Synthesis of a novel class of 3-(2′-benzothiazolyl)-2,3- dihydroquinazolin-4(1H)-ones under solvent-free and catalyst-free conditions

Article abstract of DOI:10.1002/jhet.5570450612

(Chemical Equation Presented) A solvent- and catalyst-free one-pot three-component condensation reaction approach was developed for the synthesis of a new class of 3-(2′-benzothiazolyl)-2,3-dihydroquinazolin-4(1H)-ones in relatively good yields.

Full text of DOI:10.1002/jhet.5570450612

Nov-Dec 2008
1629
Synthesis of a Novel Class of 3-(2'-Benzothiazolyl)-2,3-
dihydroquinazolin-4(1H)-ones under Solvent-free
and Catalyst-free Conditions
Ahmad Shaabani,* Abbas Rahmati, and Jafar Moghimirad
Department of Chemistry, Shahid Beheshti University, P.O. Box 19839-4716, Tehran, Iran, Correspondence
author. Fax +98-21-2403041; E-mail: a-shaabani@cc.sbu.ac.ir
Received March 7, 2008
O
N
O
O
N
S
Solvent-Free
130oC
O
S
N
NH2
+
+
R
H
H
R
O
N
H
N
H
4a-k
43-69 %
1
3
2
Aryl = C6H5-, 4-CH3C6H4-, 4-CH3OC6H4-,
4-ClC6H4-, 4-BrC6H4-, 3-CH3OC6H4-,
R=
3-NO2C6H4-, 2-CH3OC6H4-, 2-CH3OC6H4-
Alkyl = -CH3, -C6H13
A solvent- and catalyst-free one-pot three-component condensation reaction approach was developed for
the synthesis of a new class of 3-(2'-benzothiazolyl)-2,3-dihydroquinazolin-4(1H)-ones in relatively good
yields.
J. Heterocyclic Chem., 45, 1629 (2008).
INTRODUCTION
reaction times in the reaction of green synthesis [7]. In
the view of the principle of green chemistry, a clean
synthesis should be a desirable without using any solvent
and catalyst [8].
2,3-Dihydroquinazolines, an important class of
heterocyclic compounds, exhibit a wide spectrum of
biological activities and pharmacological properties [1].
Additionally, these compounds can easily be oxidized to
their quinazolin-4(3H)-ones analogies, which are
themselves important biologically active compounds
[2,3]. On the other hand, a large variety of substituted
benzimidazole or benzothiazole derivatives have been
found to posses in vivo and in vitro growth inhibiting
activity against various strains of bacteria, fungi and
viruses [4]. Because of this; numerous approaches for
their synthesis have been reported in literature [5].
Multi-component reactions (MCRs) have recently been
discovered to be a powerful method for the synthesis of
organic compounds, since the products are formed in a
single step and diversity can be achieved by simply
varying each compound [6]. In addition solvent-free
organic reaction has received considerable progress in
During the course of our studies to synthesis of
substituted benzimidazole or benzothiazole heterocyclic
compounds [9] and our interest in multi-component
reactions [10], we become interested the possibility of
synthesising benzimidazo-, triazolo-, or benzothiazo-
quinazoline derivates by the one-pot three-component
condensation reactions strategy of 2-aminobenzimidazole
1 or 2-aminobenzothiazole or 3-amino-1,2,4-triazole with
isatoic anhydride 2 and aldehyde 3 under classical heating
conditions without using any catalyst and solvent
(Scheme 1).
RESULTS AND DISCUSSION
This solvent-free one-pot method involves the classical
heating of a mixture of 2-aminobenzothiazole 1, isatoic
Scheme 1
O
N
O
O
N
S
Solvent-Free
130oC
O
S
N
NH2
+
+
R
H
H
R
O
N
H
N
H
4a-k
43-69 %
1
3
2
Aryl = C6H5-, 4-CH3C6H4-, 4-CH3OC6H4-,
4-ClC6H4-, 4-BrC6H4-, 3-CH3OC6H4-,
R=
3-NO2C6H4-, 2-CH3OC6H4-, 2-CH3OC6H4-
Alkyl = -CH3, -C6H13

1630
A. Shaabani, A. Rahmati and J. Moghimirad
Vol 45
anhydride 2 and aldehyde 3 without using any catalyst to
give a new family of 3-(2'-benzothiazolyl)-2,3-dihydro-
quinazolin-4(1H)-ones 4 in relatively good yields.
