Design and synthesis of 3-acyl-2(3H)-benzoxazolone and 3-acyl-2(3H)- benzothiazolone derivatives

Article abstract of DOI:10.1007/s00706-010-0419-9

A simpler and efficient "green" method using solid sodium hydroxide in a solvent mixture of acetone/water was found to catalyze N-acylation of 2(3H)-benzoxazolones and 2(3H)-benzothiazolones for facile and rapid synthesis of N-acyl derivatives in excellent yields. This method was applied to the synthesis of a series of 132 compounds employing a variety of acyl chlorides. Graphical abstract: [Figure not available: see fulltext.]

Full text of DOI:10.1007/s00706-010-0419-9

Monatsh Chem (2011) 142:67–80
DOI 10.1007/s00706-010-0419-9
ORIGINAL PAPER
Design and synthesis of 3-acyl-2(3H)-benzoxazolone
and 3-acyl-2(3H)-benzothiazolone derivatives
•
Faouzi Guenadil Hocine Aichaoui
•
•
Coco N. Kapanda Didier M. Lambert
•
•
Christopher R. McCurdy Jacques H. Poupaert
Received: 13 October 2008 / Accepted: 7 November 2010 / Published online: 2 December 2010
Ó Springer-Verlag 2010
Abstract A simpler and efficient ‘‘green’’ method using
solid sodium hydroxide in a solvent mixture of acetone/
water was found to catalyze N-acylation of 2(3H)-ben-
zoxazolones and 2(3H)-benzothiazolones for facile and
rapid synthesis of N-acyl derivatives in excellent yields.
This method was applied to the synthesis of a series of 132
compounds employing a variety of acyl chlorides.
anticonvulsant agents [2–7]. In particular, 6-benzoyl-2(3H)-
benzoxazolone (CERM 10194) and its sulfur surrogate
(S-14080) underwent clinical trials as anti-inflammatory
analgesics [6–10]. They were found to inhibit not only the
arachidonic inflammatory cascade, but also to induce the
release of an opioid peptide (possibly endomorphin) in
the periphery [1]. Thus, in an effort aimed at developing mild
and flexible strategies to design new 2(3H)-benzoxazolone
libraries and synthesize heterocyclic scaffolds to prepare new
valuable building blocks in medicinal chemistry, we devised
an efficient and green method to get access to a collection of
3-acyl-2(3H)-benzoxazolones and their corresponding sulfur
bioisosters, which are regioisomeric analogs of the proto-
typic CERM 10194 and S-14080 (Fig. 1).
Keywords 2(3H)-Benzoxazolone Á
2(3H)-Benzothiazolone Á N-Acylation reaction Á
Acyl chlorides
Introduction
The 2(3H)-benzoxazolone heterocyclic template has long
been known as a bioisostere of catechol and can be consid-
ered a ‘‘privileged scaffold’’ in the design of new
pharmacophores [1]. Therapeutic applications of this plat-
form are very broad and range from analgesic anti-
inflammatory compounds to anticocaine and neuroprotective
Results and discussion
The synthesis of 3-acyl-2(3H)-benzoxazolones and 3-acyl-
2(3H)-benzothiazolones is well documented in the literature
and makes use of a base-catalyzed acyl transfer process
using either acid halides or anhydrides as acylating agents
and various bases as catalysts, such as pyridine, TEA,
potassium carbonate, etc., in various organic solvents (i.e.,
acetone, THF, DMF) [11–16]. While in our hands these
processes led effectively to the desired acylated species in
fair to good yields, none of them were judged satisfactory to
elaborate a library of the title compounds. All of them
required a certain degree of labor and workup (heating for
several hours, dilution in large volume of water, neutral-
ization, extraction, etc.). We therefore searched for a simpler
alternative method that would fit in the concept of green
chemistry. We were pleased to observe that the reaction of
2(3H)-benzoxazolone with benzoyl chloride proceeded to
completion at room temperature within 30 min when run in
F. Guenadil Á H. Aichaoui
´
Laboratoire de Chimie Pharmaceutique, Departement de Chimie,
Faculte des Sciences, Universite de Badji-Mokhtar,
´
´
23000, BP 12, Annaba, Algeria
C. N. Kapanda Á D. M. Lambert Á J. H. Poupaert (&)
´
Louvain Drug Research Institute, Departement de Chimie
Pharmaceutique (CMFA-Cannabinoid and Endocannabinoid
´
Research Group), Universite Catholique de Louvain,
1200 Brussels, Belgium
e-mail: jacques.poupaert@uclouvain.be
C. R. McCurdy
Department of Medicinal Chemistry, School of Pharmacy,
University of Mississippi, University, MS 38677, USA
123

68
F. Guenadil et al.
All these compounds were characterized for purity by
thin-layer and HPLC chromatography conditions. In 118
samples, the purity exceeded 92%. Their structure was
ascertained by proton and carbon-13 nuclear magnetic
resonance.
H
N
O
X
O
Fig. 1 Structure of CERM 10194 (X=O) and S-14080 (X=S)
Conclusion
In conclusion we developed and optimized a practical
green protocol of N-acylation of 2(3H)-benzoxazolone and
2(3H)-benzothiazolone derivatives. The synthesis route
employed provided ready access to a library of 132
derivatives of 3-acyl-2(3H)-benzoxazolones and 3-acyl-
2(3H)-benzothiazolones with diversification in two differ-
ent positions.
an acetone:water mixture (90:10, v/v) upon addition of solid
sodium hydroxide. The optimum amount of sodium
hydroxide and the acetone:water ratio was tuned by incre-
mental modifications. The recovery of the product was
extremely simple as the final product precipitates. It was
easily filtered off, and this operation could eventually be
automated. To our surprise, use of a phase transfer catalyst
(PEG600 or benzyltrimethylammonium chloride) [17–19]
in typical conditions of solid liquid phase transfer catalysis
gave results similar to those obtained with the simpler ace-
tone:water system, and substitution of NaOH by KOH or
LiOH or changes of acetone by other classical solvents were
found slightly detrimental. A possible explanation of these
special features can be presented: it has been reported indeed
that 4-hydroxy-4-methylpentane-2-one (known as diacetone
alcohol), i.e., the product arising from acetone aldolization,
can coordinate a sodium cation. This species is thus likely to
work as a solid-liquid phase transfer catalyst and can
promote the N-acylation [20, 21]. To expand the diversity at
the 6-position of 2(3H)-benzoxazolone and 2(3H)-ben-
zothiazolone, a first step consisted of the synthesis of the key
structural elements, and Scheme 1 illustrates the reactions
finally adopted.
Experimental
Melting points were determined in open capillary tubes using
an Electrothermal melting point apparatus. IR spectra were
recorded using a dispersion of the product in KBr disks by
means of a Perkin-Elmer 457 spectrometer. 1H and 13C NMR
spectra were recorded in 3-mm tubes at ambient temperature
on a Bruker Avance 400 MHz spectrometer. Compounds
were dissolved in CDCl3 or DMSO-d6 with TMS as internal
reference. Thin-layer chromatography analyses were per-
formed on Merck TLC plates (silica gel, 60 F 254, E. Merck,
Darmstadt, Germany, ref. 5735). All compounds reported
here were routinely checked in two standard solvents, i.e.,
ethyl acetate:acetone:cyclohexane (solvent A, 5:2:3, v/v/v),
and purity reverse-phase thin-layer chromatography condi-
tions were: HPTLC plates RP-18 F-254 S (Merck),
methanol:water (75:25, v/v). All compounds reported were
found homogenous under such TLC and HPLC conditions.
All reagents were obtained commercially from Aldrich and
were used as received. All solvents were of the ACS.
The classical nitration procedure using nitric acid yiel-
ded the corresponding 6-nitro-2(3H)-benzoxazolone and
6-nitro-2(3H)-benzothiazolone in 79 and 78% yields [22].
The aromatic bromination reaction of 2(3H)-benzoxazo-
lone and 2(3H)-benzothiazolone with bromine in the
presence of sodium acetate in glacial acetic acid offers one
of the most direct and viable methods for the synthesis of
6-bromo derivatives in satisfactory yields after 24 h [23].
To improve the yield, an alternative bromination reaction
was employed using NBS in water acidified with sulfuric
acid affording 1b and 2b with an improved yield (83–85%)
and a shorter reaction time of 8 h [24]. The Friedel-Crafts
acylation reaction taking advantage of the AlCl3–DMF
complex as catalyst is well known and provides ready
access to substituted 6-acyl-2(3H)-benzoxazolones and
6-acyl-2(3H)-benzothiazolones in high yields [25–27].
According to the synthetic procedure shown in Scheme 1,
we synthesized a library of 132 compounds, employing 11
acid chlorides, 2(3H)-benzoxazolone, 2(3H)-benzothiazo-
lone, and 10 of their derivatives (Fig. 2); 28 of them have
been described previously [11–16, 28–46].
Procedure for the nitration reaction
To 1 mmol of 2(3H)-benzoxazolone or 2(3H)-ben-
zothiazolone was added 10 cm3 HNO3 (68%) under
stirring. The reaction mixture was heated at 50 °C for
30 min and kept at room temperature for 2 h. After that,
50 cm3 H2O was added to the reaction mixture, stirred for
15 min, filtered, washed, dried and crystallized from eth-
1
anol. The physical properties (m.p., IR, H NMR) are in
accordance with published data [22, 47].
Procedure for the bromination reaction in water
To a suspension of 1 mmol of 2(3H)-benzoxazolone or
2(3H)-benzothiazolone in 10 cm3 H2O, 1 mmol of NBS
123

Design and synthesis of 3-acyl-2(3H)-benzoxazolone and 3-acyl-2(3H)-benzothiazolone derivatives
69
Scheme 1
H
N
O
X
a
b
c
H
N
H
N
H
N
O
O
O
R
X
NO2
X
X
Br
O
1a: X=O, 2a: X=S
1b: X=O, 2b: X=S
R=CH3-;
3c: X=O,
4c
: X=S
1c
R=CH3CH2-; : X=O,
2c: X=S
5c
6c
R= C6H5 -;
: X=O,
: X=S
d
O
R2
N
O
R1
X
Fig. 2 Structural diversity of
the 3-acyl-2(3H)-benzoxazolone
and 3-acyl-2(3H)-
R1=
-Br
a1-a11 1a1-1a11 1b1-1b11 1c1-1c11
-H
-NO2
CH3CO-
CH3CH2CO-
C6H5CO-
3c1-3c11
4c1-4c11
5c1-5c11
6c1-6c11
X=O
X=S
benzothiazolone derivatives
b1-b11
2a1-2a11 2b1-2b11 2c1-2c11
R2 =
CH3-
CH3CH2-
(CH3)2CH-
(CH3)3C-
C6H5-CH2-
1
3
4
5
2
m-CH3-C6H4-
C6H5-CH2CH2-
C6H5-
-CH -C H -
p
3
6 4
6
7
8
9
-Cl-C H -
-NO -C H -
o
p
6
4
2
6 4
10
11
123

