxyphenyl)vinyl]-1,3-dioxolane (3h)
Yellow oil; mixture of Z/E isomers (9:1); Rf 0.19 (hexane–CH2Cl2,
1:2).
IR (Nujol): 1651 cm–1 (C=C).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 7.91 (dd, 1 H,
J = 7.9, 1.7 Hz), 7.29 (t, 1 H, J = 7.9 Hz), 7.18 (s, 1 H, HC=), 6.96
(t, 1 H, J = 7.9 Hz), 6.87 (d, 1 H, J = 7.9 Hz), 5.56 (s, 1 H), 4.22–
4.13 (m, 2 H), 4.06–4.00 (m, 2 H), 3.82 (s, 1 H).
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 157.7, 130.3, 129.8,
123.3, 122.4, 120.0, 110.3, 104.6, 65.7 (CH2), 55.4 (CH3).
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 133.1, 133.1, 131.0,
130.5, 129.4, 128.4, 127.9, 127.8, 127.6, 126.8, 126.6, 126.3, 104.5,
65.8 (CH2).
MS: m/z (%) = 216 (37), 181 (100), 137 (41), 73 (72).
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Anal. Calcd for C9H9ClO2S: C, 49.89; H, 4.19. Found: C, 49.79; H,
4.14.
Anal. Calcd for C10H9ClO2: C, 61.08; H, 4.61. Found: C, 61.04; H,
4.67.
1-Chlorocinnamaldehydes 4; General Procedure
To a stirred solution of 3 (1 mmol) in THF (2 mL) was added 5% aq
HCl (1 mL). The reaction mixture was kept at 65 °C for 5 h, then
quenched by addition of H2O (30 mL) and extracted with CH2Cl2
(3 × 20 mL). The combined extracts were dried (Na2SO4), and the
CH2Cl2 was evaporated in vacuo to give the pure mixture of isomers
of 4.
(2Z)-2-Chloro-3-[4-dimethylaminophenyl]acrylaldehyde (4f)
White solid; Rf 0.54 (CH2Cl2); mp 103–105 °C.
IR (Nujol): 1680 (C=O), 1620 cm–1 (C=C).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 9.38 (s, 1 H, CHO),
7.91 (d, 2 H, J = 8.8 Hz), 7.37 (s, 1 H, HC=), 6.71 (d, 2 H, J = 8.8
Hz), 3.07 (s, 6 H).
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 186.4 (CHO), 152.3,
146.6, 133.6, 120.2, 111.4, 40.0 (CH3).
2-Chloro-3-(4-methylphenyl)acrylaldehyde (4b)
White solid; mixture of Z/E isomers (14:1); Rf 0.20 (hexane–
CH2Cl2, 1:2); mp 55–56 °C.
MS: m/z (%) = 209 (100), 208 (24), 144 (15), 121 (48).
Anal. Calcd for C11H12ClNO: C, 63.01; H, 5.77. Found: C, 63.37;
H, 5.52.
IR (Nujol): 1697 (C=O), 1602 cm–1 (C=C).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 9.47 (s, 1 H, CHO),
7.86 (d, 2 H, J = 7.9 Hz), 7.49 (s, 1 H, HC=), 7.28 (d, 2 H, J = 7.9
Hz), 2.41 (s, 3 H, CH3).
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 186.6 (CHO), 145.6,
142.4, 131.2, 129.6, 21.6 (CH3).
2-Chloro-3-(2-nitrophenyl)acrylaldehyde (4g)
White solid; mixture of Z/E isomers (9:1); Rf 0.18 (hexane–CH2Cl2,
1:2); mp 110 °C.
IR (Nujol): 1702 (C=O), 1611 (C=C), 1535 (NO2), 1363 cm–1
(NO2).