In order to improve the yields, we performed reactions
using different quantities of reagents. The best result was
obtained with 1:1:1.1 ratios of 2-aminobenzothiazole,
isatoic anhydride, and aldehyde.
To explore the scope and limitations of this reaction
further, we have extended it to aliphatic and various
ortho-, meta- and para-substituted benzaldehydes in the
presence of 2-aminobenzothiazole, 2-aminobenzimidazole
and 3-amino-1,2,4-triazole. As indicated in Table 1, the
reaction proceeds efficiently with benzaldehyde, electron-
withdrawing and electron-releasing ortho-, meta- and
para-substituted benzaldehydes and aliphatic aldehydes.
However the reaction with 3-amino-1,2,4-triazole, and
2-aminobenzoimidazole is completely stopped after
heating at 130°C for 3 h. Probably this is a result of the
nucleophilicity of NH group of 3-amino-1,2,4-triazole
and 2-aminobenzimidazole as comparable to 2-amino-
benzothiazole.
8.30 for aromatic protons and one doublet of doublet (at
7.08 and 7.17, J = 7.7 Hz) for (CH3C6H4) and a doublet
for methine proton at 7.51, J = 3.01 Hz and a doublet at
8.30, J = 3.20 Hz for NH proton. The 1H spectra of 4b–k
in DMSO are similar to those of 4a, except for R group,
which exhibit characteristic signals with appropriate
chemical shifts.
1
The H decoupled 13C nmr spectrum of 4a showed 20
distinct resonances in agreement with the suggested
structures. The 1H and 13C nmr spectra of 4b–k are similar
to those of 4a except for the R1 and R2 groups, which
exhibit characteristic signals with appropriate chemical
shifts.
We have not established a mechanism for the formation
of 2,3-dihydroquinazolin-4(1H)-ones ring systems, but a
reasonable possibility is indicated in (Scheme 2).
The reaction presumably proceeds in two steps:
condensation of 2-aminobenzothiazole 1 and, isatoic
anhydride 2 then aldehydes 3 is reacted with compound 5
through a imine synthesis and then cyclisation with
addition amid nitrogen in the imine group.
The structure of the products 4 was deduced from their
IR, 1H nmr, 13C nmr and MS spectra. The mass spectra of
these compounds displayed molecular ion peak at
appropriate m/z values.
In summary, we have introduced a novel three-
component condensation reaction of a 2-aminobenzo-
thiazole, isatoic anhydride and aldehyde for the synthesis
of a new class of heterocyclic 2,3-dihydroquinazolin-
4(1H)-ones ring systems which the one-pot nature and
solvent-free protocol in the absence of any catalyst make
it an interesting approach.
The 1H nmr spectrum of 4a in DMSO exhibited a
sharp line readily recognized as arising from a methyl
group (ꢀ = 2.17) and a multiplet appeared at ꢀ = 6.93-
Scheme 2
O
O
N
O
N
O
R
H
N
S
S
O
N
N
NH2
+
H
H
R
S
O
N
H
N
H
H2N
2
5
1
6
Table 1
One-pot synthesis of benzthiazolo-quinazolinone by the condensation reaction of 2-aminobenzothiazole, isatoicanhydrid and aldehyde under
solvent- and catalyst-free conditions at 130 ˚C.