70
F. Guenadil et al.
(d, 1Ar-H) ppm; 13C NMR (CDCl3): d = 42.87, 109.88,
116.25, 124.90, 125.43, 127.57, 127.88, 128.74, 129.85,
132.57, 142.31, 151.30, 170.55 ppm.
was added and the reaction mixture heated to 60 °C while
stirring. H2SO4 (40% aq solution, 2 mmol) was then added
and stirring continued for 8 h. After that, the reaction
mixture was cooled, and 30 cm3 of water was added and
stirred for 15 min, filtered, washed, dried and crystallized
3-(3-Phenylpropionyl)-2(3H)-benzoxazolone
(a6, C16H13NO3)
1
from ethanol. The physical properties (m.p., IR, H NMR)
ꢀ
Yield 96%; m.p.: 119 °C; IR (KBr): m = 2,936, 1,796,
are in accordance with published data [23, 48].
1
1,728, 1,625, 1,602 cm-1; H NMR (CDCl3): d = 3.08 (t,
1CH2), 3.42 (t, 1CH2), 7.31–7.10 (m, 8Ar-H), 8.04 (d, 1Ar-
H) ppm; 13C NMR (CDCl3): d = 29.94, 38.47, 109.89,
116.07, 124.86, 125.35, 126.47, 127.80, 128.60, 128.62,
140.10, 142.32, 151.35, 171.74 ppm.
General procedure for the Friedel-Crafts acylation
using AlCl3-DMF
In a three-neck round-bottom flask (250 cm3), 53.3 g AlCl3
(0.4 mol) was placed. The flask was then equipped with a
reflux condenser with a CaCl2 tube and a magnetic stirrer.
Dimethylformamide (8.6 cm3, 0.115 mol) was added
dropwise over 10 min. The flask was then placed in an oil
bath at 45 °C, and the substrate 2(3H)-benzoxazolone or
2(3H)-benzothiazolone (0.04 mol) was added in portions
over 5 min. Care was taken during this addition to ensure
the formation of a homogeneous paste. The acylating agent
(0.06 mol) was then added dropwise over 10 min. The
temperature was subsequently raised to 85 °C. After
cooling, the products were isolated by addition of ice. The
precipitate was stirred for 1 h, collected on a Buchner
funnel, dried, and crystallized from ethanol. The physical
properties (m.p., IR, 1H NMR) are in accordance with
published data [9, 17].
3-(3-Methylbenzoyl)-2(3H)-benzoxazolone
(a8, C15H11NO3)
ꢀ
Yield 97%; m.p.: 130–132 °C; IR (KBr): m = 2,924, 1,796,
1,701, 1,618, 1,603 cm-1 1H NMR (CDCl3): d = 2.43
;
(3H, s, 1CH3), 7.20–7.70 (7H, m, 7Ar-H), 7.98 (1H, d,
J = 8.02 Hz, 1Ar-H) ppm; 13C NMR (CDCl3): d = 21.35,
110.14, 114.28, 124.40, 126.75, 128.24, 130.04, 132.05,
134.13, 138.34, 142.76, 151.01, 167.99 ppm.
3-(2,2-Dimethylpropionyl)-2(3H)-benzothiazolone
(b4, C12H13NO2S)
ꢀ
Yield 77%; m.p.: 54 °C; IR (KBr): m = 2,928, 1,718,
1,660, 1,618 cm-1; 1H NMR (CDCl3): d = 1.69 (s, 3CH3),
7.39–7.28 (m, 3Ar-H), 8.06 (d, 1Ar-H) ppm; 13C NMR
(CDCl3): d = 25.29, 41.17, 117.63, 122.57, 123.27,
126.50, 134.70, 138.83, 170.21, 172.94 ppm.
3-(3-Phenylpropionyl)-2(3H)-benzothiazolone
(b6, C16H13NO2S)
General procedure for the N-acylation reaction
in acetone-water mixture
ꢀ
Yield 95%; m.p.: 84 °C; IR (KBr): m = 2,962, 2,917,
1,706, 1,681, 1,618, 1,578 cm-1 1H NMR (CDCl3):
;
To a solution of 0.6 g NaOH (0.015 mol) in 5 cm3 water
was added under stirring 0.012 mol of 2(3H)-benzoxazo-
lone or 2(3H)-benzothiazolone or their derivatives, then
45 cm3 of acetone was added to this solution. After stirring
for 15 min, 0.015 mol acylating was added, and the
resulting mixture was stirred for 30 min at room temper-
ature. The reaction mixture was concentrated under
reduced pressure and the residue triturated with water,
filtered, dried, and crystallized from ethanol to afford good
purity of the compounds.
d = 3.08 (t, 1CH2), 3.45 (t, 1CH2), 7.40–7.10 (m, 8Ar-
H), 8.22 (d, 1Ar-H) ppm; 13C NMR (CDCl3): d = 29.09,
39.31, 116.46, 120.48, 121.24, 121.32, 124.13, 124.99,
125.66, 127.20, 127.22, 127.76, 133.39, 138.94, 169.66,
172.00 ppm.
3-(3-Methylbenzoyl)-2(3H)-benzothiazolone
(b8, C15H11NO2S)
ꢀ
Yield 90%; m.p.: 138–140 °C; IR (KBr): m = 2,919, 1,715,
1,670, 1,604 cm-1; 1H NMR (DMSO-d6): d = 2.33 (3H, s,
1CH3), 7.20–7.66 (7H, m, 7Ar-H), 7.98 (1H, m, 1Ar-H)
ppm; 13C NMR (DMSO-d6): d = 21.29, 114.82, 122.13,
122.67, 124.90, 127.39, 128.58, 130.55, 132.65, 134.85,
135.12, 138.71,168.34, 169.39 ppm.
3-(2,2-Dimethylpropionyl)-2(3H)-benzoxazolone
(a4, C12H13NO3)
ꢀ
Yield 95%; m.p.: 62 °C; IR (KBr): m = 2,974, 1,797,
1
1,716, 1,630, 1,599 cm-1; H NMR (CDCl3): d = 1.49 (s,
3CH3), 7.30–7.00 (m, 3Ar-H), 7.90 (m, 1Ar-H) ppm; 13C
NMR (CDCl3): d = 26.22, 42.80, 109.75, 116.45, 124.47,
124.87, 129.38, 142.07, 150.12, 178.34 ppm.
3-(4-Methylbenzoyl)-2(3H)-benzothiazolone
(b9, C15H11NO2S)
ꢀ
Yield 89%; m.p.: 88 °C; IR (KBr): m = 2,933, 1,702,
1,667, 1,588 cm-1; 1H NMR (CDCl3): d = 2.44 (s, 1CH3),
7. 12–7. 30 (m, 3Ar-H), 7.51–7.38 (m, 2Ar-H), 7.76 (m,
2Ar-H), 7.98 (d, 1Ar-H) ppm; 13C NMR (CDCl3):
d = 20.41, 113.27, 120.95, 121.22, 123.34, 125.92,
3-(Phenylacetyl)-2(3H)-benzoxazolone (a5, C15H11NO3)
ꢀ
Yield 97%; m.p.: 156 °C; IR (KBr): m = 2,929, 1,798,
1
1,725, 1,627, 1,604 cm-1; H NMR (CDCl3): d = 4.45 (s,
1CH2), 7.21–7.10 (m, 3Ar-H), 7.40–7.26 (m, 5Ar-H), 8.04
123

Design and synthesis of 3-acyl-2(3H)-benzoxazolone and 3-acyl-2(3H)-benzothiazolone derivatives
71
128.05, 128.11, 128.30, 129.03, 129.17, 133.53, 144.19,
167.19, 167.95 ppm.
NMR (DMSO-d6): d = 20.71, 105.90, 114.27, 120.75,
126.92, 128.06, 129.92, 131.73, 134.16, 137.64, 142.30,
144.05, 150.28, 167.18 ppm.
3-(2-Chlorobenzoyl)-2(3H)-benzothiazolone
(b10, C14H8ClNO2S)
3-(4-Methylbenzoyl)-6-nitro-2(3H)-benzoxazolone
(1a9, C15H10N2O5)
ꢀ
Yield 96%; m.p.: 80–81 °C; IR (KBr): m = 1,706, 1,683,
1
1,618, 1,593 cm-1; H NMR (DMSO-d6): d = 7.19–7.65
ꢀ
Yield 92%; m.p.: 191–193 °C; IR (KBr): m = 2,926, 1,799,
(7H, m, 7Ar-H), 8.14 (1H, d, J = 7.98 Hz, 1Ar-H) ppm;
13C NMR (DMSO-d6): d = 116.28, 121.80, 121.95,
125.42, 126.84, 129.08, 129.51, 130.59, 131.01, 131.91,
133.65, 134.41, 166.45, 169.30 ppm.
1,694, 1,610 cm-1 1H NMR (DMSO-d6): d = 2.44
;
(3H, s, 1CH3), 7.35–7.80 (4H, m, 4Ar-H), 7.98 (1H, d,
J = 7.99 Hz, 1Ar-H), 8.20–8.32 (2H, m, 2Ar-H) ppm; 13C
NMR (DMSO-d6): d = 21.27, 105.89, 114.21, 120.71,
127.87, 128.75, 129.28, 130.05, 134.24, 137.59, 142.27,
150.27, 167.27 ppm.
3-(2-Methylpropionyl)-6-nitro-2(3H)-benzoxazolone
(1a3, C11H10BrN2O5)
ꢀ
Yield 75%; m.p.: 134–136 °C; IR (KBr): m = 2,925, 1,793,
1,712, 1,615, 1,601 cm-1; 1H NMR (DMSO-d6): d = 1.36
(6H, d, 2CH3), 3.84 (1H, m, 1CH), 8.09 (1H, d,
J = 7.91 Hz, 1Ar-H), 8.27 (2H, m, 2Ar-H) ppm; 13C
NMR (DMSO-d6): d = 18.63, 34.38, 105.87, 116.48,
121.72, 133.22, 142.02, 145.07, 150.90, 176.58 ppm.
3-(2-Chlorobenzoyl)-6-nitro-2(3H)-benzoxazolone
(1a10, C14H7ClN2O5)
ꢀ
Yield 92%; m.p.: 133–135 °C; IR (KBr): m = 1,750, 1,712,
1,614 cm-1; 1H NMR (DMSO-d6): d = 7.63–7.82 (4H, m,
4Ar-H), 8.08 (1H, d, J = 7.89 Hz, 1Ar-H), 8.27 (2H, m,
2Ar-H) ppm; 13C NMR (DMSO-d6): d = 109.56, 113.38,
118.89, 120.65, 126.88, 128.16, 130.35, 137.59, 139.39,
142.39, 150.87, 167.64 ppm.
3-(2,2-Dimethylpropionyl)-6-nitro-2(3H)-benzoxazolone
(1a4, C12H12N2O5)
ꢀ
Yield 73%; m.p.: 226–227 °C; IR (KBr): m = 2,929, 1,760,
1,725, 1,610, 1,599 cm-1; 1H NMR (DMSO-d6): d = 1.29
(9H, s, 3CH3), 8.10 (1H, d, J = 7.88 Hz, 1Ar-H), 8.26 (2H,
m, 2Ar-H) ppm; 13C NMR (DMSO-d6): d = 26.97, 39.27,
105.47, 109.41, 114.97, 120.83, 136.93, 142.83, 154.28,
172.28 ppm.
6-Nitro-3-(4-nitrobenzoyl)-2(3H)-benzoxazolone
(1a11, C14H7N3O7)
ꢀ
Yield 76%; m.p.: 232–234 °C; IR (KBr): m = 1,760, 1,699,
1,602 cm-1; 1H NMR (DMSO-d6): d = 7.83–8.09 (3H, m,
3Ar-H), 8.24–8.38 (4H, m, 4Ar-H) ppm; 13C NMR
(DMSO-d6): d = 114.34, 116.63, 118.74, 123.58, 123.98,
128.22, 130.78, 137.41, 142.68, 150.18, 167.73 ppm.
6-Nitro-3-(phenylacetyl)-2(3H)-benzoxazolone
(1a5, C15H10N2O5)
ꢀ
6-Bromo-3-propionyl-2(3H)-benzoxazolone
(1b2, C10H8BrNO3)
Yield 89%; m.p.: 161–163 °C; IR (KBr): m = 2,918, 1,795,
1
1,736, 1,611 cm-1; H NMR (CDCl3): d = 4.43 (2H, s,
ꢀ
Yield 97%; m.p.: 145 °C; IR (KBr): m = 2,922, 1,803,
1CH2), 7.20–7.45 (5H, m, 5Ar-H), 8.12 (1H, d, J =
7.78 Hz, 1Ar-H), 8.26–8.30 (2H, m, 2 Ar–H) ppm; 13C
NMR (CDCl3): d = 42.16, 109.41, 115.09, 121.03, 127.65,
128.30, 129.32, 130.63, 133.62, 141.61, 142.62, 150.57,
170.74 ppm.
1
1,725, 1,618, 1,603 cm-1; H NMR (CDCl3): d = 1.29 (t,
1CH3), 3.10 (q, 1CH2), 7.38 (m, 2Ar-H), 7.93 (d, 1Ar-H)
ppm; 13C NMR (CDCl3): d = 7.99, 30.53, 113.33, 117.14,
117.89, 127.65, 127.86, 142.75, 151.25, 173.19 ppm.
6-Bromo-3-(2-methylpropionyl)-2(3H)-benzoxazolone
(1b3, C11H10BrNO3)
6-Nitro-3-(3-phenylpropionyl)-2(3H)-benzoxazolone
(1a6, C16H12N2O5)
ꢀ
ꢀ
Yield 93%; m.p.: 84 °C; IR (KBr): m = 2,973, 1,803,
Yield 91%; m.p.: 149 °C; IR (KBr): m = 2,931, 1,806,
1,719, 1,600 cm-1; 1H NMR (CDCl3): d = 1.31 (d, 2CH3),
1,735, 1,615 cm-1 1H NMR (DMSO-d6): d = 2.98 (t,
;
3.81 (m, 1CH), 7.38 (m, 2Ar-H), 7.97 (d, 1Ar-H) ppm; 13
C
2CH2), 3.33 (t, 2CH2), 7.30–7.10 (m, 5Ar-H), 8.10 (d, 1Ar-
H), 8.25 (m, 1Ar-H), 8.37 (s, 1Ar-H) ppm; 13C NMR
(DMSO-d6): d = 28.93, 37.79, 105.83, 115.00, 120.99,
126.13, 128.38, 133.39, 140.29, 141.80, 144.07, 150.62,
171.64 ppm.
NMR (CDCl3): d = 18.59, 34.02, 113.35, 117.26, 117.77,
127.70, 127.79, 142.64, 151.26, 176.66 ppm.
6-Bromo-3-(2,2-dimethylpropionyl)-2(3H)-benzoxazolone
(1b4, C12H12BrNO3)
ꢀ
Yield 87%; m.p.: 74–76 °C; IR (KBr): m = 2,926, 1,780,
3-(3-Methylbenzoyl)-6-nitro-2(3H)-benzoxazolone
(1a8, C15H10N2O5)
1,732, 1,619, 1,599 cm-1 1H NMR (CDCl3): d = 1.31
;
ꢀ
(9H, s, 3CH3), 7.38 (2H, m, 2Ar-H), 7.97 (1H, d,
J = 7.79 Hz, 1Ar-H) ppm; 13C NMR (CDCl3): d = 17.24,
32.67, 112.01, 115.92, 116.43, 125.86, 126.44, 152.20,
175.31 ppm.
Yield 90%; m.p.: 167–169 °C; IR (KBr): m = 2,923, 1,785,
1,715, 1,609 cm-1 1H NMR (DMSO-d6): d = 2.48
(3H, s, 1CH3), 7.36–7.79 (4H, m, 4Ar-H), 7.95 (1H, d,
;
J = 7.89 Hz, 1Ar-H), 8.25–8.32 (2H, m, 2Ar-H) ppm; 13C
123

