P2O5-hexamethyldisiloxane (HMDS): An efficient system to induce the three-component reaction of enolic systems, aromatic aldehydes, and acetonitrile

Article abstract of DOI:10.1080/00397910802213778

Three-component reaction of an enolizable compound, such as acetophenone, methyl acetoacetate, 4-hydroxycoumarin, 2-naphthol, or 3-hydroxy-2-naphthoic acid; an aromatic aldehyde, and acetonitrile induced by phosphorus pentoxide and hexamethyldisiloxane le

Full text of DOI:10.1080/00397910802213778

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P2O5-Hexamethyldisiloxane
(HMDS): An Efficient System to
Induce the Three-Component
Reaction of Enolic Systems,
Aromatic Aldehydes, and
Acetonitrile
Mohammad Anary-Abbasinejad a , Hossein Anaraki-
Ardakani a & Alireza Hassanabadi a
a Department of Chemistry, Islamic Azad University,
Yazd Branch, Yazd, Iran
Version of record first published: 14 Oct 2008.
To cite this article: Mohammad Anary-Abbasinejad, Hossein Anaraki-Ardakani &
Alireza Hassanabadi (2008): P2O5-Hexamethyldisiloxane (HMDS): An Efficient System
to Induce the Three-Component Reaction of Enolic Systems, Aromatic Aldehydes,
and Acetonitrile, Synthetic Communications: An International Journal for Rapid
Communication of Synthetic Organic Chemistry, 38:21, 3706-3716
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Synthetic Communications1, 38: 3706–3716, 2008
Copyright # Taylor & Francis Group, LLC
ISSN: 0039-7911 print=1532-2432 online
DOI: 10.1080/00397910802213778
P2O5-Hexamethyldisiloxane (HMDS): An
Efficient System to Induce the Three-Component
Reaction of Enolic Systems, Aromatic Aldehydes,
and Acetonitrile
Mohammad Anary-Abbasinejad, Hossein Anaraki-Ardakani, and
Alireza Hassanabadi
Department of Chemistry, Islamic Azad University, Yazd Branch,
Yazd, Iran
Abstract: Three-component reaction of an enolizable compound, such as aceto-
phenone, methyl acetoacetate, 4-hydroxycoumarin, 2-naphthol, or 3-hydroxy-2-
naphthoic acid; an aromatic aldehyde, and acetonitrile induced by phosphorus
pentoxide and hexamethyldisiloxane leads to 2-acetylamino ketones, methyl
3-(acetylamino aryl methyl)-3-oxobutanoates, 3-(acetylamino aryl methyl)-4-
hydroxycoumarins, 1-(acetylamino aryl methyl)-2-naphthols, or 4-(acetylamino
aryl methyl)-3-hydroxy-2-naphthoic acids in excellent yields.
Keywords: Aryl
2-naphthol, phosphorus pentoxide, three-component reaction
aldehydes,
hexamethyldisiloxane,
4-hydroxycoumarin,
Multicomponent reactions (MCRs) have received great attention from
chemists because they can be widely employed for the rapid assembly
of arrays with high molecular diversity.[1–5] The three-component reac-
tion of enolic systems such as aryl methyl ketones or b-dicarbonyl com-
pounds, aryl aldehydes, and acetonitrile has been recently used for the
synthesis of b-acetylamino ketones or esters. This reaction is usually car-
ried out in the presence of excess amounts of acetyl chloride as the oxygen
Received April 21, 2008.
Address correspondence to Mohammad Anary-Abbasinejad, Department of
Chemistry, Islamic Azad University, Yazd Branch, P. O. Box 89195-155, Yazd,
Iran. E-mail: mohammadanary@yahoo.com
3706