Compound
R
Time
(hours)
Mp
(°C)
Yield
(%)a
Molecular
Formula
Analysis %
Calcd./Found
S
C
H
N
4a
4b
4c
4d
4e
4f
4g
4h
4i
4CH3-C6H4-
C6H5-
2.30
2.20
3.15
3.20
4.10
3.20
3.10
3.20
3.15
5
198-199
233-236
184-186
190-193
231-234
183-186
251-253
198-200
225-230
215-222
148-151
64
66
69
53
57
61
52
61
57
61
43
C22H17N3OS
C21H15N3OS
C22H17N3O2S
C21H14ClN3OS
C21H14BrN3OS
C21H14BrN3OS
C21H14N4O3S
C22H17N3OS
C22H17N3O2S
C16H13N3OS
C21H23N3OS
71.14/71.23
70.57/70.69
68.20/68.33
64.36/64.45
57.81/58.01
57.81/58.97
62.68/62.54
71.14/71.29
68.20/68.09
65.06/64.86
69.01/68.92
4.61/4.64
4.23/4.24
4.42/4.44
3.60/3.63
3.23/3.22
3.23/3.23
3.51/3.52
4.61/4.63
4.42/4.43
4.44/4.45
6.34/6.36
11.31/11.26
11.76/11.71
10.85/10.81
10.72/10.69
9.63/9.64
8.63/8.61
8.97/8.93
8.28/8.26
8.18/8.17
7.35/7.34
7.35/7.36
7.97/7.93
8.63/8.65
8.28/8.31
10.86/10.85
8.77/8.73
4CH3O-C6H4-
4Cl-C6H4-
4Br-C6H4-
3Br-C6H4-
3NO2-C6H4-
2CH3-C6H4-
2CH3O-C6H4-
CH3-
9.63/9.61
13.92/13.95
11.31/11.29
10.85/10.82
14.23/14.20
11.50/11.52
4j
4k
C6H13-
3.30
[a] isolated yield.

Nov-Dec 2008
Synthesis of a Novel Class of 3-(2'-Benzothiazolyl)-2,3-dihydroquinazolin-4(1H)-ones
1631
ir (KBr): 3350, 1633, 1608, 1505, 1430, 1304, 1233 cm-1; H
nmr: ꢀ 3.63 (s, OCH3), 6.78(t, J= 7.34 Hz, CH), 6.83 (d, J= 7.67
Hz, 2CH), 6.94 (d, J= 8.08 Hz, CH), 7.21(d, J= 7.81 Hz, 2CH),
7.34 (t, J= 7.13 Hz, CH), 7.39 (t, J= 7.12 Hz, CH), 7.44 (t, J=
7.52 Hz, CH), 7.52 (brs, CH(sp3)), 7.78 (d, J= 7.65 Hz, CH),
7.81 (d, J= 7.61 Hz, CH), 8.04 (d, J= 7.73 Hz, CH), 8.32 (br s,
NH) ppm; 13C nmr: ꢀ 55.48, 68.21, 114.06, 114.39, 116.24,
118.79, 121.38, 122.20, 124.55, 126.74, 127.50, 128.85, 131.84,
133.07, 135.94, 147.42, 148.16, 158.19, 159.52, 162.12 ppm;
ms: m/z 388(M+1, 50), 253(100), 239(90), 167(20), 77(10).
Anal. Calcd for C22H17N3O2S: C, 68.20; H, 4.42; N, 10.85; S,
8.28%. Found: C, 68.33; H, 4.44; N, 10.81; S, 8.26 %.
1
EXPERIMENTAL
Melting points were measured on an Electrothermal 9100
apparatus. Mass spectra were recorded on a FINNIGAN-MAT
8430 mass spectrometer operating at an ionization potential of
70 eV. IR spectra were recorded on a Shimadzu IR-470
spectrometer. The elemental analyses were performed with an
Elementar Analysensysteme GmbH VarioEL CHNS mode.1H,
and 13C nmr spectra were recorded on a BRUKER DRX-300
AVANCE spectrometer at 300.13, and 75.47 MHz. nmr spectra
were obtained on solutions in DMSO-d6. All the products are
new compounds, which were characterized by IR, H, and 13C
1
3-(2'-Benzothiazolyl)-2,3-dihydro-2-(4-cholorophenyl)-
quinazolin-4(1H)-one (4d). Colorless crystals. mp 190-193˚C;
nmr spectral data.