72
F. Guenadil et al.
6-Bromo-3-(phenylacetyl)-2(3H)-benzoxazolone
(1b5, C15H10BrNO3)
6-Acetyl-3-propionyl-2(3H)-benzoxazolone
(1c2, C12H11NO4)
ꢀ
ꢀ
Yield 90%; m.p.: 175–177 °C; IR (KBr): m = 2,922, 1,755,
Yield 90%; m.p.: 167–169 °C; IR (KBr): m = 2,924, 1,775,
1,729, 1,620, 1,602 cm-1 1H NMR (CDCl3): d = 4.46
;
1,721, 1,680, 1,626 cm-1 1H NMR (CDCl3): d = 1.30
;
(2H, s, 1CH2), 7.26–7.46 (7H, m, 7Ar-H), 7.94 (1H, d,
J = 7.89 Hz, 1Ar-H) ppm; 13C NMR (CDCl3): d = 40.34,
111.06, 114.72, 115.62, 124.19, 125.21, 125.53, 126.31,
127.32, 129.72, 140.18, 148.21, 167.85 ppm.
(3H, t, 1CH3), 2.62 (3H, s, 1CH3), 3.17 (2H, q, 1CH2), 7.82
(1H, s, 1Ar-H), 7.93 (1H, d, J = 7.78 Hz, 1Ar-H), 8.16
(1H, d, J = 7.78 Hz, 1Ar-H) ppm; 13C NMR (CDCl3):
d = 7.91, 28.43, 30.58, 107.27, 113.40, 123.85, 129.43,
132.50, 141.98, 151.43, 172.35, 198.46 ppm.
6-Bromo-3-(3-phenylpropionyl)-2(3H)-benzoxazolone
(1b6, C16H12BrNO3)
6-Acetyl-3-(2-methylpropionyl)-2(3H)-benzoxazolone
(1c3, C13H13NO4)
ꢀ
Yield 91%; m.p.: 125–127 °C; IR (KBr): m = 2,927, 1,798,
ꢀ
Yield 84%; m.p.: 127 °C; IR (KBr): m = 2,981, 1,805,
1,725, 1,621, 1,604 cm-1 1H NMR (CDCl3): d = 3.13
;
1,727, 1,680, 1,618, 1,600 cm-1 1H NMR (CDCl3):
;
(2H, t, 2CH2), 3.42 (2H, t, 2CH2), 7.18–7.47 (7H, m, 7Ar-
H), 7.96 (1H, d, J = 7.98 Hz, 1Ar-H) ppm; 13C NMR
(CDCl3): d = 29.80, 38.38, 113.49, 117.11, 117.61,
126.30, 126.37, 127.90, 128.35, 128.46, 139.86, 142.64,
150.49, 171.44 ppm.
d = 1.45 (d, 2CH3), 2.62 (s, 1CH3), 3.86 (m, 1CH), 7.80
(s, 1Ar-H), 7.87 (d, 1Ar-H), 8.12 (d, 1Ar-H) ppm; 13C NMR
(CDCl3): d = 16.57, 24.48, 32.10, 107.26, 113.70, 123.86,
129.76, 132.39, 142.21, 150.75, 174.72, 198.59 ppm.
6-Acetyl-3-(2,2-dimethylpropionyl)-2(3H)-benzoxazolone
(1c4, C14H15NO4)
6-Bromo-3-(3-methylbenzoyl)-2(3H)-benzoxazolone
(1b8, C15H10BrNO3)
ꢀ
Yield 84%; m.p.: 142–143 °C; IR (KBr): m = 2,929, 1,760,
1,720, 1,670, 1,618 cm-1; 1H NMR (DMSO-d6): d = 1.32
(9H, s, 3CH3), 2.52 (3H, s, 1CH3), 7.82 (1H, s, 1Ar-H),
7.84 (1H, d, J = 7.85 Hz, 1Ar-H), 8.13 (1H, d,
J = 7.85 Hz, 1Ar-H) ppm; 13C NMR (DMSO-d6):
d = 24.95, 24.37, 38.37, 107.41, 107.71, 123.42, 129.61,
132.18, 141.66, 152.79, 174.20, 194.71 ppm.
ꢀ
Yield 87%; m.p.: 147–150 °C; IR (KBr): m = 2,923, 1,797,
1
1,711, 1,618 cm-1; H NMR (CDCl3): d = 2.48 (3H, s,
1CH3), 7.20–7.60 (6H, m, 6Ar-H), 7.97 (1H, d, J =
7.89 Hz, 1Ar-H) ppm; 13C NMR (CDCl3): d = 19.46,
111.28, 113.69, 115.26, 125.24, 126.28, 126.73, 127.17,
127.62, 128.25, 140.59, 142.62, 143.13, 150.49, 164.85
ppm.
6-Acetyl-3-(phenylacetyl)-2(3H)-benzoxazolone
(1c5, C17H13NO4)
6-Bromo-3-(4-methylbenzoyl)-2(3H)-benzoxazolone
(1b9, C15H10BrNO3)
Yield 91%; m.p.: 108–110 °C; IR (KBr): ꢀm = 2,930, 1,785,
1,700, 1,676, 1,618 cm-1 1H NMR (CDCl3): d = 2.56
;
Yield 93%; m.p.: 142–144 °C; IR (KBr): ꢀm = 2,923, 1,776,
1,693, 1,610, 1,600 cm-1 1H NMR (CDCl3): d = 2.46
;
(3H, s, 1CH3), 4.44 (2H, s, 1CH2), 7.24–7.39 (5H, m, 5Ar-
H), 7.78–7.90 (2H, m, 2Ar-H), 8.10 (1H, d, J = 8.02 Hz,
1Ar-H) ppm; 13C NMR (CDCl3): d = 24.16, 36.08,
107.95, 113.21, 123.81, 126.24, 128.44, 128.91, 129.44,
132.17, 137.42, 140.02, 148.62, 169.17, 193.62 ppm.
(3H, s, 1CH3), 7.20–7.50 (6H, m, 6Ar-H), 7.95 (1H, d,
J = 7.88 Hz, 1Ar-H) ppm; 13C NMR (CDCl3): d = 21.85,
113.62, 116.98, 117.66, 127.70, 128.66, 129.14, 129.91,
143.09, 145.86, 152.19, 170.19 ppm.
6-Bromo-3-(2-chlorobenzoyl)-2(3H)-benzoxazolone
(1b10, C14H7BrClNO3)
6-Acetyl-3-(3-phenylpropionyl)-2(3H)-benzoxazolone
(1c6, C18H15NO4)
ꢀ
Yield 89%; m.p.: 90–92 °C; IR (KBr): m = 1,750, 1,708,
ꢀ
Yield 93%; m.p.: 147–148 °C; IR (KBr): m = 2,938, 1,760,
1
1,618, 1,590 cm-1; H NMR (DMSO-d6): d = 7.29–7.48
1,699, 1,680, 1,603 cm-1; 1H NMR (DMSO-d6): d = 2.61
(3H, s, 1CH3), 3.05 (2H, t, 1CH2), 3.29 (2H, t, 1CH2),
7.11–7.32 (5H, m, 5Ar-H), 7.83–7.94 (2H, s, 2Ar-H), 8.11
(1H, d, J = 7.99 Hz, 1Ar-H) ppm; 13C NMR (DMSO-d6):
d = 21.86, 28.89, 37.82, 108.21, 115.22, 120.79, 124.13,
126.11, 128.19, 129.69, 132.88, 133.19, 142.29, 152.20,
171.96, 196.99 ppm.
(2H, m, 2Ar-H), 7.64–7.85 (4H, m, 4Ar-H), 8.07 (1H, d,
J = 8.10 Hz, 1Ar-H) ppm; 13C NMR (DMSO-d6): d =
113.63, 116.89, 117.23, 127.78, 128.67, 129.43, 129.70,
130.14, 132.81, 142.89, 149.26, 167.92 ppm.
3,6-Diacetyl-2(3H)-benzoxazolone (1c1, C11H9NO4)
ꢀ
Yield 90%; m.p.: 158 °C; IR (KBr): m = 2,927, 1,802,
1,731, 1,677, 1,618, 1,604 cm-1 1H NMR (CDCl3):
;
6-Acetyl-3-benzoyl-2(3H)-benzoxazolone
(1c7, C16H11NO4)
d = 2.65 (s, 1CH3), 2.89 (s, 1CH3), 7.79 (s, 1Ar-H), 7.90
(d, 1Ar-H), 8.16 (d, 1Ar-H) ppm; 13C NMR (CDCl3):
d = 22.98, 24.59, 107.48, 113.58, 124.05, 129.76, 132.37,
142.18, 150.82, 173.72, 198.68 ppm.
ꢀ
Yield 83%; m.p.: 63–65 °C; IR (KBr): m = 2,924, 1,790,
1,724, 1,670, 1,599 cm-1 1H NMR (CDCl3): d = 2.60
(3H, s, 1CH3), 7.40–7.70 (5H, m, 5Ar-H), 7.78–7.90 (2H,
;
123