P2O5-Hexamethyldisiloxane
3707
activator and catalyzed by a Brønsted or Lewis acid. A number of catalysts
such as BiOCl,[6] ZrOCl2 ꢀ 8H2O,[7] CoCl2,[8] montmorillonite K-10 clay,[9]
H2SO4=SiO2,[10] heteropoly acids,[11] silica sulfuric acid,[12] NaHSO4-
SiO2,[13] and CsCl3 ꢀ 7H2O[14] have been employed to affect this transfor-
mation. The reaction of substituted acetophenones or b-ketoesters, aryl
aldehydes, and acetonitrile has also been carried out in the presence of an
excess amount of trimethylchlorosilane catalyzed by heteropoly acids.[15]
Very recently, we reported that a similar reaction can be carried out with
other enolic systems such as 4-hydroxycoumarin[16] or 2-naphthol,[17] aro-
matic aldehydes, and acetonitrile in the presence of chlorosulfonic acid.
The reaction between phosphorus pentoxide and hexamethyldisilox-
ane (HMDS) in organic solvents has been reported to produce a mixture
of silylated three- and tetraphosphates, known as polyphosphoric acid
trimethylsilylester (PPSE).[18] PPSE is a powerfull oxygen-activating
and dehydrating agent that has been used to promote different organic
processes such as dehydration of amides to nitriles,[19] pinacol rearrange-
ments,[20] synthesis of hetrocycles,[21] aldol-like condensations,[22] and
Friedel–Crafts[23] reactions. The employment of PPSE to promote the
organic transformations has been recently reviewed.[24]
In continuation of our work[16,17] on the three-component reaction of
enolic systems, aldehydes, and acetonitrile, here we report the results of
our investigation on the reaction of acetophenone, methyl acetoacetate,
4-hydroxycoumarin, 2-naphthol, or 3-hydroxy-2-naphthoic acid; aro-
matic aldehydes, and acetonitrile induced by a mixture of phosphorus
pentoxide and HMDS.
When a mixture of acetophenone and 4-chlorobenzaldehyde was stir-
red in acetonitrile in the presence of phosphorus pentoxide and HMDS, a
smooth reaction took place and was completed within 3 h (monitored by
thin-layer chromatography, TLC) (Scheme 1). After pouring the reaction
mixture into ice water, 3-acetylamino-3-(4-chlorophenyl) propiophenone
Scheme 1. Three-component reaction of aromatic aldehydes, acetophenones, and
acetonitrile promoted by P2O5=HMDS system.

3708
M. Anary-Abbasinejad, H. Anaraki-Ardakani, and A. Hassanabadi
Table 1. Optimization of the amounts of P2O5 and HMDS in the
reaction of acetophenone, 4-chlorobenzaldehyde, and acetonitrile
Entry
P2O5 (eq)
HMDS (eq)
Yield (%)
1
2
3
4
5
—
1
1
0.5
2
1
—
1
0.5
2
—
—
95
68
95
was obtained as a pale-yellow solid, which was pure on the basis of the
NMR data. As shown in Table 1, the best result was obtained by using 1
equivalent of phosphorus pentoxide and HMDS. No reaction was observed
in the absence of phosphorus pentoxide or HMDS. Increasing the amount
of phosphorus pentoxide or HMDS over 1 equivalent did not improve the
yield considerably. To investigate the scope of the reaction, different aceto-
phenones and aldehydes mixed together in acetonitrile in the presence of
phosphorus pentoxide and HMDS. The results are shown in Table 2. As
Table 2. Synthesis of b-acetylamino ketones, and esters by the reaction of aceto-
phenones, aromatic aldehydes or methyl acetoacetate, and acetonitrile in the pre-
sence of P2O5-HMDS system
Entry
Ar
R
Yield (%)a
Reference
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
C6H5
3-NO2C6H4
4-NO2C6H4
4-ClC6H4
2-ClC6H4
4-CH3OC6H4
C6H5
4-CH3C6H4
4-ClC6H4
C6H5
4-NO2C6H4
4-FC6H4
C6H5
4-ClC6H4
4-FC6H4
C6H5
C6H5
C6H5
C6H5
C6H5
C6H5
C6H5
95
97
88
95
92
89
94
89
93
82
87
85
82
89
89
76
84
15
15
13
15
13
15
15
15
15
12
12
12
12
15
12
15
15
4-NO2C6H4
4-NO2C6H4
4-NO2C6H4
4-MeC6H4
4-MeC6H4
4-MeC6H4
4-ClC6H4
4-ClC6H4
4-ClC6H4
CH3O2CCH2
CH3O2CCH2
4-ClC6H4
aIsolated yields.