Melting points were measured on an Electrothermal 9100
apparatus. Mass spectra were recorded on a FINNIGAN-MAT
8430 mass spectrometer operating at an ionization potential of
70 eV. IR spectra were recorded on a Shimadzu IR-470
spectrometer. The elemental analyses were performed with an
Elementar Analysensysteme GmbH VarioEL CHNS mode.1H,
and 13C nmr spectra were recorded on a BRUKER DRX-300
AVANCE spectrometer at 300.13, and 75.47 MHz. nmr spectra
were obtained on solutions in DMSO-d6. All the products are
1
ir (KBr): 3335, 1634, 1609, 1506, 1403, 1254 cm-1; H nmr: ꢀ
6.81(t, J= 7.35 Hz, 1CH), 6.96 (d, J= 8.20 Hz, 1CH), 7.30 (d,
J= 8.53 Hz, 2CH), 7.46(t, J= 7.17 Hz, 1CH), 7.54(d, J= 3.99
Hz, 1CH(sp3)), 7.78 (d, J= 8.00 Hz, 1CH), 7.79 (d, J= 7.67
Hz, 1CH), 8.06 (d, J= 7.68 Hz, 1CH), 8.34 (d, J= 4.06 Hz,
NH) ppm; 13C nmr: ꢀ 64.46, 113.57, 115.77, 118.55, 120.88,
121.61, 124.08, 126.21, 127.62, 128.37, 128.51, 132.58,
132.94, 135.49, 138.53, 146.58, 147.58, 157.59, 161.40 ppm;
ms: m/z (%) 271(27), 257(70), 242(100), 178(35), 152(50),
130(25), 108(20). Anal. Calcd for C21H14ClN3OS: C, 64.36; H,
3.60; N, 10.72; S, 8.18 %. Found: C, 64.53; H, 3.65; N, 10.69;
S, 8.17%.
new compounds, which were characterized by IR, H, and 13C
nmr spectral data.
1
Typical procedure for the synthesis of 3-(2'-benzothia-
zolyl)-2,3-dihydro-2-(4-methylphenyl)-4(1H)-quinazolinone
(4a). A mixture of isatoic anhydride (0.130 g, 1 mmol),
p-methylbenzaldehyde (0.132 g, 1.1 mmol), and 2-aminobenz-
thiazole (0.150 g, 1 mmol) was successively added to a screw-
capped vial containing a magnetic stirring bar and was heated at
130˚C in a preheated oil bath for 2.30 h. Then the reaction
mixture was washed with cold water (2ꢀ10 ml) and the solid
residue was crystallized from acetonitril to yield 0.23 g of 4a as
colorless crystals (64%). Colorless crystals. mp 198-199˚C; ir
(KBr): 3340, 1631, 1609, 1506, 1432, 1254 cm-1; 1H nmr: ꢀ 2.17
(s, CH3), 6.78 (t, J= 7.29 Hz, CH), 6.93 (d, J= 8.09 Hz, CH),
7.08 (d, J= 7.68 Hz, 2CH), 7.17 (d, J= 7.77 Hz, 2CH), 7.35 (t, J=
7.80 Hz, CH), 7.38 (t, J= 10.16 Hz, CH), 7.45 (t, J= 7.25 Hz,
CH), 7.51 (d, J= 3.01 Hz, CH(sp3)), 7.77 (t, J= 7.03 Hz, CH),
7.79 (d, J= 6.95 Hz, CH), 8.04 (d, J= 7.72 Hz, CH), 8.30 (d, J=
7.72 Hz, CH), 8.30 (d, J= 3.20 Hz, NH) ppm; 13C nmr: ꢀ 20.97,
68.36, 114.09, 116.23, 118.82, 121.37, 122.21, 124.56, 126.16,
126.75, 128.84, 129.54, 133.06, 135.93, 137.02, 138.02, 147.40,
148.14, 151.18, 162.13 ppm; ms: m/z (%) 372 (M+1, 90), 237
(100), 165 (20), 130 (20), 77 (25). Anal. Calcd for C22H17N3OS:
C, 71.14; H, 4.61; N, 11.31; S, 8.63 %. Found: C, 71.43; H,
4.64; N, 11.26; S, 8.61 %.