Design and synthesis of 3-acyl-2(3H)-benzoxazolone and 3-acyl-2(3H)-benzothiazolone derivatives
73
m, 2Ar-H), 8.06 (1H, d, J = 7.92 Hz, 1Ar-H) ppm; 13C
NMR (CDCl3): d = 24.37, 107.50, 112.36, 123.69, 126.92,
127.46, 128.10, 128.36, 129.95, 132.37, 148.48, 165.21,
193.90 ppm.
3-(2,2-Dimethylpropionyl)-6-nitro-2(3H)-benzothiazolone
(2a4, C12H12N2O4S)
ꢀ
Yield 79%; m.p.: 218–219 °C; IR (KBr): m = 2,927, 1,709,
1,675, 1,602 cm-1; 1H NMR (DMSO-d6): d = 1.46 (9H, s,
3CH3), 8.15 (1H, d, J = 7.98 Hz, 1Ar-H), 8.34 (2H, m,
2Ar-H) ppm; 13C NMR (DMSO-d6): d = 27.23, 44.75,
112.58, 118.70, 122.74, 124.66, 139.61, 142.36, 169.66,
172.91 ppm.
6-Acetyl-3-(3-methylbenzoyl)-2(3H)-benzoxazolone
(1c8, C17H13NO4)
ꢀ
Yield 81%; m.p.: 69–70 °C; IR (KBr): m = 2,922, 1,785,
1,717, 1,671, 1,618 cm-1 1H NMR (CDCl3): d = 2.50
;
6-Nitro-3-(phenylacetyl)-2(3H)-benzothiazolone
(2a5, C15H10N2O4S)
(3H, s, 1CH3), 2.59 (3H, s, 1CH3), 7.20–7.39 (4H, m, 4Ar-
H), 7.78–7.91 (2H, m, 2Ar-H), 8.04 (1H, d, J = 7.88 Hz,
1Ar-H) ppm; 13C NMR (CDCl3): d = 21.28, 26.55,
107.90, 112.63, 124.41, 127.39, 128.54, 128.85, 133.33,
133.54, 142.27, 150.69, 165.38, 193.95 ppm.
ꢀ
Yield 91%; m.p.: 236–238 °C; IR (KBr): m = 2,929, 1,709,
1,670, 1,619, 1,606 cm-1; 1H NMR (DMSO-d6): d = 4.46
(2H, s, 1CH2), 7.16-7.50 (5H, m, 5Ar-H), 8.18 (1H, d,
J = 7.75 Hz, 1Ar-H), 8.28–8.39 (2H, m, 2Ar-H) ppm; 13C
NMR (DMSO-d6): d = 40.96, 116.82, 121.92, 123.42,
127.85, 128.81, 129.34, 129.68, 132.26, 139.12, 143.92,
169.53, 171.84 ppm.
6-Acetyl-3-(4-methylbenzoyl)-2(3H)-benzoxazolone
(1c9, C17H13NO4)
ꢀ
Yield 89%; m.p.: 89–91 °C; IR (KBr): m = 2,924, 1,775,
1,712, 1,677, 1,609 cm-1 1H NMR (CDCl3): d =
;
6-Nitro-3-(3-phenylpropionyl)-2(3H)-benzothiazolone
(2a6, C16H12N2O4S)
2.49 (3H, s, 1CH3), 2.58 (3H, s, 1CH3), 7.21–7.38
(4H, m, 4Ar-H), 7.76–7.90 (2H, m, 2Ar-H), 8.02
(1H, d, J = 7.89 Hz, 1Ar-H) ppm; 13C NMR (CDCl3):
d = 20.07, 24.82, 107.92, 112.65, 124.46, 127.43, 127.81,
128.56, 128.86, 133.34, 133.58, 142.29, 150.72, 165.41,
194.21 ppm.
ꢀ
Yield 91%; m.p.: 158 °C; IR (KBr): m = 2,944, 1,706,
1,668, 1,590 cm-1; 1H NMR (CDCl3): d = 3.15 (t, 1CH2),
3.50 (t, 1CH2), 7.10–7.34 (m, 5Ar-H), 8.09 (d, 1Ar-H),
8.34 (s, 1Ar-H), 8.43 (d, 1Ar-H) ppm; 13C NMR (CDCl3):
d = 30.29, 40.66, 117.65, 117.78, 122.73, 123.44, 126.55,
128.52, 128.64, 139.11, 139.77, 144.80, 169.84, 173.14
ppm.
6-Acetyl-3-(2-chlorobenzoyl)-2(3H)-benzoxazolone
(1c10, C16H10ClNO4)
Yield 87%; m.p.: 70–71 °C; IR (KBr): ꢀm = 2,939, 1,780,
3-(3-Methylbenzoyl)-6-nitro-2(3H)-benzothiazolone
(2a8, C15H10N2O4S)
1,718, 1,680, 1,619 cm-1 1H NMR (CDCl3): d = 2.62
;
(3H, s, 1CH3), 7.34–7.63 (4H, m, 4Ar-H), 7.80–7.94 (2H,
m, 2Ar-H), 8.09 (1H, d, J = 8.00 Hz, 1Ar-H) ppm; 13C
NMR (CDCl3): d = 26.82, 109.91, 115.34, 127.17, 128.15,
129.01, 130.04, 131.89, 132.82, 133.75, 134.42, 135.46,
142.29, 150.67, 160.61, 196.15 ppm.
Yield 89%; m.p.: 107–108 °C; IR (KBr): ꢀm = 2,929, 1,709,
1,660, 1,610 cm-1; 1H NMR (DMSO-d6): d = 2.46 (3H, s,
1CH3), 7.27–7.75 (4H, m, 4Ar-H), 7.98 (1H, d, J =
7.92 Hz, 1Ar-H), 8.26–8.34 (2H, m, 2Ar-H) ppm; 13C
NMR (DMSO-d6): d = 21.31, 114.21, 118.43, 122.64,
124.04, 127.67, 128.48, 130.80, 131.63, 135.34, 135.99,
139.13, 144.18, 168.34, 169.39 ppm.
6-Acetyl-3-(4-nitrobenzoyl)-2(3H)-benzoxazolone
(1c11, C16H10N2O6)
ꢀ
Yield 78%; m.p.: 111–113 °C; IR (KBr): m = 2,926, 1,760,
3-(4-Methylbenzoyl)-6-nitro-2(3H)-benzothiazolone
(2a9, C15H10N2O4S)
1,700, 1,670, 1,618 cm-1; 1H NMR (DMSO-d6): d = 2.64
(3H, s, 1CH3), 7.79–7.99 (4H, m, 4Ar-H), 8.12 (1H, d,
J = 8.09 Hz, 1Ar-H), 8.23–8.32 (2H, m, 2Ar-H) ppm; 13C
NMR (DMSO-d6): d = 21.23, 108.28, 121.25, 123.60,
124.37, 128.40, 131.73, 136.08, 139.41, 142.99, 156.04,
165.63, 195.17 ppm.
ꢀ
Yield 94%; m.p.: 142–144 °C; IR (KBr): m = 2,929, 1,711,
1
1,660, 1,616 cm-1; H NMR (CDCl3): d = 2.48 (3H, s,
1CH3), 7.29–7.79 (4H, m, 4Ar-H), 8.04 (1H, d, J =
7.98 Hz, 1Ar-H), 8.22–8.30 (2H, m, 2Ar-H) ppm; 13C
NMR (CDCl3): d = 21.99, 114.41, 118.41, 122.13, 124.02,
126.24, 128.74, 129.95, 130.75, 131.50, 135.78, 139.64,
145.58, 167.83, 169.87 ppm.
3-(2-Methylpropionyl)-6-nitro-2(3H)-benzothiazolone
(2a3, C11H10N2O4S)
ꢀ
Yield 88%; m.p.: 142 °C; IR (KBr): m = 2,955, 2,877,
3-(2-Chlorobenzoyl)-6-nitro-2(3H)-benzothiazolone
(2a10, C14H7ClN2O4S)
1,710, 1,675, 1,617 cm-1; 1H NMR (CDCl3): d = 1.30 (d,
2CH3), 3.85 (m, 1CH), 8.18–8.23 (m, 2Ar-H), 8.31 (s,
1Ar-H) ppm; 13C NMR (CDCl3): d = 18.71, 36.19,
117.19, 117.60, 122.58, 123.44, 139.46, 144.79, 169.83,
178.32 ppm.
ꢀ
Yield 92%; m.p.: 73–74 °C; IR (KBr): m = 1,719, 1,680,
1
1,618, 1,590 cm-1; H NMR (DMSO-d6): d = 7.24–7.60
(4H, m, 4Ar-H), 8.05 (1H, d, J = 8.05 Hz, 1Ar-H),
8.28–8.30 (2H, m, 2Ar-H) ppm; 13C NMR (DMSO-d6):
123