P2O5-Hexamethyldisiloxane
3709
could be seen, the reaction is compatible with different aldehydes and acet-
ophenones bearing electron-withdrowing and electron-releasing groups. The
reaction was also carried out effectively with methyl acetoacetate instead of
acetophenone (Table 2, entries 16 and 17).
The products reported in Table 2 are all known compounds, and
their structures were deduced by comparison of melting points and spec-
tral data with authentic samples. To develop the explained method, we
also conducted the reaction with other enolic systems such as 4-hydroxy-
coumarin, 2-naphthol, or 3-hydroxy-2-naphthoic acid; aryl aldehydes;
and acetonitrile in the presence of phosphorus pentoxide and HMDS.
Thus, the reaction of 4-hydroxycoumarin, aromatic aldehydes, and acet-
onitrile in the presence of 1 equivalent of phosphorus pentoxide and
HMDS afforded the corresponding 3-(acetylamino aryl methyl)-4-hydro-
xycoumarins in good yields (Scheme 2).
Similar products were obtained when 2-naphthol or 3-hydroxy-2-
naphthoic acid was used instead of 4-hydroxycoumarin. The results
obtained for these reactions are summarized in Table 3. As shown, good
yields were obtained using aldehydes bearing electron-withdrawing and
electron-releasing groups.
A reasonable mechanism for the formation of compounds 7 is pre-
sented in Scheme 3. Acetonitrile attacks the condensation product of
naphthol derivative and aldehyde in the presence of PPSE to afford the
diionic intermadiate 9, which then hydrolyzes to product 7.
1
The H NMR spectrum of compound 7a exhibited a sharp line at
d ¼ 1.9 ppm for the protons of the methyl group. The methine and NH
protons couple each other, and two doublets were observed for them at
7.1 and 8.7 ppm, respectively. When the 1H NMR spectrum was recorded
after addition of some D2O to the d6-DMSO solution of 7a, the doublet
Scheme 2. Three-component reaction of aromatic aldehydes, 4-hydroxycou-
marin, and acetonitrile promoted by P2O5=HMDS system. Yields refer to the
pure isolated products. All known products have been reported previously in
the literature and were characterized by comparison of melting points and spec-
tral data witha authentic samples.[16]

3710
M. Anary-Abbasinejad, H. Anaraki-Ardakani, and A. Hassanabadi
Table 3. Reaction between 2-naphthol or 3-hydroxy-2-naphthoic acid and aro-
matic aldehydes in acetonitrile in the presence of P2O5 and HMDS
7
R
Ar
Yield (%)a
a
b
c
d
e
f
CO2H
CO2H
CO2H
CO2H
CO2H
CO2H
CO2H
CO2H
CO2H
H
H
H
H
H
H
H
H
H
4-ClC6H4
3-ClC6H4
2-ClC6H4
4-CH3C6H4
4-NO2C6H4
3-NO2C6H4
4-BrC6H4
3-CH3OC6H4
2-CH3OC6H4
Ph
4-ClC6H4
2-CH3C6H4
2-ClC6H4
3-NO2C6H4
4-FC6H4
4-CH3C6H4
4-BrC6H4
3-CH3OC6H4
2-CH3OC6H4
93
95
97
90
90
95
95
90
96
93
95
95
95
94
91
93
95
95
92
g
h
i
j
k
l
m
n
o
p
q
r
s
H
aYields refer to the pure isolated products. Compounds 7a–i were new, and their struc-
tures were deducted by elemental and spectral analysis. Compounds 7j–s were known com-
pounds, and their structures were deduced by comparing their melting points and spectral
data with authentic samples.[17]
related to the NH proton disappeared and the doublet related to the
methine proton converted to a singlet. The protons of two hydroxy
groups resonated in the range of 12.00–13.00 ppm as a very broad signal,
which in some cases was so broadened that was not observed. The
13C NMR spectrum of compound 7a showed 18 distinct signals, consis-
tent with the proposed structure.

