An efficient simple one-pot synthesis, characterization and structural studies of some 1,2,3,5-tetraarylpentane-1,5-diones

Article abstract of DOI:10.1016/j.molstruc.2013.10.037

A series of 1,2,3,5-tetraarylpentane-1,5-diones (9-23) were synthesised by simple one-pot method and characterized by FT-IR, ¹H NMR, ¹³C NMR and mass spectral techniques. The structure of 3-(4-fluorophenyl)-1,2,5-triphenylpentane-1,5-dione (10) was determined by single crystal X-ray diffraction analysis. The compound 10 crystallize in monoclinic crystal system, in C2/c space group. The torsional angle between the two keto groups was found to be -29.50. The C(23)C(22)C(15)C(8)C(7) chain is almost planar with "W" conformation and observed maximum deviation is 0.122 ? for C(15) from the C(23)/C(22)/C(15)/C(8)/C(7) plane.

Full text of DOI:10.1016/j.molstruc.2013.10.037

Journal of Molecular Structure 1058 (2014) 1–8
Contents lists available at ScienceDirect
Journal of Molecular Structure
journal homepage: www.elsevier.com/locate/molstruc
An efficient simple one-pot synthesis, characterization and structural
studies of some 1,2,3,5-tetraarylpentane-1,5-diones
⇑
G. Senthilkumar, K. Neelakandan, H. Manikandan
Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu, India
h i g h l i g h t s
ꢀ
ꢀ
ꢀ
The main advantages are time saving, easy workup and high yield of product.
The one-pot method is economy and reduces the usage of solvent.
Single crystal X-ray diffraction analysis, FTIR, 1H NMR, 13C NMR and mass spectral techniques.
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 13 May 2013
Received in revised form 13 October 2013
Accepted 14 October 2013
Available online 23 October 2013
A series of 1,2,3,5-tetraarylpentane-1,5-diones (9–23) were synthesised by simple one-pot method and
characterized by FT-IR, 1H NMR, 13C NMR and mass spectral techniques. The structure of 3-(4-fluoro-
phenyl)-1,2,5-triphenylpentane-1,5-dione (10) was determined by single crystal X-ray diffraction analy-
sis. The compound 10 crystallize in monoclinic crystal system, in C2/c space group. The torsional angle
between the two keto groups was found to be À29.50°. The C(23)AC(22)AC(15)AC(8)AC(7) chain is
almost planar with ‘‘W’’ conformation and observed maximum deviation is 0.122 Å for C(15) from the
C(23)/C(22)/C(15)/C(8)/C(7) plane.
Keywords:
1,5-Diketones
Crystal structure
Monoclinic
Ó 2013 Elsevier B.V. All rights reserved.
Torsional angle
‘‘W’’ conformation
1. Introduction
heterocyclization of 1,5-diketones under acidic conditions yields
pyrans, pyrylium salts and di or tetrahydropyrans [11].
Multi component reactions (MCRs) continue to attract synthetic
organic chemist due to several merits. Significantly complex organ-
ic molecules can be synthesized from relatively simpler starting
materials in a single step. This makes them more economical and
green as compared with conventional multistep synthesis. MCRs
have been successfully used to synthesize different classes of com-
pounds or scaffolds [1]. Diketones are one of the important syn-
thetic intermediates and desirable starting materials for
synthesis of numerous heterocycles [2–4] and poly functional
compounds [5–8]. 1,5-Dicarbonyl compounds can be further trans-
formed into useful multifunctional molecules. The potential of 1,5-
diketones to yield heterocycles upon cyclization in presence of
nucleophiles makes them key intermediates for the synthesis of
various heterocyclic compounds. The reaction between 1,5-dike-
tones and hydrogen sulphide gives thiopyrans [9], whereas use of
ammonia and its derivatives result in synthesis of pyridine,
dihydropyridine, diazapine and pipridine [10] as product. The
The reactions of an alkanone with an aldehyde are one of the
most extensively applied reactions in synthetic organic chemistry.
The alkanone undergoes a two component bimolecular reaction
with the aldehyde to form an
hydroxy ketones [13]. Conjugate addition of active enolates and
other nucleophiles to ,b-unsaturated enones is an efficient
a,b-unsaturated ketone [12] or a b-
a
method of CAC bond formation and has wide application in organ-
ic synthesis [14]. According to the reports in literatures, there are
four procedures for synthesizing 1,5-diketones: (i) by the aldol–
Michael addition strategy [15–18]; (ii) the addition of activated
methylene compounds to
a,b-unsaturated ketones [19]; (iii) the
condensation of ketone enolate and the Mannich base derived from
methyl ketones [20]; and (iv) the conjugate addition of the enones
to trimethylsilylenol ethers as donor [21]. These methods can be
used for suitable reactive substrates, but there are some limita-
tions, such as the reaction between aldehyde and acetophenone
is only performed in alkaline alcohols and under refluxing condi-
tion. The aldehyde should have an electron withdrawing group
and needs a large amount of solvent. In addition, these methods
need to use more expensive reagents and have longer synthetic
⇑
Corresponding author. Tel.: +91 9976081307.
E-mail address: profmani.au@gmail.com (H. Manikandan).
0022-2860/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.molstruc.2013.10.037

2
G. Senthilkumar et al. / Journal of Molecular Structure 1058 (2014) 1–8
routes. The fourth method is considered to be a better one, but it
should be carried under moisture and oxygen-free conditions.
Considering the utility of the 1,5-diones and demerits in the
existing methods to synthesize them, there is a need to develop
protocols which would yield structurally complex 1,5-diones using
simpler and greener procedures. The present communication de-
scribes two such methods for synthesis of 1,5-diones, which to
an extent overcome demerits of the reported methods.
2.4.3. 1-(4-Methoxyphenyl)-2-phenylethanone (6)
Yield: 81%; MP: 73–75 °C; FT-IR (KBr, cmÀ1): 1686 (C@O),
3095–3057 (CAH), 2985–2862 (CAH); 1H NMR (CDCl3, 400 MHz,
ppm): d = 3.85 (s, 3H, OCH3), 4.22 (s, 2H, CH2), 6.91–8.00 (m,
9H); Mass (m/z): 249 [M + Na]+, 227 [M + 1]+ and 135.