3-(2'-Benzothiazolyl)-2,3-dihydro-2-(4-bromophenyl)-
quinazolin-4(1H)-one (4e). Colorless crystals. mp 231-234˚C;
1
ir (KBr): 3350, 1630, 1612, 1501, 1431, 1389, 1228 cm-1; H
nmr: ꢀ 6.81(t, J= 7.47 Hz, 1CH), 6.96 (d, J= 8.18 Hz, 1CH), 7.25
(d, J= 8.25 Hz, 2CH), 7.36(t, J= 7.41 Hz, 1CH), 7.41(t, J= 8.39
Hz, 1CH), 7.45(t, J= 7.71 Hz, 1CH), 7.51 (d, J= 8.60 Hz, 2CH),
7.53 (d, J= 4.20 Hz, 1CH(sp3)), 7.78 (d, J= 7.64 Hz, 1CH), 7.80
(d, J= 7.42 Hz, 1CH), 8.05 (d, J= 7.79 Hz, 1CH), 8.34(d, J= 3.88
Hz, 1NH) ppm; 13C nmr: ꢀ 68.45, 114.09, 116.26, 118.89,
121.40, 122.22, 124.58, 126.25, 126.76, 128.67, 128.91, 129.04,
133.11, 135.97, 140.04, 147.38, 148.15, 158.24, 162.13 ppm;
ms: m/z (%) 223 (75), 208 (100), 194 (20), 149(50), 105(30), 77
(50). Anal. Calcd for C21H14BrN3OS: C, 57.81; H, 3.23; N, 9.63;
S, 7.35 %. Found: C, 58.01; H, 3.22; N, 9.64; S, 7.34 %.
3-(2'-Benzothiazolyl)-2,3-dihydro-2-(3-boromophenyl)-quin-
azolin-4(1H)-one (4f). Colorless crystals. mp 183-186˚C; ir
(KBr): 3385, 1644, 1609, 1499, 1435, 1380, 1231 cm-1; 1H nmr: ꢀ
6.85(t, J= 7.33 Hz, 1CH), 6.90 (d, J= 8.25 Hz, 1CH), 7.08-7.44
(m, 6CHarom), 7.68 (s, 1CH), 7.69 (t, J= 8.04 Hz, 1CH), 7.71 (d,
J= 4.36 Hz, 1CH), 7.93 (d, J= 7.45 Hz, 1CH), 8.01 (d, J= 7.65 Hz,
1CH), 8.06(d, J= 4.37 Hz, 1NH) ppm; 13C nmr: ꢀ 69.09, 113.40,
116.59, 119.14, 121.55, 122.17, 122.35, 124.67, 126.00, 126.74,
128.53, 128.75, 131.03, 133.03, 134.18, 136.12, 138.72, 145.85,
147.89, 157.28, 162.21 ppm; ms: m/z (%) 436( M+1, 40), 434( M-
1, 30), 303(100), 301(98), 288(90), 286(90), 152(35), 77 (35).
Anal. Calcd for C21H14BrN3OS: C, 57.81; H, 3.23; N, 9.63; S, 7.35
%. Found: C, 58.97; H, 3.23; N, 9.58; S, 7.36 %.
3-(2'-Benzothiazolyl)-2,3-dihydro-2-(phenyl)-quinazolin-
4(1H)-one (4b). Colorless crystals. mp 233-236˚C; ir (KBr):
3350, 1630, 1612, 1501, 1431, 1389, 1228 cm-1; H nmr: ꢀ 6.79
1
(t, J= 7.43 Hz, CH), 6.97 (d, J= 8.12 Hz, CH), 7.22-7.40 (m,
C6H5), 7.37 (t, J= 7.03 Hz, CH), 7.42 (t, J= 7.44 Hz, CH), 7.60
(d, J= 3.59 Hz, CH(sp3)), 7.79 (d, J= 8.13 Hz, CH), 7.82 (t, J=
8.76 Hz, CH), 8.05 (d, J= 7.72 Hz, CH), 8.38 (d, J= 3.63 Hz,
NH) ppm; 13C nmr: ꢀ 68.45, 114.09, 116.26, 118.89, 121.40,
122.22, 124.58, 126.25, 126.76, 128.67, 128.91, 129.04, 133.11,
135.97, 140.04, 147.38, 148.15, 158.24, 162.13 ppm; ms: m/z
(%) 223 (M-134, 75), 208 (100), 194 (20), 149 (50), 105 (30),
77 (50). Anal. Calcd for C21H15N3OS: C, 70.57; H, 4.23; N,
11.76; S, 8.97 %. Found: C, 70.79; H, 4.24; N, 11.71; S, 8.93%.