P2O5-Hexamethyldisiloxane
3711
Scheme 3. Suggested mechanism for formation of compounds 7.
In summary, here we report a simple and efficient one-pot synthesis of
2-acetylamino ketones, methyl 3-(acetylamino aryl methyl)-3-oxobutano-
ates, 3-(acetylamino aryl methyl)-4-hydroxycoumarins, 1-(acetyl-
amino aryl methyl)-2-naphthols, or 4-(acetylamino aryl methyl)-3-hydroxy-
2-naphthoic acids by three-component reaction of an enolizable compound,
such as acetophenone, methyl acetoacetate, 4-hydroxycoumarin, 2-
naphthol, or 3-hydroxy-2-naphthoic acid; an aromatic aldehyde; and
acetonitrile induced by phosphorus pentoxide and hexamethyldisiloxane.
The advantages of this method are simple, available starting materials,
short reaction times, easy and clean workup, and excellent yields.
EXPERIMENTAL
Melting points were determined with an electrothermal 9100 apparatus.
Elemental analyses were performed using a Heraeus CHN-O-Rapid ana-
lyzer. Mass spectra were recorded on a Finnigan-MAT 8430 mass spec-
trometer operating at an ionization potential of 70 eV. IR spectra were
recorded on a Shimadzu IR-470 spectrometer. 1H and 13C NMR spectra
were recorded on Bruker DRX-500 Avance spectrometer at solution in
d6-DMSO using TMS as internal standard. The chemicals used in this
work were purchased from Fluka (Buchs, Switzerland) and were used
without further purification.
General Procedure for the Preparation of Compounds 3, 5, and 7
To a magnetically stirred solution of acetophenone (3 mmol) and alde-
hyde (3 mmol) in 15 mL acetonitrile, phosphorus pentoxide (3 mmol)

3712
M. Anary-Abbasinejad, H. Anaraki-Ardakani, and A. Hassanabadi
and HMDS (3 mmol) were added at room temperature. The reaction
mixture was then stirred for 3 h at room temperature. The reaction mix-
ture was poured into 50 mL of ice water. The solid product was filtered,
washed with ice water, and recrystallized from ethyl acetate=n-hexane to
give the pure product.
Data
4-[Acetylamino(4-chlorophenyl)methyl]-3-hydroxy-2-
naphthoic Acid (7a)
Yellow powder, mp 262–264 ꢁC, IR (KBr) (nmax cmꢂ1): 3350, 3125–2605,
1725, 1669. Anal. calcd. for C20H16ClNO4: C, 64.96; H, 4.36; N, 3.79%.
1
Found: C, 65.00; H, 4.28; N, 3.85. MS (m=z, %): 369 (11). H NMR
3
(500 MHz, d6-DMSO): d 1.98 (3 H, s, CH3), 7.11 (1 H, d, JHH ¼ 8 HZ,
3
NCH), 7.25–8.62 (9 H, m, aromatic), 8.76 (1 H, d, JHH ¼ 8 Hz, NH),
11.74 (2 H, broad s, 2 OH). 13C NMR (125.8 MHz, d6-DMSO): d
22.97 (C H3), 47.48 (C H), 120.58, 124.08, 128.32, 128.50, 129.17,
129.35, 130.99, 131.29, 133.50 and 153.06 (naphthol moiety), 114.82,
127.41, 135.27 and 141.52 (phenyl moiety), 169.98, 172.71 (2C¼O).
4-[Acetylamino(3-chlorophenyl)methyl]-3-hydroxy-2-
naphthoic Acid (7b)
Yellow powder, mp 258–260 ꢁC, 95%; IR (KBr) (nmax cmꢂ1): 3385, 3155–
2615, 1708, 1668. Anal. calcd. for C20H16ClNO4: C, 64.96; H, 4.36; N,
1
3.79%. Found: C, 65.00; H, 4.28; N, 3.85. MS (m=z, %): 369 (8). H
NMR (500 MHz, d6-DMSO): d 1.99 (3 H, s, CH3), 7.01 (1 H, d,
3JHH ¼ 8 HZ, NCH), 7.27–8.63 (9 H, m, aromatic), 8.71 (1 H, d,
3JHH ¼ 8 Hz, NH), 11.73 (2 H, broad s, 2OH). 13C NMR (125.8 MHz,
d6-DMSO): d 22.95 (CH3), 47.60 (C H), 120.41, 123.51, 124.13, 125.23,
126.11, 126.78, 130.10, 130.49, 133.59 and 154.92 (naphthol moiety),
114.87, 127.39, 131.01, 133.42, 135.26 and 145.16 (phenyl moiety),
170.07, 172.70 (2C¼O).
4-[Acetylamino(2-chlorophenyl)methyl]-3-hydroxy-2-
naphthoic Acid (7c)
Yellow powder, mp 246–248 ꢁC, 95%; IR (KBr) (nmax cmꢂ1): 3390, 3130–
2580, 1729, 1667. Anal. calcd. for C20H16ClNO4: C, 64.96; H, 4.36; N,
1
3.79%. Found: C, 65.00; H, 4.28; N, 3.85. MS (m=z, %): 369 (10). H