2.4.4. 1,2,3,5-Tetraphenylpentane-1,5-dione 9
FT-IR (KBr, cmÀ1): 1686 (C@O), 3079–3028 (CAH), 2913–2849
(CAH); 1H NMR (CDCl3, 500 MHz, ppm): d = 5.51 (d, 1H, H-2),
4.20 (m, 1H, H-3), 3.48 (dd, 1H, H-4a), 2.78 (dd, 1H, H-4b), 7.62–
7.89 (m, 20H); 13C NMR (DMSO-d6, 400 MHz, ppm): d = 198.7 (C-
1, C-5), 58.6 (C-2), 44.6 (C-3), 42.8 (C-4), 126.5–142.5; Mass (m/
z): 427 [M + Na]+, 405 [M + 1]+ and 209.
2. Experimental
2.1. General
The purity and completion of reaction was monitored by TLC.
The melting points were recorded in open capillaries and are
uncorrected. The FT-IR spectra were recorded on a AVATAR-
330FT-IR spectrophotometer. The sample was mixed with KBr
2.4.5. 3-(4-Fluorophenyl)-1,2,5-triphenylpentane-1,5-dione 10
FT-IR (KBr, cmÀ1): 1671 (C@O), 3063–3026 (CAH), 2923–2851
(CAH); 1H NMR (CDCl3, 300 MHz, ppm): d = 5.11 (d, 1H, H-2),
4.37 (m, 1H, H-3), 3.18 (dd, 1H, H-4a), 3.06 (dd, 1H, H-4b), 6.85–
7.80 (m, 19H); 13C NMR (CDCl3, 125 MHz, ppm): d = 198.6 (C-1,
C-5), 58.6 (C-2), 44.6 (C-3), 42.8 (C-4), 126.5–142.5; Mass (m/z):
445 [M + Na]+, 423 [M + 1]+ and 227.
and pellet technique was adopted to record the spectra in cmÀ1
.
1H NMR spectra were recorded at 500 or 400 MHz on BRUKER
AV-III or Varian 400 MHz spectrometer using CDCl3 as solvent
and TMS as internal standard. 13C NMR spectra were recorded at
125 or 100 or 75 MHz on BRUKER AV-III spectrometer in CDCl3.
For recording 1H NMR spectra, solution were prepared by dissolv-
ing about 10 mg of the compound in 0.5 mL of CDCl3. While for
recording 13C NMR spectra, about 50 mg of the compound was dis-
solved in the same volume of the solvent. Mass spectra were re-
corded on SCIEX-API 2000.
2.4.6. 3-(4-Chlorophenyl)-1,2,5-triphenylpentane-1,5-dione 11
FT-IR (KBr, cmÀ1): 1682, 1671 (C@O), 3059–3019 (CAH), 2904
(CAH); 1H NMR (CDCl3, 500 MHz, ppm): d = 5.13 (d, 1H, H-2),
4.38 (m, 1H, H-3), 3.19 (dd, 1H, H-4a), 3.09 (dd, 1H, H-4b), 7.15–
7.83 (m, 19H); 13C NMR (CDCl3, 125 MHz, ppm): d = 198.4 (C-1),
198.3 (C-5), 58.5 (C-2), 43.9 (C-3), 42.6 (C-4), 127.9–132.9.
2.2. General procedure for preparing 2-phenylacetophenone (4,5 & 6)
2.4.7. 3-(4-Bromophenyl)-1,2,5-triphenylpentane-1,5-dione 12
FT-IR (KBr, cmÀ1): 1659 (C@O), 3079–3061 (CAH), 2996–2836
(CAH); 1H NMR(CDCl3, 500 MHz, ppm): d = 5.13 (d, 1H, H-2),
4.37 (m, 1H, H-3), 3.19 (dd, 1H, H-4a), 3.09 (dd, 1H, H-4b), 7.25–
7.83 (m, 19H); 13C NMR (CDCl3, 125 MHz, ppm): d = 198.3 (C-1,
C-5), 58.4 (C-2), 44.0 (C-3), 42.5 (C-4), 120.4–141.7.Mass (m/z):
507 [(M + 2)+Na]+, 505 [M + Na]+, 485 [M + 1]+, 289 and 287.
Benzyl phenyl ketone was prepared by Friedel Craft reaction. To
a solution of phenyl acetic acid (0.01 mol) in chloroform (25 mL),
thionyl chloride 97.3 mL, (0.01 mol) was added. This was refluxed
on a water bath for 30 min. Finely powdered anhydrous aluminium
chloride, (0.01 mol) was added in small portions to a mixture of
acid chloride and electron rich arenes (0.01 mol) at 0 °C. The mix-
ture was stirred for 1 h at 0 °C and poured over chopped ice. It was
extracted with chloroform and dried over anhydrous sodium sul-
phate. Removal of solvent by distillation gave the desired product
in 75–81% yield.
2.4.8. 3-(4-Methoxyphenyl)-1,2,5-triphenylpentane-1,5-dione 13
FT-IR (KBr, cmÀ1): 1677 (C@O), 3060–3019 (CAH), 2964–2827
(CAH); 1H NMR(CDCl3, 400 MHz, ppm): d = 4.96 (d, 1H, H-2),
4.20 (m, 1H, H-3), 3.49 (dd, 1H, H-4a), 3.37 (dd, 1H, H-4b),
3.65(s,3H, OCH3), 6.53–8.02 (m, 19H); 13C NMR (CDCl3, 75 MHz,
ppm): d = 199.6 (C-1), 198.7 (C-5), 59.5 (C-2), 45.0 (C-3), 43.6 (C-
4), 54.9 (OCH3), 113.4–157.8; Mass (m/z): 457 [M + Na]+, 435
[M + 1]+ and 239.
2.3. General procedure for preparing 1,2,3,5-tetraphenylpentan-1,5-
diones (9–23)
A mixture of 2-phenylacetophenone (4/5/6) (0.01 mol), ace-
tophenones (7) (0.01 mol), bezaldehydes (8) (0.01 mol) and so-
dium hydroxide solution (10 mL, 10%) in ethanol (50 mL) was
stirred for 60 min at room temperature. The solid that separated
was filtered and was recrystallized from ethanol.