3-(2'-Benzothiazolyl)-2,3-dihydro-2-(4-methoxyphenyl)-
quinazolin-4(1H)-one (4c). Colorless crystals. mp 184-186˚C;
3-(2'-Benzothiazolyl)-2,3-dihydro-2-(3-nitrophenyl)-quina-
zolin-4(1H)-one (4g). Colorless crystals. mp 251-253˚C; ir
(KBr): 3440, 1637, 1619, 1539, 1524, 1434, 1340 cm-1; 1H nmr:
ꢀ 6.82 (t, J= 7.55 Hz, 1CH), 7.01 (d, J= 8.18 Hz, 1CH), 7.35-
7.48 (m, 3CH), 7.57-7.64 (m, 2CH), 7.69 (d, J= 4.23 Hz,
1CH(sp3)), 7.78 (d, J= 9.18 Hz, 1CH), 7.81 (d, J= 9.06 Hz,
1CH), 8.07 (d, J= 8.05 Hz, 1CH), 8.11 (d, J= 8.13 Hz, 1CH),
8.28 (s, 1CH), 8.47 (d, J= 3.95 Hz, 1NH) ppm; 13C nmr: ꢀ 67.30,
113.46, 115.97, 118.89, 120.73, 120.98, 121.83, 123.35, 124.26,

1632
A. Shaabani, A. Rahmati and J. Moghimirad
Vol 45
126.35, 128.49, 130.32, 132.05, 132.61, 135.75, 141.89, 146.36,
147.52, 147.98, 157.57, 161.26 ppm; ms: m/z (%) 403 (M+1,
30), 354 (30), 268 (100), 207 (50), 105 (20), 77 (20). Anal.
Calcd for C21H14N4O3S: C, 62.68; H, 3.51; N, 13.92; S, 7.97 %.
Found: C, 62.54; H, 3.52; N, 13.96; S, 7.93%.
Acknowledgement. We gratefully acknowledge financial
support from the Research Council of Shahid Beheshti
University.
REFERENCES
3-(2'-Benzothiazolyl)-2,3-dihydro-2-(2-methylphenyl)-quin-
azolin-4(1H)-one (4h). Colorless crystals. mp 198-200˚C; ir
(KBr): 3330, 1631, 1609, 1501, 1452, 1389, 1231 cm-1; 1H nmr:
ꢀ 2.72 (s, CH3), 6.81 (d, J= 7.83 Hz, 1CH), 6.82 (t, J= 7.58 Hz,
1CH), 6.96-7.44 (m, 7CHarom), 7.59 (d, J= 4.09 Hz, 1CH),
7.71 (d, J= 7.96 Hz, 1CH), 7.91-8.01 (m, 2CHarom), 7.95 (d, J=
4.48 Hz, NH) ppm; 13C nmr: ꢀ 19.67, 66.92, 113.39, 116.21,
118.70, 121.48, 122.12, 124.00, 124.55, 126.53, 126.68, 128.74,
128.88, 131.67, 133.00, 135.85, 136.00, 138.61, 146.28, 147.99,
157.48, 162.40 ppm; ms: m/z (%) 372 (M+1, 90), 237 (100), 193
(30), 165 (20), 105 (20), 77 (30). Anal. Calcd for C22H17N3OS:
C, 71.14; H, 4.61; N, 11.31; S, 8.63%. Found: C, 71.29; H, 4.63;
N, 11.19; S, 8.65%.