P2O5-Hexamethyldisiloxane
3713
NMR (500 MHz, d6-DMSO): d 1.94 (3 H, s, CH3), 7.15 (1 H, d,
3JHH ¼ 8 Hz, NCH), 7.23–8.62 (9 H, m, aromatic), 8.74 (1 H, d,
3JHH ¼ 8 Hz, NH), 11.63 (2 H, broad s, 2OH). 13C NMR (125.8 MHz,
d6-DMSO): d 22.76 (CH3), 47.76 (CH), 119.34, 123.35, 123.93, 126.95,
128.84, 129.75, 129.86, 130.21, 132.66 and 155.38 (naphthol moiety),
114.65, 127.25, 131.01, 133.55, 135.81 and 139.57 (phenyl moiety),
169.29, 172.84 (2C¼O).
4-[Acetylamino(4-methylphenyl)methyl]-3-hydroxy-2-
naphthoic Acid (7d)
White powder, mp 228–230 ꢁC, IR (KBr) (nmax cmꢂ1): 3350, 3182–2630,
1721, 1669. Anal. calcd. for C21H19NO4: C, 72.19; H, 5.48; N, 4.01%.
1
Found: C, 72.34; H, 5.40; N, 4.05. MS (m=z, %): 349 (10). H NMR
(500 MHz, d6-DMSO): d 1.97 (3 H, s, CH3), 2.22 (3 H, s, CH3), 6.95
3
(1H, d, JHH ¼ 8 Hz, NCH), 7.21–8.61 (9 H, m, aromatic), 8.75 (1 H, d,
3JHH ¼ 8 Hz, NH), 11.73 (2 H, broad s, 2OH). 13C NMR (125.8 MHz,
d6-DMSO): d 20.99 and 23.03 (2 C H3), 47.71 (C H), 121.24, 123.96,
126.41, 127.12, 129.13, 129.78, 130.90, 133.21, 135.41 and 154.80
(naphthol moiety), 114.75, 127.39, 135.73 and 139.32 (phenyl moiety),
169.75, 172.78 (2C¼O).
4-[Acetylamino(4-nitrophenyl)methyl]-3-hydroxy-2-
naphthoic Acid (7e)
Yellow powder, mp 253–255 ꢁC, 90%; IR (KBr) (nmax cmꢂ1): 3380, 3134–
2580, 1729, 1671. Anal. calcd. for C20H16N2O6: C, 63.16; H, 4.24; N,
1
7.36%. Found: C, 63.20; H, 4.30; N, 7.40. MS (m=z, %): 380 (8). H
NMR (500 MHz, d6-DMSO): d 1.96 (3 H, s, CH3), 7.12 (1 H, d,
3JHH ¼ 8 Hz, NCH), 7.25–8.65 (9 H, m, aromatic), 8.72 (1 H, d,
3JHH ¼ 8 Hz, NH), 11.76 (2 H, broad s, 2OH). 13C NMR (125.8 MHz,
d6-DMSO): d 22.88 (CH3), 47.96 (CH), 120.05, 123.38, 123.77, 124.20,
127.43, 130.25, 131.05, 133.83, 135.23 and 155.00 (naphthol moiety),
114.92, 127.56, 146.47 and 150.85 (phenyl moiety), 170.28, 172.66
(2C¼O).
4-[Acetylamino(3-nitrophenyl)methyl]-3-hydroxy-2-
naphthoic Acid (7f)
Yellow powder, mp 250–252 ꢁC, 94%; IR (KBr) (nmax cmꢂ1): 3385, 3136–
2527, 1723, 1672. Anal. calcd. for C20H16N2O6: C, 63.16; H, 4.24; N,