2.4.9. 3-(3-Methoxyphenyl)-1,2,5-triphenylpentane-1,5-dione 14
FT-IR (KBr, cmÀ1): 1681 (C@O), 3059–3003 (CAH), 2964–2842
(CAH); 1H NMR (CDCl3, 400 MHz, ppm): d = 5.15 (d, 1H, H-2),
4.36 (m, 1H, H-3), 3.83 (dd, 1H, H-4a), 3.07 (dd, 1H, H-4b), 3.68
(s, 3H, OCH3), 6.59–7.81 (m, 19H); 13C NMR (CDCl3, 125 MHz,
ppm): d = 198.7 (C-1), 198.6(C-5), 58.5 (C-2), 44.7 (C-3), 42.9 (C-
4), 55.1(OCH3), 112.0–159.4; Mass (m/z): 457 [M + Na]+, 435
[M + 1]+ and 239.
2.4. Spectral data of synthesized compounds
2.4.1. 1,2-Diphenylethanone (4)
Yield: 75%; MP: 55–57 °C; FT-IR (KBr, cmÀ1): 1684 (C@O),
3084–3031 (CAH), 2902–2805 (CAH); 1H NMR (CDCl3, 400 MHz,
ppm): d = 4.28 (s, 2H, CH2), 6.99–8.10 (m, 10H); Mass (m/z): 219
[M + Na]+, 197 [M + 1]+ and 105.
2.4.10. 1,2,5-Triphenyl-3-(3,4,5-trimethoxyphenyl)pentane-1,5-dione
15
FT-IR (KBr, cmÀ1): 1679 (C@O), 3059–3030 (CAH), 2997–2835
(CAH); 1H NMR(CDCl3, 300 MHz, ppm): d = 5.19 (d, 1H, H-2),
3.12 (dd, 1H, H-4b), 3.70 (s, 3H, OCH3), 3.68 (s, 6H, OCH3), 6.46–
8.03 (m, 17H); 13C NMR (CDCl3, 75 MHz, ppm): d = 198.7 (C-1),
198.6(C-5), 58.5 (C-2), 44.7 (C-3), 42.9 (C-4), 55.1(OCH3), 112.0–
159.4; Mass (m/z): 517 [M + Na]+, 495 [M + 1]+, 477 and 299.
2.4.2. 2-phenyl-1-p-tolylethanone (5)
Yield: 79%; MP:104–106 °C; FT-IR (KBr, cmÀ1): 1691 (C@O),
3064–3042 (CAH), 2952–2131 (CAH); 1H NMR (CDCl3, 400 MHz,
ppm): d = 2.39 (s, 3H, CH3), 4.25 (s, 2H, CH2), 7.21–7.92 (m, 9H);
Mass (m/z): 233 [M + Na]+, 211 [M + 1]+ and 119.

G. Senthilkumar et al. / Journal of Molecular Structure 1058 (2014) 1–8
3
O
C
AlCl3
SOCl2
CH2 COOH
CH2 COCl
CH2
R
4=R=H
5=R=CH3
6=R=OCH3
R
Scheme 1. Synthetic route for 2-phenylacetophenone.
R1
O
R4
C
CH3
OHC
R2
NaOH EtOH
R3
R1
O
O
C
CH2
C
R
R4
CH CH
R2
R3
NaOH
EtOH
R2
R1
R3
O
O
R
C
CH CH CH2 C
R4
Scheme 2. Double step synthesis of 1,2,3,5-tetraphenylpentane-1,5-diones.
R2
O
R1
R3
CH2
C
R
4 or 5 or 6
EtOH
O
C
O
R1
R
CH CH CH2
C
R4
NaOH
O
C
CHO
R2
R4
CH3
9 - 23
7
8
R3
Scheme 3. One-pot synthesis of 1,2,3,5-tetraphenylpentane-1,5-diones.
2.4.11. 1,2,5-Triphenyl-3-p-tolylpentane-1,5-dione 16
(CH3), 127.7–139.4; Mass (m/z): 441 [M + Na]+, 419 [M + 1]+ and
223.
FT-IR (KBr, cmÀ1): 1673 (C@O), 3057–3027 (CAH), 2923–2855
(CAH); 1H NMR(CDCl3, 300 MHz, ppm): d = 5.15 (d, 1H, H-2),
4.35 (m, 1H, H-3), 3.17 (dd, 1H, H-4a), 3.05 (dd, 1H, H-4b), 2.18
(s,3H, CH3), 6.96–7.81 (m, 19H); 13C NMR (CDCl3, 75 MHz, ppm):
d = 198.8 (C-1), 198.6 (C-5), 58.6 (C-2), 44.1 (C-3), 43.0 (C-4), 20.9
2.4.12. 3-(3-Nitrophenyl)-1,2,5-triphenylpentane-1,5-dione 17
FT-IR (KBr, cmÀ1): 1678 (C@O), 3063–3024 (CAH), 2923–2853
(CAH); 1H NMR (CDCl3, 300 MHz, ppm): d = 5.15 (d, 1H, H-2),

4
G. Senthilkumar et al. / Journal of Molecular Structure 1058 (2014) 1–8
Table 1
Analytical data for compounds 9–23.
Entry
R
R1
R2
R3
R4
Yield (%)
M.P. (°C)
m/z [M + Na]+
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
H
H
H
H
H
H
H
H
H
H
H
H
H
F
Cl
Br
OCH3
H
OCH3
CH3
H
H
OCH3
H
H
H
H
H
H
H
OCH3
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
F
93
95
96
92
97
96
93
92
94
96
95
93
94
96
97
184–186
201–203
194–196
188–190
141–143
173–175
100–102
154–156
188–190
168–170
136–138
182–184
168–170
182–184
158–160
427
445
–
507
457
457
517
441
472
441
487
457
459
463
495
H
OCH3
OCH3
H
NO2
H
H
H
H
H
H
CH3
OCH3
OCH3
CH3
H
F
F
Cl
H
H
Cl
Table 2
Table 4
Coupling constants of 1,2,3,5-tetraarylpentane-1,-5-diones (Hz).