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3-(2'-Benzothiazolyl)-2,3-dihydro-2-(2-methoxyphenyl)-quin-
azolin-4(1H)-one (4i). Colorless crystals. mp 225-230˚C; ir
(KBr): 3346, 1647, 1614, 1511, 1460, 1440 cm-1; 1H nmr: ꢀ 3.94
(s, OCH3), 6.71-6.89 (m, 4CH), 7.07 (d, J= 8.13 Hz, 1CH), 7.19-
7.43 (m, 4CH), 7.67 (d, J= 3.45 Hz, 1CH), 7.73 (d, J= 7.86 Hz,
1CH), 7.77 (d, J= 3.48 Hz, 1NH), 7.87 (d, J= 7.77 Hz, 1CH),
8.01 (d, J= 7.77 Hz, 1CH) ppm; 13C nmr: ꢀ 56.25, 65.71, 112.14,
113.05, 116.01, 118.49, 120.35, 121.46, 122.11, 124.54, 125.50,
126.68, 127.15, 128.68, 130.29, 133.04, 135.85, 147.15, 148.01,
157.08, 157.56, 162.65 ppm; ms: m/z (%) 388 (60), 253 (100),
238 (50), 167 (20), 132 (25), 77 (20). Anal. Calcd for
C22H17N3O2S: C, 68.20; H, 4.42; N, 10.85; S, 8.28%. Found: C,
68.09; H, 4.43; N, 10.79; S, 8.31 %.
[3] (a) Gravier, D.; Dupin, J. P.; Casadebaig, F.; Hou, G.;
Boisseau, M.; Bernard, H. Pharmazie 1992, 47, 91. (b) Baker, B. R.;
Schaub, R. E.; Joseph, J. P.; McEvoy, F. J.; Williams, J. H. J. Org.
Chem. 1953, 18, 133. (c) Wolfe, J. F.; Rathman, T. L.; Sleevi, M. C.;
Campbell, J. A.; Greenwood, T. D. J. Med. Chem. 1990, 33, 161.
[4] (a) Paget, C. J.; Chamberlin, J. W.; Wikel, J. H. British Patent
1,568,542, 1982; Chem. Abstr.1983, 91, 30754. (b) Paget, C. J.; Kisner,
K.; Stone, R. L.; Delong, D. C. J. Med. Chem. 1969, 12, 1010. (c)
Tamm, J. In The Strategy in Chemotherapy, Cowan, S. T.; Rowatt, E.
Ed, Cambridge University Press, Cambridge, 1958.
[5] (a) Sharma, S. D.; Kaur, V. Synthesis 1989, 677. (b) Kung, P. P.;
Casper, M. D.; Cook, K. L.; Willson-Lin-gardo, L. J. Med. Chem. 1999, 42,
4705. (c) Corbett, J. W.; Ko, S. S.; Rodgers, J. D.; Gearhart, L. A.; Magnus,
N. A.; Bachheler, L. T.; Diamond, S.; Jeffey, S.; Trainor, G. L.; Anderson,
P. S.; Erickson-Vitanen, K. J. Med. Chem. 2000, 43, 2019. (d) Liu, J. F.;
Lee, J.; Dalton, A. M.; Bi, G.; Yu, L.; Baldino, C. M.; McElory, E.; Brown,
M. Tetrahedron Lett. 2005, 46, 1241. (e) Moore, J. A.; Sutherland, G. J.;
Sowerby, R.; Kelly, E. G.; Palermo, S.; Webster, W. J. Org. Chem.1969, 34,
887. (f) Shi, D.; Rong, L.; Wang, J.; Zhuang, Q.; Wang, X.; Hu, H.
Tetrahedron Lett. 2003, 44, 3199. (g) Sadanandam, Y. S.; Reddy, K. R. M.;
Rao, A. B. Eur. J. Org. Chem. 1987, 22, 169. (h) Salehi, P.; Dabiri, M.;
Zolfigol, M. A.; Baghbanzadeh, M. Synlett 2005, 1155. (i) Dabiri, M.;
Salehi, P.; Otokesh, S.; Baghbanzadeh, M.; Kozehgary, G.; Mohammadi, A.
A. Tetrahedron Lett. 2005, 46, 6123. (j) Baghbanzadeh, M.; Salehi, P.;
Dabiri, M.; Kozehgary, G. Synthesis 2006, 344.