MS: m/z (%) = 180 (24), 165 (100), 115 (79), 91 (27), 89 (19).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 9.62 (s, 1 H, CHO),
8.23 (d, 1 H, J = 7.8 Hz), 8.05 (s, 1 H, HC=), 7.83 (d, 1 H, J = 7.8
Hz), 7.76 (t, 1 H, J = 7.8 Hz), 7.64 (t, 1 H, J = 7.8 Hz).
Anal. Calcd for C10H19ClO: C, 66.49; H, 5.02. Found: C, 66.62; H,
5.32.
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 185.9 (CHO), 147.5,
2-Chloro-3-(4-chlorophenyl)acrylaldehyde (4c)
White solid; mixture of Z/E isomers (16:1); Rf 0.23 (hexane–
CH2Cl2, 1:2); mp 72 °C.
IR (Nujol): 1698 (C=O), 1610 cm–1 (C=C).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 9.49 (s, 1 H, CHO),
7.89 (d, 2 H, J = 8.4 Hz), 7.49 (s, 1 H, HC=), 7.45 (d, 2 H, J = 8.4
Hz).
141.9, 135.2, 134.0, 131.4, 131.2, 128.3, 125.5.
MS: m/z (%) = 211 (26), 209 (100), 165(12), 101 (4).
Anal. Calcd for C9H6ClNO3: C, 51.08; H, 2.86. Found: C, 51.03; H,
2.76.
2-Chloro-3-(2-methoxyphenyl)acrylaldehyde (4h)
Yellow liquid; mixture of Z/E isomers (9:1); Rf 0.19 (hexane–
CH2Cl2, 1:2).
IR (Nujol): 1695 (C=O), 1605 cm–1 (C=C).
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 186.2, 143.6, 137.5,
132.2, 130.7, 129.2.
MS: m/z (%) = 200 (15), 165 (100), 139 (15), 136 (40), 101 (51).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 9.51 (s, 1 H, CHO),
8.31 (d, 1 H, J = 7.9 Hz), 8.03 (s, 1 H, HC=), 7.45 (t, 1 H, J = 7.9
Hz), 7.05 (t, 1 H, J = 7.9 Hz), 6.95 (d, 1 H, J = 7.9 Hz), 3.90 (s, 3 H,
CH3).
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 186.9 (CHO), 158.2,
140.2, 133.0, 132.0, 130.4, 121.3, 120.5, 110.7, 55.7 (CH3).
Anal. Calcd for C9H6Cl2O: C, 53.77; H, 3.01. Found: C, 53.61; H,
3.13.
2-Chloro-3-(4-nitrophenyl)acrylaldehyde (4d)
White solid; mixture of Z/E isomers (10:1); Rf 0.19 (hexane–
CH2Cl2, 1:2); mp 136–138 °C.
IR (Nujol): 1697 (C=O), 1525 (NO2), 1365 cm–1 (NO2).
MS: m/z (%) = 196 (66), 167 (30), 165 (100).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 9.55 (s, 1 H, CHO),
8.31 (d, 2 H, J = 8.8 Hz), 8.08 (d, 2 H, J = 8.8 Hz), 7.62 (s, 1 H,
HC=).
Anal. Calcd for C10H9ClO2: C, 61.08; H, 4.61. Found: C, 61.04; H,
4.67.
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 185.9 (CHO), 141.3,
2-Chloro-3-(3-bromophenyl)acrylaldehyde (4i)
Yellow liquid; mixture of Z/E isomers (13:1); Rf 0.26 (hexane–
CH2Cl2, 1.2).
IR (Nujol): 1700 (C=O), 1622 cm–1 (C=C).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 9.49 (s, 1 H, CHO),
8.09 (t, 1 H, J = 2.0 Hz), 7.85 (d, 1 H, J = 8.0 Hz), 7.50 (d, 1 H,
J = 8.0 Hz), 7.47 (s, 1 H, HC=), 7.35 (t, 1 H, J = 8.0 Hz).
138.1, 134.9, 131.5, 130.1, 123.9.
MS: m/z (%) = 211 (14), 194 (75), 164 (48), 101 (100), 75 (71).