74
F. Guenadil et al.
d = 116.40, 118.14, 123.03, 123.81, 126.35, 127.50,
130.05, 131.69, 133.67, 135.18, 138.22, 145.10, 168.45,
171.73 ppm.
116.55, 124.31, 125.48, 129.21, 129.44, 129.65, 129.88,
130.50, 133.92, 145.50, 168.08, 168.58 ppm.
6-Bromo-3-(2-chlorobenzoyl)-2(3H)-benzothiazolone
(2b10, C14H7BrClNO2S)
6-Nitro-3-(4-nitrobenzoyl)-2(3H)-benzothiazolone
(2a11, C14H7N3O6S)
ꢀ
Yield 95%; m.p.: 118–119 °C; IR (KBr): m = 1,703, 1,660,
1
Yield 75%; m.p.: 273–275 °C; IR (KBr): m = 1,689, 1,670,
1,618, 1,590 cm-1; H NMR (DMSO-d6): d = 7.28–7.59
ꢀ
1,618 cm-1; 1H NMR (DMSO-d6): d = 7.81–8.10 (3H, m,
3Ar-H), 8.22–8.32 (4H, m, 4Ar-H) ppm; 13C NMR (DMSO-
d6): d = 114.93, 115.56, 121.24, 123.86, 124.87, 126.36,
134.52, 137.79, 142.23, 144.22, 165.86, 168.95 ppm.
(6H, m, 6Ar-H), 8.10 (1H, d, J = 7.88 Hz, 1Ar-H) ppm;
13C NMR (DMSO-d6): d = 116.91, 117.61, 123.09,
123.85, 126.26, 128.45, 128.85, 129.23, 129.86, 131.33,
131.87, 133.35, 165.59, 167.76 ppm.
6-Bromo-3-(2,2-dimethylpropionyl)-2(3H)-benzothiazo-
lone (2b4, C12H12BrNO2S)
6-Bromo-3-(4-nitrobenzoyl)-2(3H)-benzothiazolone
(2b11, C14H7BrN2O4S)
ꢀ
ꢀ
Yield 78%; m.p.: 218–219 °C; IR (KBr): m = 2,934, 1,690,
Yield 71%; m.p.: 219–221 °C; IR (KBr): m = 1,690, 1,660,
1,678, 1,618 cm-1; 1H NMR (DMSO-d6): d = 1.30 (9H, s,
3CH3), 7.36–7.58 (2H, m, 2Ar-H), 7.93 (1H, d,
J = 7.97 Hz, 1Ar-H) ppm; 13C NMR (DMSO-d6): d =
25.24, 42.51, 111.40, 112.18, 122.98, 123.24, 127.40,
133.99, 167.85, 177.59 ppm.
1,604 cm-1; 1H NMR (DMSO-d6): d = 7.42 (2H, m, 2Ar-
H), 7.82–7.98 (3H, m, 3Ar-H), 8.23–8.32 (2H, m, 2Ar-H)
ppm; 13C NMR (DMSO-d6): d = 114.42, 116.62, 118.79,
123.82, 123.89, 128.32, 130.87, 137.49, 142.65, 167.83,
169.81 ppm.
6-Bromo-3-(phenylacetyl)-2(3H)-benzothiazolone
(2b5, C15H10BrNO2S)
3,6-Diacetyl-2(3H)-benzothiazolone (2c1, C11H9NO3S)
ꢀ
Yield 89%; m.p.: 138 °C; IR (KBr): m = 2,973, 1,716,
1
Yield 93%; m.p.: 73–75 °C; IR (KBr): m = 2,935, 1,700,
1,675, 1,618, 1,595 cm-1; H NMR (CDCl3): d = 2.59 (s,
ꢀ
1,675, 1,618 cm-1; 1H NMR (DMSO-d6): d = 3.58 (2H, s,
1CH2), 7.20–7.54 (7H, m, 7Ar-H), 7.97 (1H, d, J = 7.98 Hz,
1Ar-H) ppm; 13C NMR (DMSO-d6): d = 41.83, 114.29,
115.12, 126.19, 127.70, 129.16, 130.34, 130.49, 130.79,
136.16, 136.77, 170.54, 173.80 ppm.
1CH3), 2.76 (s, 1CH3), 7.87 (s, 1Ar-H), 8.04 (d, 1Ar-H),
8.38 (d, 1Ar-H) ppm; 13C NMR (CDCl3): d = 23.98,
24.83, 115.01, 119.51, 125.21, 131.80, 134.67, 138.78,
171.16, 175.62, 196.74 ppm.
6-Acetyl-3-propionyl-2(3H)-benzothiazolone
(2c2, C12H11NO3S)
6-Bromo-3-(3-phenylpropionyl)-2(3H)-benzothiazolone
(2b6, C16H12BrNO2S)
ꢀ
Yield 87%; m.p.: 115 °C; IR (KBr): m = 2,983, 2,924,
Yield 95%; m.p.: 120–122 °C; IR (KBr): m = 2,929, 1,697,
1,725, 1,682, 1,679, 1,617 cm-1 1H NMR (CDCl3):
;
ꢀ
1
1,670, 1,618 cm-1; H NMR (CDCl3): d = 3.04 (2H, t,
d = 1.30 (t, 1CH3), 2.60 (s, 1CH3), 3.12 (q, 1CH2), 7.83
(s, 1Ar-H), 8.03 (d, 1Ar-H), 8.34 (d, 1Ar-H) ppm; 13C NMR
(CDCl3): d = 9.15, 27.12, 33.38, 118.06, 122.66, 123.41,
128.30, 134.80, 138.90, 171.28, 175.63, 196.76 ppm.
2CH2), 3.46 (2H, t, 2CH2), 7.17–7.35 (5H, m, 5Ar-H),
7.40–7.50 (2H, m, 2Ar-H), 7.97 (1H, d, J = 8.00 Hz, 1Ar-
H) ppm; 13C NMR (CDCl3): d = 30.35, 40.63, 118.26,
119.21, 123.31, 124.48, 126.41, 128.55, 130.07, 133.66,
140.11, 142.77, 170.16, 173.13 ppm.
6-Acetyl-3-(2-methylpropionyl)-2(3H)-benzothiazolone
(2c3, C13H13NO3S)
ꢀ
6-Bromo-3-(3-methylbenzoyl)-2(3H)-benzothiazolone
(2b8, C15H10BrNO2S)
Yield 76%; m.p.: 90–91 °C; IR (KBr): m = 2,936, 1,708,
1,685, 1,618 cm-1; 1H NMR (DMSO-d6): d = 1.31 (6H, d,
2CH3), 2.68 (3H, s, 1CH3), 3.83 (1H, m, 1CH), 7.94–8.00
ꢀ
Yield 91%; m.p.: 93–95 °C; IR (KBr): m = 2,924, 1,705,
1,660, 1,604 cm-1; H NMR (CDCl3): d = 2.49 (3H, s,
(2H, m, 2Ar-H), 8.14 (1H, d, J = 7.88 Hz, 1Ar-H) ppm; 13
C
1
1CH3), 7.29–7.69 (6H, m, 6Ar-H), 8.03 (1H, d,
J = 7.99 Hz, 1Ar-H) ppm; 13C NMR (CDCl3): d = 19.78,
116.28, 117.66, 124.51, 125.15, 127.75, 128.64, 129.49,
130.54, 133.84, 138.81, 168.63, 168.76 ppm.
NMR (DMSO-d6): d = 19.88, 26.48, 37.20, 117.89, 123.10,
123.87, 128.59, 135.06, 139.50, 170.48, 179.66, 197.10 ppm.
6-Acetyl-3-(2,2-dimethylpropionyl)-2(3H)-benzothiazolone
(2c4, C14H15NO3S)
ꢀ
6-Bromo-3-(4-methylbenzoyl)-2(3H)-benzothiazolone
(2b9, C15H10BrNO2S)
Yield 78%; m.p.: 179–180 °C; IR (KBr): m = 2,930, 1,713,
1,668, 1,618, 1,597 cm-1; 1H NMR (DMSO-d6): d = 1.38
(9H, s, 3CH3), 2.58 (3H, s, 1CH3), 7.89–7.96(2H, m, 2Ar-H),
8.13 (1H, d, J = 7.98 Hz, 1Ar-H) ppm; 13C NMR (DMSO-
d6): d = 24.86, 25.57, 39.42, 117.79, 123.16, 123.85,
128.49, 135.26, 139.45, 169.87, 173.96, 196.89 ppm.
ꢀ
Yield 90%; m.p.: 156 °C; IR (KBr): m = 2,923, 1,690,
1,678, 1,608 cm-1; 1H NMR (CDCl3): d = 2.50 (s, 1CH3),
7.36 (m, 3Ar-H), 7.54 (d, 1Ar-H), 7.83 (m, 2Ar-H), 8.08 (d,
1Ar-H) ppm; 13C NMR (CDCl3): d = 21.33, 116.17,
123

Design and synthesis of 3-acyl-2(3H)-benzoxazolone and 3-acyl-2(3H)-benzothiazolone derivatives
75
6-Acetyl-3-(phenylacetyl)-2(3H)-benzothiazolone
(2c5, C17H13NO3S)
1CH3), 7.37–7.68 (4H, m, 4Ar-H), 7.76–7.92 (2H, m, 2Ar-
H), 8.11 (1H, d, J = 7.89 Hz, 1Ar-H) ppm; 13C NMR
(DMSO-d6): d = 25.98, 110.19, 114.89, 127.19, 128.33,
129.10, 130.83, 131.94, 132.71, 133.84, 134.58, 135.44,
136.87, 165.84, 167.76, 194.85 ppm.
ꢀ
Yield 83%; m.p.: 72–74 °C; IR (KBr): m = 2,940, 1,700,
1
1,670, 1,618 cm-1; H NMR (CDCl3): d = 2.58 (3H, s,
1CH3), 4.46 (2H, s, 1CH2), 7.23–7.42 (5H, m, 5Ar-H),
7.84–7.92 (2H, m, 2Ar-H), 8.09 (1H, d, J = 7.65 Hz, 1Ar-
H) ppm; 13C NMR (CDCl3): d = 23.96, 36.86, 114.34,
119.59, 120.52, 124.13, 125.19, 126.09, 126.28, 131.72,
135.74, 138.16, 167.87, 169.76, 194.54 ppm.
6-Acetyl-3-(4-nitrobenzoyl)-2(3H)-benzothiazolone
(2c11, C16H10N2O5S)
ꢀ
Yield 70%; m.p.: 117–119 °C; IR (KBr): m = 2,959, 1,718,
1,670, 1,610 cm-1; 1H NMR (DMSO-d6): d = 2.59 (3H, s,
1CH3), 7.81–7.98 (4H, m, 4Ar-H), 8.08 (1H, d,
J = 8.01 Hz, 1Ar-H), 8.20–8.27 (2H, m, 2Ar-H) ppm;
13C NMR (DMSO-d6): d = 24.23, 115.42, 118.75, 123.79,
125.32, 128.39, 130.82, 131.78, 137.59, 139.53, 142.45,
166.23, 168.57, 195.17 ppm.
6-Acetyl-3-(3-phenylpropionyl)-2(3H)-benzothiazolone
(2c6, C18H15NO3S)
ꢀ
Yield 82%; m.p.: 118–119 °C; IR (KBr): m = 2,934, 1,698,
1
1,675, 1,601 cm-1; H NMR (CDCl3): d = 2.60 (3H, s,
1CH3), 3.09 (2H, t, 1CH2), 3.47 (2H, t, 1CH2), 7.20–7.29
(5H, m, 5Ar-H), 7.89–7.99 (2H, m, 2Ar-H), 8.13 (1H, d,
J = 7.89 Hz, 1Ar-H) ppm; 13C NMR (CDCl3): d = 24.04,
27.95, 38.23, 114.37, 119.61, 120.32, 124.03, 125.21,
126.12, 126.18, 131.81, 135.86, 137.60, 168.57, 170.86,
193.64 ppm.
3-Acetyl-6-propionyl-2(3H)-benzoxazolone
(3c1, C12H11NO4)
ꢀ
Yield 86%; m.p.: 180–182 °C; IR (KBr): m = 2,938, 1,785,
1,732, 1,678, 1,598 cm-1; 1H NMR (DMSO-d6): d = 1.24
(3H, t, 1CH3), 2.80 (3H, s, 1CH3), 2.98 (2H, q, 1CH2), 7.80
(1H, s, 1Ar-H), 7.90 (1H, d, J = 7.98 Hz, 1Ar-H), 8.14
(1H, d, J = 7.98 Hz, 1Ar-H) ppm; 13C NMR (DMSO-d6):
d = 8.18, 24.97, 31.85, 109.29, 115.56, 124.49, 131.13,
134.43, 142.35, 151.36, 169.26, 198.67 ppm.
6-Acetyl-3-benzoyl-2(3H)-benzothiazolone
(2c7, C16H11NO3S)
ꢀ
Yield 69%; m.p.: 68–70 °C; IR (KBr): m = 2,934, 1,710,
1
1,685, 1,600 cm-1; H NMR (CDCl3): d = 2.62 (3H, s,
1CH3), 7.43–7.79 (5H, m, 5Ar-H), 7.81–7.98 (2H, m, 2Ar-
H), 8.09 (1H, d, J = 7.88 Hz, 1Ar-H) ppm; 13C NMR
(CDCl3): d = 23.97, 107.85, 112.46, 123.67, 126.66,
127.13, 128.00, 128.35, 129.85, 131.39, 132.31, 169.78,
170.16, 194.35 ppm.
3,6-Dipropionyl-2(3H)-benzoxazolone
(3c2, C13H13NO4)
Yield 89%; m.p.: 174 °C; IR (KBr): ꢀm = 2,977, 2,939,
1,802, 1,730, 1,678, 1,618, 1,601 cm-1; 1H NMR (CDCl3):
d = 1.25 (t, 1CH3), 1.35 (t, 1CH3), 3.05 (q, 1CH2), 3.85 (q,
1CH2), 7.80 (s, 1Ar-H), 7.90 (d, 1Ar-H), 8.18 (d, 1Ar-H)
ppm; 13C NMR (CDCl3): d = 7.93, 8.20, 30.58, 31.85,
109.27, 115.56, 125.48, 131.67, 134.29, 142.81, 150.73,
173.24, 198.68 ppm.
6-Acetyl-3-(3-methylbenzoyl)-2(3H)-benzothiazolone
(2c8, C17H13NO3S)
ꢀ
Yield 84%; m.p.: 79–80 °C; IR (KBr): m = 2,929, 1,698,
1,672, 1,618, 1,604 cm-1 1H NMR (CDCl3): d = 2.50
;
(3H, s, 1CH3), 2.61 (3H, s, 1CH3), 7.21–7.38 (4H, m, 4Ar-
H), 7.80–7.90 (2H, m, 2Ar-H), 8.06 (1H, d, J = 7.89 Hz,
1Ar-H) ppm; 13C NMR (CDCl3): d = 20.05, 25.19,
110.73, 112.69, 124.45, 127.52, 127.63, 128.07, 129.48,
133.32, 134.10, 137.89, 166.57, 170.91, 194.25 ppm.
3-(2-Methylpropionyl)-6-propionyl-2(3H)-benzoxazolone
(3c3, C14H15NO4)
ꢀ
Yield 88%; m.p.: 115 °C; IR (KBr): m = 2,975, 2,939,
1,809, 1,725, 1,683, 1,618, 1,599 cm-1; 1H NMR (CDCl3):
d = 1.25 (t, 1CH3), 1.35 (d, 2CH3), 3.05 (q, 1CH2), 3.85
(m, 1CH), 7.80 (s, 1Ar-H), 7.90 (d, 1Ar-H), 8.18 (d, 1Ar-
H) ppm; 13C NMR (CDCl3): d = 8.20, 18.68, 31.85, 34.19,
109.20, 115.80, 125.42, 131.68, 134.30, 142.80, 150.72,
176.82, 198.68 ppm.
6-Acetyl-3-(4-methylbenzoyl)-2(3H)-benzothiazolone
(2c9, C17H13NO3S)
ꢀ
Yield 91%; m.p.: 85–86 °C; IR (KBr): m = 2,924, 1,712,
1
1,677, 1,608 cm-1; H NMR (CDCl3): d = 2.47 (3H, s,
1CH3), 2.61 (3H, s, 1CH3), 7.30–7.68 (4H, m, 4Ar-H),
7.77–7.96 (2H, m, 2Ar-H), 8.05 (1H, d, J = 8.10 Hz, 1Ar-
H) ppm; 13C NMR (CDCl3): d = 21.35, 26.48, 114.30,
122.77, 126.74, 127.52, 129.59, 129.67, 130.15, 130.64,
145.58, 146.24, 162.87, 169.89, 194.42 ppm.
3-(2,2-Dimethylpropionyl)-6-propionyl-2(3H)-benzoxazo-
lone (3c4, C15H17NO4)
ꢀ
Yield 79%; m.p.: 111–113 °C; IR (KBr): m = 2,930, 1,775,
1,720, 1,670, 1,618, 1,598 cm-1 1H NMR (CDCl3):
;
d = 1.23 (3H, t, 1CH3), 1.50 (9H, s, 3CH3), 3.00 (2H, q,
1CH2), 7.79 (1H, s, 1Ar-H), 7.88 (1H, d, J = 7.88 Hz, 1Ar-
H), 8.14 (1H, d, J = 7.88 Hz, 1Ar-H) ppm; 13C NMR
(CDCl3): d = 8.21, 26.17, 31.83, 37.98, 109.17, 115.72,
6-Acetyl-3-(2-chlorobenzoyl)-2(3H)-benzothiazolone
(2c10, C16H10ClNO3S)
ꢀ
Yield 89%; m.p.: 89–90 °C; IR (KBr): m = 2,934, 1,719,
1,675, 1,619 cm-1; 1H NMR (DMSO-d6): d = 2.54 (3H, s,
123