1H chemical shifts of 1,2,3,5-tetraarylpentane-1,-5-diones (ppm).
Entry
H-2
H-3
H-4
H4a
Aromatic
Others
Entry
H-2
J2,3
H-3
J3,4
H-4a
J2,3
H-4b
H4b
J3,2
J2,3
J2,3
J2,3
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
5.51
5.11
5.13
5.13
4.96
5.15
5.19
5.15
5.17
5.17
5.06
5.11
5.08
5.02
5.08
4.20
4.37
4.38
4.37
4.20
3.48
3.18
3.19
3.19
3.49
2.78
3.06
3.09
3.09
3.37
3.07
3.12
3.05
3.12
3.10
3.06
3.08
3.06
2.96
3.03
7.62–7.89
6.85–7.80
7.15–7.83
7.25–7.83
6.53–8.02
6.59–7.81
6.46–8.03
6.96–7.81
6.96–7.81
7.05–7.74
6.68–7.83
6.77–8.00
6.81–7.72
6.76–7.72
7.13–7.97
–
–
–
–
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
11.28
10.80
11.00
10.50
10.20
10.76
10.80
11.10
10.80
10.50
10.75
10.75
10.83
10.80
10.40
3.61
3.90
3.00
3.00
3.90
10.87
10.50
10.50
10.50
10.00
10.25
10.20
16.47
16.50
16.50
16.50
15.61
3.66
3.90
3.50
3.00
3.90
16.43
16.81
16.50
17.00
15.61
11.0
a
OCH3-3.65
OCH3-3.68
OCH3-3.70, 3.68
CH3-2.18
–
CH3-2.32
OCH3-3.65
OCH3-3.77
CH3-3.65
–
10.05
4.36
3.83
3.85
10.23
9.74
16.23
3.87
16.19
a
a
a
a
a
a
a
a
4.35
4.50
4.41
4.32
4.37
4.35
4.28
4.32
3.17
3.29
3.21
3.13
3.17
3.16
3.06
3.12
3.70
3.30
3.50
3.92
3.92
3.84
10.35
10.50
10.25
10.31
10.27
10.35
9.90
15.91
17.70
16.00
16.07
17.39
16.31
3.70
3.45
3.50
3.95
3.91
3.84
10.35
17.11
16.51
16.03
16.19
16.31
10.05
10.00
9.91
9.83
10.03
2.80
10.40
10.40
16.40
3.20
16.40
a
a
a
a
a
a
–
a
a
Peaks merged.
Peaks merged.
Table 3
13C chemical shifts of 1,2,3,5-tetraarylpentane-1,-5-diones (ppm).
4.41 (m, 1H, H-3), 3.21 (dd, 1H, H-4a), 3.10 (dd, 1H, H-4b), 2.32
(s,3H, CH3), 7.05–7.74 (m, 19H); 13C NMR (CDCl3, 125 MHz,
ppm): d = 198.8 (C-1), 198.2 (C-5), 58.4 (C-2), 44.6 (C-3), 42.9
Entry C-1 C-5 C-2 C-3 C-4 Aromatic
Others
9
10
11
12
13
14
15
198.7 198.7 58.6
198.6 198.6 58.8
198.4 198.3 58.5
198.3 198.3 58.4
199.6 198.7 59.5
198.7 199.6 58.5
199.0 199.0 58.0
44.6 42.8 126.5–142.5
44.0 42.8 115.1–161.4
43.9 42.6 127.9–132.9
44.0 42.5 120.4–141.7
45.0 43.6 113.4–157.8 OCH3-54.9
44.7 42.9 112.0–159.4 OCH3-55.1
45.2 42.8 127.9–152.8 OCH3-
56.0,60.7
–
–
–
–
R1
R2
16
17
18
19
198.8 198.6 58.6
197.8 197.7 58.2
198.8 198.2 58.4
44.1 43.0 127.7–139.4 CH3-20.9
O
R3
43.8 42.2 121.7–148.1
–
44.6 42.9 126.5–143.5 CH3-21.5
R
C
199.1 197.2 58.35 43.9 43.1 163.3–113.6 OCH3-
55.4,55.1
44.6 43.0 163.3–113.6 OCH3-55.4
43.9 42.8 162.5–115.0 CH3-21.6
1
20
21
22
23
198.9 197.0 58.1
198.7 198.1 58.5
198.5 197.0 58.7
198.2 197.2 58.5
CH CH
2
O
3
4
44.0 42.7 115.1–166.9
43.9 42.6 121.9–143.9
–
–
C
C
5
Ha
Hb
4.50 (m, 1H, H-3), 3.29 (dd,1H, H-4a), 3.12 (dd, 1H, H-4b), 6.96–
7.81 (m, 19H); 13C NMR (CDCl3, 75 MHz, ppm): d = 197.8 (C-1),
197.7 (C-5), 58.2 (C-2), 43.8 (C-3), 42.2 (C-4), 121.7–148.1; Mass
(m/z): 472 [M + Na]+, 450 [M + 1]+, 254 and 197.
2.4.13. 2,3,5-Triphenyl-1-p-tolylpentane-1,5-dione 18
R4
FT-IR (KBr, cmÀ1): 1682, 1671 (C@O), 3073–3028 (CAH), 2922–
2849 (CAH); 1H NMR(CDCl3, 500 MHz, ppm): d = 5.17 (d, 1H, H-2),
Fig. 1. Representative structure of compound.

G. Senthilkumar et al. / Journal of Molecular Structure 1058 (2014) 1–8
5
Fig. 2. ORTEP of compound 10.
(C-4), 21.5 (CH3), 126.5–143.5; Mass (m/z): 441 [M + Na]+, 419
2.4.15. 1-(4-Methoxyphenyl)-2,3,5-triphenylpentane-1,5-dione 20
[M + 1]+ and 209.