Anal. Calcd for C9H6ClNO3: C, 51.08; H, 2.86. Found: C, 51.37; H,
2.60.
2-Chloro-3-(4-methoxyphenyl)acrylaldehyde (4e)
White solid; mixture of Z/E isomers (15:1); Rf 0.16 (hexane–
CH2Cl2, 1:2); mp 44–45 °C.
IR (Nujol): 1715 (C=O), 1635 cm–1 (C=C).
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 186.2 (CHO), 143.1,
134.2, 133.5, 133.0, 130.8, 130.3, 129.5, 122.9.
MS: m/z (%) = 246 (18), 244 (9), 165 (48), 29 (100).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 9.44 (s, 1 H, CHO),
7.95 (d, 2 H, J = 8.8 Hz), 7.46 (s, 1 H, HC=), 6.98 (d, 2 H, J = 8.8
Hz), 3.87 (s, 3 H, CH3).
Anal. Calcd for C9H6BrClO: C, 44.03; H, 2.46. Found: C, 44.02; H,
2.43.
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 186.5 (CHO), 162.2,
2-Chloro-3-(2-naphthyl)acrylaldehyde (4j)
White solid; mixture of Z/E isomers (9:1); Rf 0.19 (hexane–CH2Cl2,
1:2); mp 136–138 °C.
145.3, 133.3, 129.6, 125.1, 114.4, 55.5 (CH3).
MS: m/z (%) = 196 (89), 165 (29), 161 (23), 108 (100), 89 (51).
Synthesis 2005, No. 4, 605–609 © Thieme Stuttgart · New York

PAPER
1-Chlorocinnamaldehydes
609
IR (Nujol): 1695 (C=O), 1610 cm–1 (C=C).
Acknowledgment
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 9.55 (s, 1 H, CHO),
8.45 (s, 1 H), 8.04 (dd, 1 H, J = 6.8, 2.1 Hz), 7.93–7.85 (m, 3 H),
7.69 (s, 1 H, HC=), 7.61–7.53 (m, 2 H).
Financial support from Russian Fundamental Investigation Found-
ation (Grant 03-03-32052a) is gratefully acknowledged.
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 186.6 (CHO), 145.4,
134.4, 132.9, 132.5, 131.9, 129.8, 129.1, 128.5, 128.3, 127.7,
126.92, 126.86.
References
(1) (a) Kelly, S. E. In Comprehensive Organic Synthesis, Vol. 1;
Trost, B. M.; Fleming, I., Eds.; Pergamon: New York, 1999.
(b) Modern Carbonyl Olefination; Takeda, T., Ed.; Wiley:
Weinheim, 2004. (c) Korotchenko, V. N.; Nenajdenko, V.
G.; Balenkova, E. S.; Shastin, A. V. Russ. Chem. Rev. (Russ.
Transl.) 2004, 73, 1039.
MS: m/z (%) = 216 (25), 188 (25), 152 (100).
Anal. Calcd for C13H9ClO: C, 72.07; H, 4.19. Found: C, 72.26; H,
4.49.
2-Chloro-3-pyridin-3-ylacrylaldehyde (4k)
Yellow solid; mixture of Z/E isomers (10:1); Rf 0.19 (hexane–
CH2Cl2, 1:2); mp 55 °C.
IR (Nujol): 1695 (C=O), 1621 cm–1 (C=C).
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 9.53 (s, 1 H, CHO),
8.97 (s, 1 H), 8.67 (d, 1 H, J = 3.8 Hz), 7.45 (d, 1 H, J = 7.9 Hz),
7.55 (s, 1 H, HC=), 7,43 (dd, 1 H, J = 7.9, 3.9 Hz).
(2) Tago, K.; Kogen, H. Tetrahedron 2000, 56, 8825.
(3) Nenajdenko, V. G.; Korotchenko, V. N.; Shastin, A. V.;
Balenkova, E. S. Russ. Chem. Bull. 2004, 53, 1034.