76
F. Guenadil et al.
125.11, 132.94, 133.97, 142.22, 150.21, 178.17, 198.73
ppm.
3-(2-Chlorobenzoyl)-6-propionyl-2(3H)-benzoxazolone
(3c10, C17H12ClNO4)
ꢀ
Yield 92%; m.p.: 82–84 °C; IR (KBr): m = 2,927, 1,781,
1,718, 1,670, 1,618 cm-1; 1H NMR (DMSO-d6): d = 1.21
(3H, t, 1CH3), 2.93 (2H, q, 1CH2), 7.30–7.93 (6H, m, 6Ar-
H), 8.03 (1H, s, 1Ar-H) ppm; 13C NMR (DMSO-d6):
d = 8.20, 31.89, 109.53, 115.13, 125.59, 126.61, 129.78,
130.82, 131.39, 132.61, 134.74, 142.73, 149.79, 165.49,
198.67 ppm.
3-(Phenylacetyl)-6-propionyl-2(3H)-benzoxazolone
(3c5, C18H15NO4)
ꢀ
Yield 89%; m.p.: 101–102 °C; IR (KBr): m = 2,943, 1,785,
1,725, 1,662, 1,618 cm-1; 1H NMR (DMSO-d6): d = 1.24
(3H, t, 1CH3), 2.95 (2H, q, 1CH2), 4.43 (2H, s, 1CH2),
7.19–7.51 (5H, m, 5Ar-H), 7.81 (1H, s, 1Ar-H), 8.00–8.20
(2H, m, 2Ar-H) ppm; 13C NMR (DMSO-d6): d = 8.19,
30.81, 42.81, 109.95, 111.18, 116.26, 123.28, 123.37,
125.40, 126.74, 128.76, 131.24, 141.10, 151.43, 170.43,
198.71 ppm.
3-(4-Nitrobenzoyl)-6-propionyl-2(3H)-benzoxazolone
(3c11, C17H12N2O6)
ꢀ
Yield 75%; m.p.: 153–155 °C; IR (KBr): m = 2,938, 1,766,
1,710, 1,680, 1,618 cm-1; 1H NMR (DMSO-d6): d = 1.21
(3H, t, 1CH3), 2.98 (2H, q, 1CH2), 7.80–7.98 (4H, m, 4Ar-
H), 8.09 (1H, d, J = 8.02 Hz, 1Ar-H), 8.21–8.29 (2H, m,
2Ar-H) ppm; 13C NMR (DMSO-d6): d = 8.13, 31.49,
108.38, 121.54, 123.56, 124.35, 128.42, 131.69, 136.18,
139.43, 142.89, 147.98, 153.24, 166.36, 194.27 ppm.
3-(3-Phenylpropionyl)-6-propionyl-2(3H)-benzoxazolone
(3c6, C19H17NO4)
ꢀ
Yield 88%; m.p.: 177–179 °C; IR (KBr): m = 2,939, 1,785,
1,729, 1,677, 1,618 cm-1 1H NMR (CDCl3): d = 1.23
;
(3H, t, 1CH3), 2.93 (2H, q, 1CH2), 3.13 (2H, t, 1CH2), 3.44
(2H, t, 1CH2), 7.19–7.36 (5H, m, 5Ar-H), 7.80 (1H, s, 1Ar-
H), 8.00–8.15 (2H, m, 2Ar-H) ppm; 13C NMR (CDCl3):
d = 8.00, 29.62, 31.67, 38.29, 109.10, 115.42, 125.28,
126.34, 128.36, 128.45, 131.04, 134.21, 139.64, 142.25,
150.87, 171.98, 198.48 ppm.
3-Acetyl-6-propionyl-2(3H)-benzothiazolone
(4c1, C12H11NO3S)
ꢀ
Yield 92%; m.p.: 119–120 °C; IR (KBr): m = 2,942, 1,717,
1,670, 1,618 cm-1; 1H NMR (DMSO-d6): d = 1.29 (3H, t,
1CH3), 2.76 (3H, s, 1CH3), 2.98 (2H, q, 2CH2), 7.90–7.98
(2H, m, 2Ar-H), 8.03 (1H, d, J = 7.97 Hz, 1Ar-H) ppm;
13C NMR (DMSO-d6): d = 8.04, 27.20, 31.67, 117.37,
121.56, 122.44, 127.41, 133.86, 140.56, 170.18, 173.25,
194.35 ppm.
3-Benzoyl-6-propionyl-2(3H)-benzoxazolone
(3c7, C17H13NO4)
ꢀ
Yield 83%; m.p.: 118–120 °C; IR (KBr): m = 2,928, 1,784,
1,698, 1,663, 1,617 cm-1; 1H NMR (DMSO-d6): d = 1.19
(3H, t, 1CH3), 3.03 (2H, q, 2CH2), 7.39–7.61 (5H, m, 5Ar-
H), 7.79–7.96 (2H, m, 2Ar-H), 8.15 (1H, d, J = 8.02 Hz,
1Ar-H) ppm; 13C NMR (DMSO-d6): d = 9.09, 31.28,
109.11, 114.48, 124.64, 126.32, 128.43, 128.45, 129.41,
133.19, 135.68, 142.40, 150.40, 167.56, 198.87 ppm.
3-(2-Methylpropionyl)-6-propionyl-2(3H)-benzothiazolone
(4c3, C14H15NO3S)
ꢀ
Yield 84%; m.p.: 119 °C; IR (KBr): m = 2,977, 2,936,
2,910, 1,729, 1,682, 1,677, 1,618, 1,592 cm-1; H NMR
1
(CDCl3): d = 1.20–1.40 (m, 3CH3), 2.96 (q, 1CH2), 3.87
(m, 1CH), 7.93 (s, 1Ar-H), 8.04 (d, 1Ar-H), 8.16 (d, 1Ar-
H) ppm; 13C NMR (CDCl3): d = 8.01, 18.69, 31.56, 36.00,
116.70, 121.68, 122.65, 126.95, 133.67, 138.14, 170.01,
173.23, 198.29 ppm.
3-(3-Methylbenzoyl)-6-propionyl-2(3H)-benzoxazolone
(3c8, C18H15NO4)
ꢀ
Yield 84%; m.p.: 87–89 °C; IR (KBr): m = 2,925, 1,787,
1
1,703, 1,675, 1,603, 1,590 cm-1; H NMR (DMSO-d6):
d = 1.25 (3H, t, 1CH3), 2.47 (3H, s, 1CH3), 2.97 (2H, q,
1CH2), 7.19–7.40 (2H, m, 2Ar-H), 7.71–7.92 (4H, m, 4Ar-
H), 8.12 (1H, s, 1Ar-H) ppm; 13C NMR (DMSO-d6):
d = 7.79, 21.43, 30.98, 109.14, 114.42, 124.22, 128.79,
129.85, 130.24, 133.69, 134.27, 139.44, 142.41, 150.23,
166.74, 198.34 ppm.
3-(2,2-Dimethylpropionyl)-6-propionyl-2(3H)-benzo-
thiazolone (4c4, C15H17NO3S)
ꢀ
Yield 83%; m.p.: 103–104 °C; IR (KBr): m = 2,940, 1,704,
1,676, 1,618, 1,599 cm-1; 1H NMR (DMSO-d6): d = 1.17
(9H, m, 3CH3), 1.38 (3H, t, 1CH3), 2.96 (2H, q, 1CH2),
7.80–7.95 (2H, m, 2Ar-H), 8.12 (1H, d, J = 7.78 Hz, 1Ar-
H) ppm; 13C NMR (DMSO-d6): d = 5.92, 24.67, 28.61,
37.83, 108.89, 114.97, 120.79, 124.46, 129.63, 138.12,
168.15, 175.18, 197.39 ppm.
3-(4-Methylbenzoyl)-6-propionyl-2(3H)-benzoxazolone
(3c9, C18H15NO4)
ꢀ
Yield 93%; m.p.: 160–162 °C; IR (KBr): m = 2,920, 1,772,
1,695, 1,670, 1,610 cm-1; 1H NMR (CDCl3): d = 1.26 (3H,
t, 1CH3), 2.46 (3H, s, 1CH3), 2.98 (2H, q, 1CH2), 7.20–7.39
(2H, m, 2Ar-H), 7.70–7.90 (4H, m, 4Ar-H), 8.09 (1H, s, 1Ar-
H) ppm; 13C NMR (CDCl3): d = 7.84, 21.46, 31.47, 109.16,
114.45, 124.23, 128.83, 129.87, 130.26, 133.79, 134.28,
139.54, 142.46, 150.25, 166.84, 198.36 ppm.
3-(Phenylacetyl)-6-propionyl-2(3H)-benzothiazolone
(4c5, C18H15NO3S)
ꢀ
Yield 90%; m.p.: 164–166 °C; IR (KBr): m = 2,942, 1,701,
1,661, 1,592 cm-1; 1H NMR (DMSO-d6): d = 1.27 (3H, t,
1CH3), 2.89 (2H, q, 2CH2), 4.46 (2H, s, 1CH2), 7.21–7.49
123