FT-IR (KBr, cmÀ1): 1684, 1664 (C@O), 3059–3029 (CAH), 2961–
2838 (CAH); 1H NMR (CDCl3, 400 MHz, ppm): d = 5.11 (d, 1H, H-2),
4.37 (m, 1H, H-3), 3.17 (dd, 1H, H-4a), 3.08 (dd, 1H, H-4b), 3.77 (s,
3H, OCH3), 6.77–8.00 (m, 19H); 13C NMR (CDCl3, 100 MHz, ppm):
d = 198.9 (C-1), 197.0 (C-5), 58.1 (C-2), 44.6 (C-3), 43.0 (C-4), 55.4
(OCH3), 113.6–163.3; Mass (m/z): 457 [M + Na]+, 435 [M + 1]+,
227, 209 and 174.
2.4.14. 1,3-Bis(4-methoxyphenyl)-2,5-diphenylpentane-1,5-dione 19
FT-IR (KBr, cmÀ1): 1682, 1668 (C@O), 3052 (CAH), 2928–2839
(CAH); 1H NMR (CDCl3, 400 MHz, ppm): d = 5.06 (d, 1H, H-2),
4.32 (m, 1H, H-3), 3.13 (dd, 1H, H-4a), 3.05 (dd, 1H, H-4b), 3.67
(s, 3H, OCH3), 3.77 (s, 3H, OCH3), 6.68–7.83 (m, 18H); 13C NMR
(CDCl3, 100 MHz, ppm): d = 199.1 (C-1), 197.2 (C-5), 58.4 (C-2),
43.9 (C-3), 43.1(C-4), 55.4 (OCH3), 55.1 (OCH3), 113.6–1633; Mass
(m/z): 487 [M + Na]+, 465 [M + 1]+, 301 and 239.
2.4.16. 3-(4-Fluorophenyl)-2,5-diphenyl-1-p-tolylpentane-1,5-dione
21
FT-IR (KBr, cmÀ1): 1685, 1669 (C@O), 3058–3030 (CAH), 2921–
2851 (CAH); 1H NMR(CDCl3, 400 MHz, ppm): d = 5.08 (d, 1H, H-2),
Table 5
Crystal data and structure refinement detail for10.
Compound
10
Empirical formula
Formula weight
Temperature
Wavelength
Crystal system, space group
Unit cell dimensions
C
29H23FO2
422.47
293(2) K
0.71073 Å
Monoclinic, C2/c
a = 40.405(4) Å
a = 90°
b = 5.9216(6) Å b = 93.909°(12)
c = 18.431(12) Å
4399.5(8) Å3
8, 1.276 mg/m3
0.105 mmÀ1
1776
c = 90°
Volume
Z, Calculated density
Absorption coefficient
F(000)
Crystal size
Theta range for data collection
Limiting indices
Reflections collected/unique
Completeness to theta = 30.87
Absorption correction
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R, Rw (obs, data)
0.25 Â 0.23 Â 0.20 mm
2.02–28.60°
À53 6 h 6 54, À7 6 k 6 7, À24 6 l 6 24
36473/5536[R(int) = 0.09191]
99.9%
Multi-scan
Full-matrix least-squares on F2
5539/0/289
1.059
0.0781, 0.1360
Fig. 3. Packing diagram of compound 10.

6
G. Senthilkumar et al. / Journal of Molecular Structure 1058 (2014) 1–8
4.35 (m, 1H, H-3), 3.16 (dd, 1H, H-4a), 3.06 (dd, 1H, H-4b), 2730 (s,
3H, CH3), 6.81–7.72 (m, 18H); 13C NMR (CDCl3, 100 MHz, ppm):
d = 198.7 (C-1), 198.1 (C-5), 58.5 (C-2), 43.9 (C-3), 42.8 (C-4), 21.6
(CH3), 115.0–162.5; Mass (m/z): 459 [M + Na]+, 437 [M + 1]+ and
227.
difference syntheses (SHELXS-97) and refined by full matrix least
square procedure on F2 with anisotropic thermal parameters. All
non hydrogen atoms were refined (SHELXL-97) and placed at
chemically acceptable position. A total of 289 parameters were re-
fined with 5539 unique reflections which covered the residuals to
R1 = 0.0781. Crystallographic data have been deposited with the
Cambridge Crystallographic Data Centre as supplementary
publications number CCDC 853753 for 10. Copies of the data can
be obtained free of charge via http://www.ccdc.cam.ac.uk/conts/
retrieving.html, or from the Cambridge Crystallographic Data
Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: (+44) 1223
336 033: or e-mail: deposit@ccdc.cam.ac.uk (see Scheme 1).
2.4.17. 3,5-Bis(4-fluorophenyl)-1,2-diphenylpentane-1,5-dione 22
FT-IR (KBr, cmÀ1): 1677 (C@O), 3061–3024 (CAH), 2933–2904
(CAH); 1H NMR(CDCl3, 400 MHz, ppm): d = 5.02 (d, 1H, H-2),
4.28 (m, 1H, H-3), 3.06 (dd, 1H, H-4a), 2.96 (dd, 1H, H-4b), 6.76–
7.72 (m, 18H); 13C NMR (CDCl3, 100 MHz, ppm): d = 198.5 (C-1),
197.0 (C-5), 58.7 (C-2), 43.7 (C-3), 42.7 (C-4), 115.1–166.9; Mass
(m/z): 463 [M + Na]+, 441 [M + 1]+ and 245.
3. Results and discussion
2.4.18. 3,5-Bis(4-chlorophenyl)-1,2-diphenylpentane-1,5-dione 23
FT-IR (KBr, cmÀ1): 1684, 1660 (C@O), 3057–3019 (CAH), 2924–
2843 (CAH); 1H NMR(CDCl3, 400 MHz, ppm): d = 5.08 (d, 1H, H-2),
4.32 (m, 1H, H-3), 3.12 (dd, 1H, H-4a), 3.03 (dd, 1H, H-4b), 7.13–
7.97 (m, 18H); 13C NMR (CDCl3, 100 MHz, ppm): d = 198.2 (C-1),
197.2 (C-5), 58.5 (C-2), 43.9 (C-3), 42.6 (C-4), 121.9–143.9; Mass
(m/z): 495 [M + Na]+, 473 [M + 1]+ and 277.