3714
M. Anary-Abbasinejad, H. Anaraki-Ardakani, and A. Hassanabadi
7.36%. Found: C, 63.20; H, 4.30; N, 7.40. MS (m=z, %): 380 (7). 1H NMR
(500 MHz, d6-DMSO): d 2.01 (3 H, s, CH3), 7.24–8.65 (10 H, m, aromatic
3
and NCH), 8.77 (1 H, d, JHH ¼ 8 Hz, NH), 11.74 (2 H, broad s, 2OH).
13C NMR (125.8 MHz, d6-DMSO): d 22.92 (CH3), 47.70 (CH), 119.10,
120.81, 121.92, 123.32, 124.25, 130.17, 130.33, 133.85, 135.20 and
155.38 (naphthol moiety), 114.91, 127.25, 131.07, 133.25, 145.08 and
148.22 (phenyl moiety), 170.28, 172.65 (2C¼O).
4-[Acetylamino(4-bromophenyl)methyl]-3-hydroxy-2-
naphthoic Acid (7g)
Yellow powder, mp 235–237 ꢁC, 90%; IR (KBr) (nmax cmꢂ1): 3385, 3150–
2590, 1740, 1663. Anal. calcd. for C20H16BrNO4: C, 57.99; H, 3.89; N,
1
3.38%. Found: C, 58.06; H, 3.95; N, 3.40. MS (m=z, %): 414 (9). H
NMR (500 MHz, d6-DMSO): d 1.99 (3 H, s, CH3), 7.01 (1 H, d,
3JHH ¼ 8 HZ, NCH), 7.31–8.61 (9 H, m, aromatic), 8.72 (1 H, d,
3JHH ¼ 8 Hz, NH), 11.70 (2 H, broad s, 2OH). 13C NMR (125.8 MHz,
d6-DMSO): d 22.97 (CH3), 47.55 (CH), 119.77, 120.53, 124.27, 126.40,
128.70, 129.49, 129.70, 131.40, 132.99 and 156.50 (naphthol moiety),
115.67, 127.10, 137.68 and 141.97 (phenyl moiety), 170.03, 172.05
(2C¼O).
4-[Acetylamino(3-methoxyphenyl)methyl]-3-hydroxy-2-
naphthoic Acid (7h)
Yellow powder, mp 224–226 ꢁC, IR (KBr) (nmax cmꢂ1): 3385, 3118–2521,
1732, 1664. Anal. calcd. for C21H19NO5: C, 69.03; H, 5.24; N, 3.83%.
1
Found: C, 69.10; H, 5.30; N, 3.80. MS (m=z, %): 365 (11). H NMR
(500 MHz, d6-DMSO): d 1.98 (3 H, s, CH3), 3.66 (3 H, s, OCH3), 6.70
3
(1 H, d, JHH ¼ 8 Hz, NCH), 7.11–8.61 (9 H, m, aromatic), 8.70 (1 H,
3
d, JHH ¼ 8 Hz, NH), 11.75 (2 H, broad s, 2OH). 13C NMR
(125.8 MHz, d6-DMSO): d 22.99 (CH3), 47.81 (CH), 55.35 (OCH3),
118.86, 119.75, 121.05, 124.00, 127.37, 129.69, 130.92, 133.29, 135.40,
and 154.80 (naphthol moiety), 111.33, 112.95, 114.75, 129.88, 144.06
and 159.64 (phenyl moiety), 169.81, 172.75 (2C¼O).
4-[Acetylamino(2-methoxyphenyl)methyl]-3-hydroxy-2-
naphthoic acid (7i)
Yellow powder, mp 244–246 ꢁC, IR (KBr) (nmax cmꢂ1): 3395, 3130–2570,
1703, 1669. Anal. calcd. for C21H19NO5: C, 69.03; H, 5.24; N, 3.83%.

P2O5-Hexamethyldisiloxane
3715
1
Found: C, 69.10; H, 5.30; N, 3.80. MS (m=z, %): 365 (9). H NMR
(500 MHz, d6-DMSO): d 1.93 (3 H, s, CH3), 3.58 (3 H, s, OCH3), 7.12–
3
8.61 (10 H, m, aromatic and NCH), 8.74 (1 H, d, JHH ¼ 8 Hz, NH),
11.64 (2 H, broad s, 2OH). 13C NMR (125.8 MHz, d6-DMSO): d 22.76
(CH3), 47.75 (CH), 53.75 (OCH3), 119.33, 123.34, 123.93, 126.95,
128.84, 129.75, 129.87, 130.21, 132.65 and 155.37 (naphthol moiety),
114.64, 127.24, 131.01, 133.55, 135.80 and 139.57 (phenyl moiety),
169.27, 172.83 (2C¼O).
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