Design and synthesis of 3-acyl-2(3H)-benzoxazolone and 3-acyl-2(3H)-benzothiazolone derivatives
77
(5H, m, 5Ar-H), 7.81–8.00 (1H, m, 1Ar-H), 8.14 (1H, s, 1Ar-
H) ppm; 13C NMR (DMSO-d6): d = 7.95, 28.58, 41.98,
117.58, 121.63, 122.87, 125.98, 127.29, 128.23, 128.72,
134.34, 137.56, 139.76, 169.57, 172.39, 198.18 ppm.
3-(4-Nitrobenzoyl)-6-propionyl-2(3H)-benzothiazolone
(4c11, C17H12N2O5S)
ꢀ
Yield 57%; m.p.: 138–140 °C; IR (KBr): m = 2,939, 1,681,
1,673, 1,618, 1,602 cm-1; 1H NMR (DMSO-d6): d = 1.22
(3H, t, 1CH3), 2.97 (2H, q, 1CH2), 7.83–7.99 (4H, m, 4Ar-
H), 8.12 (1H, d, J = 7.85 Hz, 1Ar-H), 8.20–8.28 (2H, m,
2Ar-H) ppm; 13C NMR (DMSO-d6): d = 8.32, 31.38,
116.32, 119.45, 123.69, 124.93, 128.29, 130.85, 131.68,
137.57, 139.73, 142.58, 166.32, 169.67, 194.85 ppm.
3-(3-Phenylpropionyl)-6-propionyl-2(3H)-benzothiazolone
(4c6, C19H17NO3S)
ꢀ
Yield 91%; m.p.: 100–103 °C; IR (KBr): m = 2,939, 1,699,
1
1,674, 1,618 cm-1; H NMR (CDCl3): d = 1.24 (3H, t,
CH3), 2.93 (2H, q, CH2), 3.10 (2H, t, CH2), 3.47 (2H, t,
1CH2), 7.20–7.40 (5H, m, 5Ar-H), 7.86–7.98 (2H, m, 2Ar-
H), 8.14 (1H, m, 1Ar-H) ppm; 13C NMR (CDCl3):
d = 8.18, 30.42, 31.76, 40.71, 117.42, 121.32, 122.74,
126.47, 127.19, 128.37, 128.62, 134.16, 137.36, 140.06,
169.85, 173.29, 198.27 ppm.
6-Benzoyl-3-propionyl-2(3H)-benzoxazolone
(5c2, C17H13NO4)
ꢀ
Yield 82%; m.p.: 189–191 °C; IR (KBr): m = 2,947, 1,800,
1,732, 1,645, 1,597 cm-1; 1H NMR (DMSO-d6): d = 1.30
(3H, t, 1CH3), 3.20 (2H, q, 1CH2), 7.39–7.82 (7H, m, 7Ar-
H), 8.16 (1H, d, J = 7.94 Hz, 1Ar-H) ppm; 13C NMR
(DMSO-d6): d = 7.94, 30.59, 111.71, 115.34, 127.78,
128.90, 129.92, 131.10, 132.75, 134.76, 137.13, 142.16,
151.12, 173.25, 194.75 ppm.
3-Benzoyl-6-propionyl-2(3H)-benzothiazolone
(4c7, C17H13NO3S)
ꢀ
Yield 78%; m.p.: 19–21 °C; IR (KBr): m = 2,934, 1,698,
1,670, 1,617 cm-1; 1H NMR (DMSO-d6): d = 1.19 (3H, t,
CH3), 3.02 (2H, q, CH2), 7.36–7.62 (5H, m, Ar–H),
7.78–7.96 (2H, m, Ar–H), 8.15 (1H, d, J = 7.99 Hz, Ar–H)
ppm; 13C NMR (DMSO-d6): d = 7.27, 30.78, 113.23,
121.16, 126.19, 127.90, 128.16, 129.25, 131.20, 132.77,
133.69, 137.19, 167.62, 168.22, 197.79 ppm.
6-Benzoyl-3-(2-methylpropionyl)-2(3H)-benzoxazolone
(5c3, C18H15NO4)
ꢀ
Yield 85%; m.p.: 137 °C; IR (KBr): m = 2,936, 1,790,
1,724, 1,652, 1,597, 1,578 cm-1
;
1H NMR (CDCl3):
d = 1.48 (d, 2CH3), 3.86 (m, 1CH), 7.36–7.48 (m, 2Ar-
H), 7.54 (d, 1Ar-H), 7.76–7.68 (m, 4Ar-H), 8.14 (d, 1Ar-H)
ppm; 13C NMR (CDCl3): d = 18.57, 34.09, 111.13,
115.46, 127.62, 128.38, 129.81, 131.32, 132.63, 133.44,
134.62, 137.03, 142.08, 150.58, 176.72, 194.68 ppm.
3-(3-Methylbenzoyl)-6-propionyl-2(3H)-benzothiazolone
(4c8, C18H15NO3S)
Yield 86%; m.p.: 39–41 °C; IR (KBr): ꢀm = 2,925, 1,714,
1,675, 1,618 cm-1; 1H NMR (DMSO-d6): d = 1.23 (3H, t,
1CH3), 2.42 (3H, s, 1CH3), 2.95 (2H, q, 1CH2), 7.41–7.63
(4H, m, 4Ar-H), 7.82–7.98 (2H, m, 2Ar-H), 8.10 (1H, s, 1Ar-
H) ppm; 13C NMR (DMSO-d6): d = 8.90, 22.61, 32.40,
114.87, 123.17, 124.63, 126.91, 127.76, 130.25, 132.79,
134.26, 139.39, 142.32, 163.23, 169.82, 197.84 ppm.
6-Benzoyl-3-(2,2-dimethylpropionyl)-2(3H)-benzoxazolone
(5c4, C19H17NO4)
ꢀ
Yield 73%; m.p.: 103–105 °C; IR (KBr): m = 2,936, 1,790,
1,725, 1,652, 1,598 cm-1; 1H NMR (DMSO-d6): d = 1.50
(9H, s, 3CH3), 7.40–7.85 (7H, s, 7Ar-H), 7.98 (1H, d,
J = 8.02 Hz, 1Ar-H) ppm; 13C NMR (DMSO-d6):
d = 26.19, 42.95, 109.37, 111.38, 111.49, 115.82,
127.70, 129.85, 132.52, 137.52, 142.45, 152.37, 167.72,
195.17 ppm.
3-(4-Methylbenzoyl)-6-propionyl-2(3H)-benzothiazolone
(4c9, C18H15NO3S)
ꢀ
Yield 89%; m.p.: 101–103 °C; IR (KBr): m = 2,922, 1,712,
1
1,675, 1,609 cm-1; H NMR (CDCl3): d = 1.26 (3H, t,
1CH3), 2.48 (3H, s, 1CH3), 2.99 (2H, q, 1CH2), 7.40–7.62
(4H, m, 4Ar-H), 7.80–7.96 (2H, m, 2Ar-H), 8.11 (1H, s,
1Ar-H) ppm; 13C NMR (CDCl3): d = 8.34, 21.28, 31.74,
114.29, 122.64, 126.82, 127.56, 128.14, 130.69, 132.13,
133.72, 137.96, 138.62, 162.77, 170.14, 198.64 ppm.
6-Benzoyl-3-(phenylacetyl)-2(3H)-benzoxazolone
(5c5, C22H15NO4)
ꢀ
Yield 85%; m.p.: 133–136 °C; IR (KBr): m = 2,914, 1,753,
1
1,700, 1,651, 1,615, 1,598 cm-1; H NMR (DMSO-d6):
d = 4.49 (2H, s, 1CH2), 7.30–7.80 (12H, m, 12Ar-H), 8.14
(1H, s, 1Ar-H) ppm; 13C NMR (DMSO-d6): d = 42.77,
111.41, 115.32, 127.59, 127.69, 128.38, 128.68, 129.69,
129.79, 130.95, 132.01, 132.64, 134.83, 136.95, 142.03,
150.88, 170.33, 194.54 ppm.
3-(2-Chlorobenzoyl)-6-propionyl-2(3H)-benzothiazolone
(4c10, C17H12ClNO3S)
ꢀ
Yield 90%; m.p.: 85–87 °C; IR (KBr): m = 2,937, 1,701,
1,679, 1,619 cm-1; 1H NMR (DMSO-d6): d = 1.24 (3H, t,
1CH3), 2.96 (2H, q, 1CH2), 7.39–7.93 (6H, m, 6Ar-H),
8.16 (1H, s, 1Ar-H) ppm; 13C NMR (DMSO-d6): d = 8.12,
31.70, 116.00, 122.15, 126.88, 127.34, 127.90, 129.90,
130.96, 132.65, 132.94, 134.24, 135.08, 137.69, 166.66,
169.19, 198.70 ppm.
6-Benzoyl-3-(3-phenylpropionyl)-2(3H)-benzoxazolone
(5c6, C23H17NO4)
ꢀ
Yield 87%; m.p.: 139–140 °C; IR (KBr): m = 2,931, 1,775,
1,724, 1,650, 1,597 cm-1 1H NMR (CDCl3): d = 3.11
(2H, t, 1CH2), 3.45 (2H, t, 1CH2), 7.20–7.38 (5H, m, 5Ar-
;
123