The 1,2,3,5-tetraarylpentane-1,5-diones were prepared in two
steps. The aryl aldehydes were subjected to Claisen–Schmidt reac-
tion with acetophenone to give corresponding a,b-unsaturated ke-
tones (chalcones). The chalcones were then subjected to Michael
addition with 2-aryl acetophenone to yield the 1,2,3,5-tetraaryl-
pentane-1,5-diones. Sodium hydroxide was used as catalyst and
the process avoids the use of hazardous chemicals and harsh con-
2.5. X-ray data collection, structure solution and refinement
Table 7
Selected bond Angles [°] for 10.
Crystal was grown by slow evaporation technique using ace-
tone as solvent. Determination of the unit cell and data collection
were performed on a (Bruker, 2008) APEX2 diffractometer using
Atoms
Angles
C(27)AC(26)AC(25)
C(9)AC(8)AC(7)
120.6(4)
108.01(18)
113.3(2)
110.73(19)
113.2(2)
110.3(2)
109.27(19)
117.3(2)
121.0(3)
122.2(3)
120.7(3)
119.0(3)
121.2(2)
121.5(3)
117.3(2)
120.5(3)
120.4(3)
120.3(3)
119.3(4)
120.8(3)
119.7(4)
121.5(2)
121.2(2)
120.3(2)
119.2(2)
120.4(2)
117.6(2)
121.3(2)
121.1(2)
116.1(2)
121.2(2)
118.5(3)
122.7(2)
118.7(3)
119.6(3)
118.5(3)
121.9(3)
118.5(2)
118.4(3)
122.8(2)
118.9(3)
120.6(3)
119.6(3)
120.4(3)
121.0(3)
120.1(3)
120.3(4)
graphite-monochromated M0
Ka radiation (k = 0.71073 Å) at
C(9)AC(8)AC(15)
C(7)AC(8)AC(15)
C(16)AC(15)AC(22)
C(16)AC(15)AC(8)
C(22)AC(15)AC(8)
C(17)AC(16)AC(21)
C(13)AC(14)AC(9)
C(18)AC(17)AC(16)
C(11)AC(10)AC(9)
C(19)AC(20)AC(21)
O(2)AC(23)AC(24)
O(2)AC(23)AC(22)
C(24)AC(23)AC(22)
C(12)AC(13)AC(14)
C(2)AC(1)AC(6)
293 K with crystal size of 0.25 Â 0.20 Â 0.20 mm. Multi-scan
absorption correction were applied using the SADABAS program.
The structure was solved by direct methods and successive Fourier
Table 6
Selected bond lengths [Å] for 10.
Atoms
Distance
C(1)AC(2)
C(3)AC(2)
C(3)AC(4)
C(5)AC(4)
C(6)AC(1)
C(6)AC(5)
C(7)AC(6)
C(7)AO(1)
1.369(5)
1.374(6)
1.365(6)
1.373(4)
1.397(4)
1.389(4)
1.480(4)
1.221(3)
1.530(3)
1.514(3)
1.559(3)
1.387(4)
1.394(3)
1.381(4)
1.368(5)
1.365(5)
1.374(4)
1.510(3)
1.31(4)
1.384(3)
1.394(3)
1.373(4)
1.362(4)
1.370(4)
1.372(4)
1.508(3)
1.502(4)
1.210(3)
1.379(5)
1.392(4)
1.385(5)
1.359(6)
1.369(6)
1.389(6)
1.353(3)
C(4)AC(5)AC(6)
C(26)AC(27)AC(28)
C(24)AC(25)AC(26)
C(28)AC(29)AC(24)
C(17)AC(16)AC(15)
C(21)AC(16)AC(15)
O(1)AC(7)AC(6)
C(8)AC(7)
C(8)AC(9)
C(8)AC(15)
C(9)AC(10)
C(9)AC(14)
C(10)AC(11)
C(11)AC(12)
C(13)AC(12)
C(14)AC(13)
C(15)AC(16)
C(15)AC(22)
C(16)AC(17)
C(16)AC(21)
C(17)AC(18)
C(19)AC(18)
C(20)AC(19)
C(21)AC(20)
C(22)AC(23)
C(23)AC(24)
C(23)AO(2)
C(24)AC(25)
C(24)AC(29)
C(26)AC(25)
C(26)AC(27)
C(27)AC(28)
C(29)AC(28)
F(1)AC(19)
O(1)AC(7)AC(8)
C(7)AC(6)AC(8)
C(10)AC(9)AC(14)
C(10)AC(9)AC(8)
C(14)AC(9)AC(8)
C(23)AC(22)AC(15)
C(20)AC(21)AC(16)
C(5)AC(6)AC(1)
C(5)AC(6)AC(7)
C(1)AC(6)AC(7)
F(1)AC(19)AC(18))
F(1)AC(19)AC(20))
C(18)AC(19)AC(20)
C(19)AC(18)AC(17)
C(25)AC(24)AC(29)
C(25)AC(24)AC(23)
C(29)AC(24)AC(23)
C(12)AC(11)AC(10)
C(13)AC(12)AC(11)
C(4)AC(3)AC(2)
C(27)AC(28)AC(29)
C(1)AC(2)AC(3)
C(3)AC(4)AC(5)

G. Senthilkumar et al. / Journal of Molecular Structure 1058 (2014) 1–8
7
dition like heating. After having success in the synthesis of 1,5-
diones using relatively moderate conditions in two steps (Scheme
2), we pondered whether we can make this protocol even more
attractive by carrying out the synthesis in a one-step multi compo-
nent reaction. This would avoid isolation of chalcones, decrease No.
of operations and would in essence be easy to execute and more
green in terms of solvent usage etc. An experiment was designed
and executed wherein equi-molar mixture of 2-phenylacetophe-
none, acetophenone, benzaldehyde and sodium hydroxide solution
in ethanol was stirred at room temperature. To our gratification
reaction worked well to yield corresponding 1,2,3,5-tetraarylpen-
tane-1,5-dione (Scheme 3). After having success with one of the
substrates, the reactions were carried out using all other substrates
and were found to be successful.