(4) (a) Shastin, A. V.; Korotchenko, V. N.; Nenajdenko, V. G.;
Balenkova, E. S. Tetrahedron 2000, 56, 6557. (b) Shastin,
A. V.; Korotchenko, V. N.; Nenajdenko, V. G.; Balenkova,
E. S. Russ. Chem. Bull. 2001, 50, 1401. (c) Korotchenko,
V. N.; Shastin, A. V.; Nenajdenko, V. G.; Balenkova, E. S.
Tetrahedron 2001, 57, 7519. (d) Shastin, A. V.;
Korotchenko, V. N.; Nenajdenko, V. G.; Balenkova, E. S.
Synthesis 2001, 2081. (e) Korotchenko, V. N.; Shastin, A.
V.; Nenajdenko, V. G.; Balenkova, E. S. J. Chem. Soc.,
Perkin Trans. 1 2002, 883. (f) Nenajdenko, V. G.; Shastin,
A. V.; Korotchenko, V. N.; Varseev, G. N.; Balenkova, E. S.
Eur. J. Org. Chem. 2003, 302. (g) Nenajdenko, V. G.;
Shastin, A. V.; Golubinskii, I. V.; Lenkova, O. N.;
Balenkova, E. S. Russ. Chem. Bull. 2004, 53, 228.
(h) Nenajdenko, V. G.; Lenkova, O. N.; Shastin, A. V.;
Balenkova, E. S. Synthesis 2004, 573.
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 185.9 (CHO), 152.1,
151.7, 141.0, 137.0, 123.7, 112.1, 170.7.
MS: m/z (%) = 167 (49), 166 (31), 133 (24), 102 (14), 78 (8), 29
(100).
Anal. Calcd for C8H6ClNO: C, 57.33; H, 3.61. Found: C, 56.99; H,
3.39.
2-Chloro-3-thien-2-ylacrylaldehyde (4l)
Yellow solid; mixture of Z/E isomers (10:1); Rf 0.22 (hexane–
CH2Cl2, 1:2); mp 51 °C.
IR (Nujol): 1695 (C=O), 1607 (C=C), 750 cm–1.
1H NMR (400 MHz, CDCl3): d (Z-isomer) = 9.48 (s, 1 H, CHO),
7.80 (s, 1 H, HC=), 7.73 (d, 1 H, J = 5.3 Hz), 7.62 (d, 1 H, J = 3.8
Hz), 7.21 (dd, 1 H, J = 5.3, 3.8 Hz).
(5) Rulev, A. Yu. Russ. Chem. Rev. (Russ. Transl.) 1998, 67,
317.
(6) Maerkl, G. Chem. Ber. 1962, 95, 3003.
(7) Dieter, R.; Nice, L.; Velu, S. Tetrahedron Lett. 1996, 37,
2377.
13C NMR (100 MHz, CDCl3): d (Z-isomer) = 185.3 (CHO), 138.1,
136.2, 135.5, 133.6, 127.7.
(8) Masure, D.; Chuit, C.; Sauvêtre, R.; Normant, J. F. Synthesis
1978, 458.
(9) (a) Kamigata, N.; Satoh, T.; Yoshida, M. Bull. Chem. Soc.
Jpn. 1988, 61, 449. (b) Ley, S. V.; Whittle, A. J.
Tetrahedron Lett. 1981, 3301.
MS: m/z (%) = 172 (100), 144 (39), 109 (73), 84 (55).
Anal. Calcd for C7H5ClOS: C, 48.70; H 2.92. Found: C, 48.52; H,
2.84.
(10) Satoh, T.; Kitoh, Y.; Onda, K.; Takano, K.; Yamakawa, K.
Tetrahedron 1994, 50, 4957.
(11) McElvain, S.; Curry, M. J. Am. Chem. Soc. 1948, 70, 3781.
Synthesis 2005, No. 4, 605–609 © Thieme Stuttgart · New York