78
F. Guenadil et al.
H), 7.60–7.80 (7H, m, 7Ar-H), 8.14 (1H, s, 1Ar-H) ppm;
13C NMR (DMSO-d6): d = 29.85, 38.51, 111.17, 115.43,
126.59, 127.80, 128.34, 128.67, 129.96, 131.02, 132.80,
134.69, 137.14, 139.85, 142.17, 151.66, 171.24, 194.24
ppm.
6-Benzoyl-3-(2-methylpropionyl)-2(3H)-benzoxazolone
(6c3, C18H15NO3S)
Yield 70%; m.p.: 110–111 °C; IR (KBr): m = 2,934, 1,698,
1,670, 1,648, 1,618, 1,595 cm-1 1H NMR (CDCl3):
ꢀ
;
d = 1.28 (6H, m, 2CH3), 3.87 (1H, m, 1CH), 7.43–7.83
(7H, m, 7Ar-H), 8.15 (1H, d, J = 8.01 Hz, 1Ar-H) ppm;
13C NMR (CDCl3): d = 18.86, 36.19, 116.60, 123.83,
127.59, 128.47, 129.32, 129.91, 132.70, 134.20, 137.26,
139.86, 169.98, 172.19, 196.37 ppm.
6-Benzoyl-3-(3-methylbenzoyl)-2(3H)-benzoxazolone
(5c8, C22H15NO4)
ꢀ
Yield 82%; m.p.: 164–166 °C; IR (KBr): m = 2,917, 1,754,
1,705, 1,640, 1,594 cm-1 1H NMR (CDCl3): d = 2.43
;
(3H, s, 1CH3), 7.30–7.50 (4H, m, 4Ar-H), 7.62–7.85 (7H,
m, 7Ar-H), 7.94 (1H, s, 1Ar-H) ppm; 13C NMR (CDCl3):
d = 21.32, 111.53, 114.28, 126.62, 127.65, 128.35, 128.51,
129.95, 130.18, 131.79, 132.76, 134.74, 137.18, 138.50,
142.68, 150.72, 167.63, 194.76 ppm.
6-Benzoyl-3-(2,2-dimethylpropionyl)-2(3H)-benzothiazo-
lone (6c4, C19H17NO3S)
ꢀ
Yield 72%; m.p.: 191–193 °C; IR (KBr): m = 2,939, 1,699,
1,684, 1,640, 1,619 cm-1; 1H NMR (DMSO-d6): d = 1.48
(9H, s, 3CH3), 7.42–7.85 (7H, m, 7Ar-H), 8.09 (1H, d,
J = 7.98 Hz, 1Ar-H) ppm; 13C NMR (DMSO-d6):
d = 25.98, 42.83, 111.14, 123.80, 124.81, 128.49, 128.94,
129.41, 131.32, 132.31, 137.36, 140.20, 168.78, 170.63,
194.42 ppm.
6-Benzoyl-3-(4-methylbenzoyl)-2(3H)-benzoxazolone
(5c9, C22H15NO4)
ꢀ
Yield 89%; m.p.: 185–187 °C; IR (KBr): m = 2,921, 1,785,
1,712, 1,645, 1,609 cm-1 1H NMR (CDCl3): d = 2.42
;
6-Benzoyl-3-(phenylacetyl)-2(3H)-benzothiazolone
(6c5, C22H15NO3S)
(3H, s, 1CH3), 7.29–7.49 (4H, m, 4Ar-H), 7.61–7.83 (7H,
m, 7Ar-H), 7.93 (1H, d, J = 7.98 Hz, 1Ar-H) ppm; 13C
NMR (CDCl3): d = 21.11, 110.83, 113.44, 126.84, 127.72,
128.11, 128.45, 129.16, 129.31, 131.95, 132.35, 134.68,
137.20, 138.52, 142.58, 151.12, 167.60, 194.69 ppm.
ꢀ
Yield 90%; m.p.: 53–55 °C; IR (KBr): m = 2,926, 1,699,
1
1,670, 1,647, 1,618, 1,598 cm-1; H NMR (DMSO-d6):
d = 4.46 (2H, s, 1CH2), 7.14–7.39 (4H, m, 4Ar-H),
7.43–7.80 (7H, m, 7Ar-H), 7.98 (1H, s, 1Ar-H) ppm; 13C
NMR (DMSO-d6): d = 41.14, 116.39, 120.93, 122.68,
124.37, 127.34, 128.44, 128.75, 129.32, 129.39, 130.18,
132.30, 133.49, 136.75, 137.34, 139.92, 169.34, 171.23,
194.53 ppm.
6-Benzoyl-3-(2-chlorobenzoyl)-2(3H)-benzoxazolone
(5c10, C21H12ClNO4)
Yield 85%; m.p.: 182–184 °C; IR (KBr): ꢀm = 1,775, 1,703,
1,651, 1,597 cm-1 1H NMR (CDCl3): d = 7.34–7.85
;
(11H, m, 11Ar-H), 7.96 (1H, s, 1Ar-H) ppm; 13C NMR
(CDCl3): d = 111.60, 114.24, 127.25, 127.85, 128.54,
128.61, 129.97, 130.04, 131.16, 132.53, 132.91, 133.13,
135.31, 142.62, 151.24, 165.64, 194.38 ppm.
6-Benzoyl-3-(3-phenylpropionyl)-2(3H)-benzothiazolone
(6c6, C23H17NO3S)
ꢀ
Yield 91%; m.p.: 163–165 °C; IR (KBr): m = 2,929, 1,699,
1,670, 1,640, 1,590 cm-1; 1H NMR (CDCl3): d = 3.09 (2H,
t, 1CH2), 3.36 (2H, t, 1CH2), 7.12–7.37 (5H, m, 5Ar-H),
7.43–7.83 (7H, m, 7Ar-H), 7.98 (1H, s, 1Ar-H) ppm; 13C
NMR (DMSO-d6): d = 29.67, 35.21, 111.43, 116.11,
124.32, 124.64, 125.93, 128.19, 128.37, 129.43, 131.12,
132.68, 133.96, 137.21, 140.16, 141.07, 170.16, 171.32,
194.35 ppm.
6-Benzoyl-3-(4-nitrobenzoyl)-2(3H)-benzoxazolone
(5c11, C21H12N2O6)
ꢀ
Yield 68%; m.p.: 155–158 °C; IR (KBr): m = 1,760,
1,704, 1,650, 1,617 cm-1 1H NMR (DMSO-d6):
;
d = 7.42–7.84 (7H, m, 7Ar-H), 8.10–8.24 (3H, m, 3Ar-
H), 8.31 (2H, m, 2Ar-H) ppm; 13C NMR (DMSO-d6):
d = 111.63, 114.68, 123.80, 125.59, 128.65, 128.98,
129.58, 131.48, 132.04, 132.58, 134.24, 136.85, 142.73,
150.92, 167.29, 194.27 ppm.
3,6-Dibenzoyl-2(3H)-benzothiazolone
(6c7, C21H13NO3S)
ꢀ
Yield 72%; m.p.: 65–67 °C; IR (KBr): m = 1,694, 1,660,
1,647, 1,597 cm-1; 1H NMR (CDCl3): d = 7.39–7.86 (12H,
m, 12Ar-H), 7.96 (1H, d, J = 7.77 Hz, 1Ar-H) ppm; 13C
NMR (CDCl3): d = 112.03, 114.92, 125.49, 128.74,
129.03, 129.47, 129.80, 131.19, 131.49, 132.81, 133.80,
134.38, 136.07, 138.67, 168.14, 169.34, 194.42 ppm.
6-Benzoyl-3-propionyl-2(3H)-benzothiazolone
(6c2, C17H13NO3S)
ꢀ
Yield 76%; m.p.: 104–106 °C; IR (KBr): m = 2,946, 1,698,
1,660, 1,645, 1,597 cm-1; 1H NMR (DMSO-d6): d = 1.32
(3H, t, 1CH3), 3.16 (2H, q, 1CH2), 7.43–7.82 (7H, m, 7Ar-
H), 8.13 (1H, d, J = 7.88 Hz, 1Ar-H) ppm; 13C NMR
(DMSO-d6): d = 8.18, 30.42, 117.42, 121.32, 122.74,
126.47, 127.19, 128.37, 128.62, 134.16, 137.36, 140.06,
169.85, 173.29, 198.27 ppm.
6-Benzoyl-3-(3-methylbenzoyl)-2(3H)-benzothiazolone
(6c8, C22H15NO3S)
ꢀ
Yield 71%; m.p.: 60–62 °C; IR (KBr): m = 2,923, 1,717,
1,680, 1,639, 1,605 cm-1 1H NMR (CDCl3): d = 2.41
;
123

Design and synthesis of 3-acyl-2(3H)-benzoxazolone and 3-acyl-2(3H)-benzothiazolone derivatives
79
8. Bonte JP, Lesieur D, Plat M, Cazin JC, Cazin M, Lespagnol C
(1974) Eur J Med Chem 9:491
9. Mairesse G, Boivin JC, Thomas DJ, Bermann MC, Bonte JP,
Lesieur D (1984) Acta Crystallogr C 40:1019
10. Follet C, Boivin JC, Bonte JP, Lesieur D (1991) Acta Crystallogr
C 47:882
(3H, s, 1CH3), 7.32–7.49 (4H, m, 4Ar-H), 7.58–7.93 (7H,
m, 7Ar-H), 7.95 (1H, s, 1Ar-H) ppm; 13C NMR (CDCl3):
d = 18.85, 112.04, 125.48, 126.69, 127.72, 128.55, 128.89,
129.87, 130.28, 131.67, 132.65, 133.50, 135.92, 136.38,
138.98, 166.75, 169.52, 194.66 ppm.
11. Diouf O, Depreux P, Lesieur D, Poupaert JH, Caignard DH
(1995) Heterocycles 41:1219
12. Ucar H, Van derpoorten K, Depovere P, Lesieur D, Isa M,
Masereel B, Delarge J, Poupaert JH (1998) Tetrahedron
54:1763
13. Cotelle N, Cotelle P, Lesieur D (1989) Synth Comm 19:3259
14. Ucar H, Van derpoorten K, Cacciaguerra S, Spampinato S, Sta-
bles JP, Depovere P, Isa M, Masereel B, Delarge J, Poupaert JH
(1998) Med Chem 41:3102
15. Ishida S, Hashida Y, Shizuka H, Matsui K (1979) Bull Chem Soc
Jpn 52:1135
16. Ucar H, Van derpoorten K, Kanyonyo M, Lambert D, Isa M,
Lesieur D, Poupaert JH (1996) Bull Soc Chim Belg 105:773
17. Ouyang X, Han J, Kang R, Zhen X (2001) Cuihua Xuebao 22:487
18. Zheng E, Zheng X (2006) J Nat Gas Chem 15:70
19. Yusuf MM, Imai H, Hirashima H (2001) J Non-Cryst Solids
285:90
20. Belciug MP, Modro AM, Modro TA, Wessels PL (1996) Bull
Magn Reson 18:135
21. Belciug MP, Modro Agnes M, Modro Tomasza A, Wessels
Philippus L (1995) J Phys Org Chem 8:605
6-Benzoyl-3-(4-methylbenzoyl)-2(3H)-benzothiazolone
(6c9, C22H15NO3S)
ꢀ
Yield 79%; m.p.: 65–66 °C; IR (KBr): m = 2,923, 1,713,
1,682, 1,638, 1,610 cm-1 1H NMR (CDCl3): d = 2.43
;
(3H, s, 1CH3), 7.28–7.47 (4H, m, 4Ar-H), 7.59–7.82 (7H,
m, 7Ar-H), 7.99 (1H, d, J = 7.78 Hz, 1Ar-H) ppm; 13C
NMR (CDCl3): d = 19.76, 112.24, 124.15, 126.77, 127.82,
128.36, 128.85, 129.85, 130.24, 131.64, 132.59, 133.49,
135.72, 136.82, 138.87, 167.59, 170.15, 194.75 ppm.
6-Benzoyl-3-(2-chlorobenzoyl)-2(3H)-benzothiazolone
(6c10, C21H12ClNO3S)
ꢀ
Yield 89%; m.p.: 119–120 °C; IR (KBr): m = 1,703, 1,675,
1,652, 1,614, 1,595 cm-1 1H NMR (CDCl3): d =
;
7.33–7.84 (11H, m, 1Ar-H), 7.93 (1H, s, 1Ar-H) ppm; 13C
NMR (CDCl3): d = 115.60, 122.72, 124.02, 126.61,
127.85, 128.73, 129.65, 129.84, 130.58, 131.54, 132.64,
133.91, 135.72, 136.99, 139.24, 166.67, 168.78, 194.48
ppm.
22. Lespagnol Ch (1955) Bull Soc Pharmacie Lille 71
23. Baine NH, Clark Jr WM, Eldridge A (2000) USA Patent WO
2000012468
24. Igor P, Marko Z, Stojan S (2006) Tetrahedron Lett 47:4707
25. Aichaoui H, Poupaert JH, Lesieur D, Henichart JP (1991) Tet-
rahedron 47:6649
6-Benzoyl-3-(4-nitrobenzoyl)-2(3H)-benzothiazolone
(6c11, C21H12N2O5S)
26. Aichaoui H, Lesieur D, Henichart JP (1992) J Heterocycl Chem
29:171
27. Yous S, Poupaert JH, Lesieur I, Depreux P, Lesieur D (1994) J
Org Chem 59:1574
28. Carato P, Yous S, Sellier D, Poupaert JH, Lebegue N, Berthelot P
(2004) Tetrahedron 60:10321
29. Ucar H, Van derpoorten K, Cacciaguerra S, Spampinato S,
Stables JP, Depovere P, Isa M, Masereel B, Delarge J, Poupaert
JH (1998) Med Chem 41:3102
Yield 65%; m.p.: 165–167 °C; IR (KBr): ꢀm = 1,702, 1,675,
1,658, 1,618, 1,597 cm-1 1H NMR (DMSO-d6): d =
;
7.44–7.86 (7H, m, Ar–H), 8.06–8.23 (3H, m, Ar–H), 8.28
(2H, m, Ar–H) ppm; 13C NMR (DMSO-d6): d = 112.65,
114.58, 123.89, 125.63, 128.75, 128.83, 129.98, 131.28,
132.34, 132.62, 134.69, 137.81, 141.98, 142.45, 167.32,
168.78, 194.48 ppm.
30. Ucar H, Van derpoorten K, Depovere P, Lesieur D, Isa M,
Masereel B, Delarge J, Poupaert JH (1998) Tetrahedron 54:1763
31. Guenadil F, Aichaoui H (2003) Phosphorus. Sulfur Silicon Relat
Elem 178:1703
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