[M + 1]+ is consistent with proposed molecular formula of the
compound. The other prominent peak is observed at m/z 209 (see
Tables 1–3).
3.3. NMR spectral analysis of compound 9
3.3.1. 1H NMR
The 1H NMR showed a doublet observed at 5.51 ppm, corre-
sponding to one proton is assigned to H-2. A multiplet centred at
4.20 ppm due to H-3. The compounds also exhibited the presence
of two magnetically non-equivalent protons of a methelene group
(Ha/Hb at C-4), at 3.48 ppm and 2.78 ppm, respectively, coupled
with each other and inturn with vicinal methane proton H-3 and
produce two double doublets. The coupling constant values are gi-
ven in Table 4. The aromatic protons appear in the range 6.46–
8.03 ppm.
Here, we have disclosed an efficient, simple one-pot process for
the synthesis of 1,2,3,5-tetraphenylpentan-1,5-diones, wherein so-
dium hydroxide is used as catalyst and the process avoids the use
of hazardous chemicals and harsh condition like heating. An over-
all yield of 95% is claimed for this one-pot synthetic procedure.
3.3.2. 13C NMR
The 13C NMR showed weak signals at around 198 ppm, due to
carbonyl carbons at C-1 and C-5. The chemical shifts of aromatic
carbon appear in the range 112.0–161.4 ppm. The signal observed
at 58.0–59.5 ppm corresponding to C-2. The signal appeared at
43.0–45.2 ppm is assigned to C-3. The signal observed at 42.2–
43.6 ppm is due to C-4 (see Fig. 1).
3.1. IR spectral analysis of compound 9
In IR spectra, the presence of carbonyl stretching frequency
around 1686 cmÀ1 confirms the diketone formation. A collection
of bands observed in the region of 3079–3028 cmÀ1 are due to aro-
matic CAH stretching frequency. The absorption bands appeared in
the region of 2913–2849 cmÀ1 is assigned to aliphatic CAH stretch-
ing frequencies. The C@C stretching frequency observed at
3.4. X-ray structure determination of 3-(4-fluorophenyl)-1,2,5-
triphenylpentane-1,5-dione(10)
1597 cmÀ1
.
The single crystal X-ray structural analysis reveals the structure
and geometry of 10 in the solid state. The compound 10 crystallizes
in a monoclinic system with C2/c space group. The ORTEP (Oak
Ridge Thermal Ellipsoids Plot) of the compound is shown in
Fig. 2 and the packing diagram is given in Fig. 3. Crystal data, data
collection parameters, selected bond distances and angles are gi-
ven in Tables 5–9.
3.2. Mass spectral analysis of compound 9
The mass spectrum of the compound yields a peak at m/z 427
which corresponds to [M + Na]+. The peak absorbed at m/z 405
Table 8
Atomic coordinates and equivalent isotopic displacement parameters for compound
10.
Table 9
Anisotropic displacement parameters for compound 10.
Atom
x
y
z
U(eq)
U11
72(2)
U22
49(2)
U33
81(2)
U23
U13
23(2)
U12
10(2)
À16(2)
À3(2)
8(2)
À2(1)
À18(1)
1(1)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
343(1)
35(1)
À1402(5)
À1424(7)
369(8)
4472(2)
4114(2)
3684(3)
3610(2)
3971(2)
4405(1)
4785(1)
4802(1)
4127(1)
3960(2)
3353(2)
2904(2)
3054(2)
3658(1)
5522(1)
6169(1)
6673(1)
7261(1)
7345(1)
6865(2)
6279(1)
5488(1)
6091(1)
6056(2)
5512(2)
5512(3)
6037(3)
6580(2)
6592(2)
5058(1)
6585(1)
7922(1)
67(1)
87(1)
101(1)
90(1)
63(1)
50(1)
47(1)
41(1)
41(1)
55(1)
68(1)
67(1)
61(1)
51(1)
45(1)
44(1)
53(1)
61(1)
57(1)
58(1)
51(1)
50(1)
54(1)
57(1)
75(1)
99(1)
103(1)
92(1)
79(1)
67(1)
77(1)
91(1)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
À16(2)
À38(2)
À35(3)
À8(2)
À2(1)
À9(1)
3(1)
3(1)
0(1)
2(1)
À12(2)
À3(2)
12(1)
7(1)
4(1)
4(1)
64(2)
63(2)
78(2)
63(2)
57(2)
64(2)
53(1)
50(1)
65(2)
68(2)
65(2)
71(2)
66(2)
55(1)
59(2)
78(2)
89(2)
67(2)
67(2)
64(2)
53(2)
53(2)
46(1)
61(2)
75(2)
69(2)
55(2)
58(2)
89(1)
77(1)
110(2)
73(2)
94(3)
74(2)
50(2)
40(1)
36(1)
32(1)
36(1)
46(2)
68(2)
87(2)
65(2)
41(1)
40(1)
36(1)
38(1)
48(2)
63(2)
50(2)
40(1)
54(2)
69(2)
69(2)
69(2)
71(2)
85(3)
117(3)
107(3)
39(1)
96(2)
99(2)
127(3)
141(4)
115(3)
76(2)
53(1)
42(1)
40(1)
37(1)
55(2)
70(2)
51(2)
48(2)
46(1)
39(1)
35(1)
43(1)
44(1)
44(1)
58(2)
49(1)
41(1)
41(1)
56(2)
94(2)
150(4)
153(4)
101(3)
70(2)
73(1)
56(1)
70(1)
17(2)
À21(2)
À29(2)
À8(2)
10(1)
10(1)
1(1)
À68(1)
135(1)
443(1)
554(1)
888(1)
2185(7)
2247(5)
446(4)
381(4)
1111(1)
1304(1)
1497(1)
1679(1)
1673(1)
1482(1)
1300(1)
1337(1)
1128(1)
1127(1)
936(1)
2471(4)
2442(4)
598(5)
2(1)
C(9)
C(9)
À1(1)
À2(1)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(27)
C(28)
C(29)
O(1)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(27)
C(28)
C(29)
O(1)
5(1)
7(1)
620(6)
13(2)
14(1)
5(1)
10(2)
À15(2)
À14(2)
À1(1)
4(1)
1(1)
1(1)
À14(2)
À18(2)
5(1)
2462(6)
4282(5)
4291(4)
2558(4)
2675(4)
941(4)
2(1)
À2(1)
0(1)
6(1)
9(1)
À2(1)
1(1)
14(1)
10(1)
6(1)
0(1)
2(1)
3(1)
À7(2)
À4(2)
À1(3)
À9(2)
À4(2)
À4(1)
À10(1)
41(1)
1015(5)
2859(5)
4629(5)
4529(4)
4530(5)
4641(5)
6503(5)
8107(6)
9832(7)
9943(8)
8362(8)
6619(7)
À1374(3)
3292(4)
2980(4)
741(1)
733(1)
924(1)
À4(1)
0(1)
8(1)
1(1)
2(1)
1581(1)
1852(1)
2103(1)
2088(1)
2320(1)
2572(1)
2591(1)
2362(1)
996(1)
À1(1)
À8(1)
À20(1)
À5(2)
À4(2)
À34(3)
À50(3)
À25(2)
17(1)
12(1)
À3(1)
8(1)
5(2)
À6(2)
À14(2)
À12(2)
À3(2)
4(2)
À3(1)
O(2)
F(1)
1867(1)
552(1)
O(2)
F(1)
4(1)
À18(1)

8
G. Senthilkumar et al. / Journal of Molecular Structure 1058 (2014) 1–8
Fig. 4. The ‘W’ conformation view.
Unit cell contains eight molecules with insignificant intermo-
Appendix A. Supplementary material
lecular interactions. From the ORTEP it is observed that the aryl
groups attached at C-8 and C-15 are exactly opposite to each other
[C(16)AC(15)AC(8)AC(9) = 177.79°]. The two keto group distances
are almost similar [C(7)AO(1) = 1.221 Å and C(23)AO(2) = 1.220 Å]
and the observed short distances indicate the double bonded nat-
ure of these bonds. The torsional angle between the two keto
groups was found to be À29.5°.
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.molstruc.2013.
10.037.
References
[1] Z.S. Arigan, H. Suschitiky, J. Chem. Soc. (1961) 2242.
[2] Z.S. Arigan, H. Suschitiky, J. Chem. Soc. (1961) 2242.
[3] S.S. Hirsch, W.J. Bailey, J. Org. Chem. 43 (1978) 4091.
[4] F. Krohnke, Synthesis (1976) 1.
[5] E.C. Constable, A.M.W. Cargill Thompson, J. Chem. Soc., Dalton Trans. (1992)
2947.
From the packing diagram it is observed that there are some
effective
Particularly, the
rings of two adjacent molecules (in chain) was found to be 3.52 Å as
shown in Fig. 3 ( ). The C(23)AC(22)AC(15)AC(8)AC(7) chain is
p–p
stacking interactions between the aryl groups.
p–p
stacking interaction between the terminal aryl
p–p
[6] K.T. Potts, Bull. Soc. Chem. Belg. 99 (1990) 741.
almost planar with ‘‘W’’ conformation (Fig. 4) and the observed
maximum deviation is 0.122 Å for C(15) from the C(23)/C(22)/
C(15)/C(8)/C(7) plane.
[7] I.R. Butler, S.J. Mcdonald, Polyhedron (1995) 529.
[8] N.S. Gill, K.B. James, F. Lions, K.T. Potts, J. Am. Chem. Soc. 74 (1952) 4923.
[9] N.T. Berberova, E.V. Shinkar, N.N. Letichevskaya, A.I. Fomenko, E.R. Milaeva,
E.N. Belevskii, A.I. Prokofev, Russ. J. Electrochem. 36 (2000) 203.
[10] V.G. Kharchenko, L.I. Markova, O.V. Fedotova, N.V. Pchelintseva, Chem.
Heterocycl. Compd. 39 (2003) 1121.
6. Conclusions
[11] V.G. Kharchenko, N.V. Pchelintseva, L.I. Markova, O.V. Fedotova, Chem.
Heterocycl. Compd. 36 (2000) 1007.
In conclusion, we have reported an efficient synthesis of 1,2,3,5-
tetraphenylpentan-1,5-diones by the three-component one pot
reactions of aromatic aldehydes, acetophenone and 2-phenylace-
tophenone catalysed by sodium hydroxide. This method is scalable
and has the advantages of easy work up, mild reaction conditions,
and high yields. Single crystal X-ray structural analysis of 10, has
also been performed and the results reveals that the torsional angle
between the two keto groups was found to be À29.5° and the
C(23)AC(22)AC(15)AC(8)AC(7) chain is almost planar with ‘‘W’’
conformation.
[12] R. Mestres, Green Chem. 6 (2004) 583.
[13] (a) D.B. Kimball, L.A. Silks III., Curr. Org. Chem. 10 (2006) 1975;
(b) C. Palomo, M. Oiarbide, J.M. Garcia, Chem. Soc. Rev. 33 (2004) 65.
[14] E.D. Bergmann, D. Ginsburg, R. Pappo, Org. React 10 (1959) 179.
[15] Z.S. Arigan, H. Suschitiky, J. Chem. Soc. (1961) 2242.
[16] S.S. Hirsch, W.J. Bailey, J. Org. Chem. 43 (1978) 4091.
[17] E.C. Constable, A.M.W. Cargill Thompson, J. Chem. Soc., Dalton Trans. (1992)
2947.
[18] K.T. Potts, Bull. Soc. Chem. Belg. 99 (1990) 741.
[19] F. Krohnke, Synthesis (1976) 1.
[20] N.S. Gill, K.B. James, F. Lions, K.T. Potts, J. Am. Chem. Soc. 74 (1952) 4923.
[21] V.M. Swamy, A. Sarka, Tetrahedron Lett. 39 (1998) 1261.
Acknowledgements
Authors like to acknowledge Annamalai University for neces-
sary facilities and Department of CAS in Crystallography and bio-
physics, University of Madras for recording single crystal XRD.