3-(2'-Benzothiazolyl)-2,3-dihydro-2-methyl-quinazolin-
4(1H)-one (4j). Colorless crystals. mp 215-222˚C; ir (KBr):
1
3307, 1645, 1614, 1508, 1440 cm-1; H nmr: ꢀ 1.62 (d, J= 6.04
Hz, CH3), 4.80 (brs, NH), 6.72 (q, J= 5.89 Hz, 1CH), 6.80 (d, J=
8.08 Hz, 1CH), 6.95 (t, J= 7.48 Hz, 1CH), 7.31 (t, J= 7.26 Hz,
1CH), 7.43 (t, J= 8.20 Hz, 1CH), 7.45 (t, J= 7.79 Hz, 1CH), 7.84
(d, J= 7.82 Hz, 1CH), 7.58 (d, J= 7.58 Hz, 1CH), 8.07 (d, J=
7.80 Hz, 1CH) ppm; 13C nmr: ꢀ 19.68, 65.12, 113.06, 116.23,
118.47, 121.35, 122.02, 124.37, 126.60, 128.89, 133.01, 135.83,
147.38, 148.28, 127.45, 161.35 ppm; MS: m/z (%) 296 (M+1,
40), 280 (100), 161 (25), 77 (10). Anal. Calcd for C16H13N3OS:
C, 65.06; H, 4.44; N, 14.23; S, 10.86 %. Found: C, 64.86; H,
4.45; N, 14.20; S, 10.85%.
[6] (a) Kappe, C. O. Curr. Opin. Chem. Biol. 2002, 6, 314. (b)
Domling, A.; Ugi, I. Angew. Chem. In. Ed. 2000, 39, 3168. (c)
Multicomponent Reactions, Zhu, J.; Bienayme, H. Ed. Wiley-VCH:
Weinheim, 2005.
[7] (a) Cave, G. W. V.; Raston, G. L.; Scott, J. L. Chem.
Commun. 2001, 2159. (b) Tanaka, K.; Toda, F. Chem. Rev. 2000, 100,
1025. (c) Metzger, J. O. Angew. Chem. Int. Ed. 1998, 37, 2975.
[8] Anastas, P. T.; Warner, J. C. Green Chemistry—Theory and
Practice, Oxford University Press, New York, 1998.
3-(2'-Benzothiazolyl)-2,3-dihydro-2-hexyl-quinazolin-
4(1H)-one (4k). Colorless crystals. mp 148-151˚C; ir (KBr):
1
3370, 2926, 1633, 1513, 1435 cm-1; H nmr: ꢀ 0.80 (t, J= 6.83
Hz, CH3), 1.27-1.29 (m, 3CH2), 1.31 (m, CH2), 1.66 (m, CH2),
1.89 (m, CH2), 6.37 (ddd, J= 7.53 Hz, J= 6.37 Hz, J= 3.70 Hz,
CH), 6.81 (t, J= 7.58 Hz, CH), 6.90 (d, J= 8.12 Hz, CH), 7.34 (t,
J= 7.49 Hz, CH), 7.42 (t, J= 7.91 Hz, CH), 7.46 (t, J= 7.32 Hz,
CH), 7.67 (d, J= 3.60 Hz, NH), 7.81 (d, J= 7.99 Hz, CH), 7.82
(d, J= 7.61 Hz, CH), 8.00 (d, J= 7.78 Hz, CH) ppm; 13C nmr: ꢀ
14.35, 22.44, 24.97, 28.40, 31.48, 32.48, 68.06, 113.49, 116.06,
118.35, 121.27, 122.05, 124.35, 126.62, 128.86, 132.98, 135.83,
147.18, 148.22, 157.68, 161.53 ppm; ms: m/z (%) 380 (M+15,
10), 280 (100), 245 (30). Anal. Calcd for C21H23N3OS: C, 69.01;
H, 6.34; N, 11.50; S, 8.77 %. Found: C, 68.92; H, 6.37; N,
11.52; S, 8.73%.
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Chem. Lett. 2005, 15, 5553. (b) Shaabani, A.; Safaei, H. R.; Bijanzadeh,
H. R.; Synth. Commun. 2001, 31, 2639.
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Tetrahedron Lett. 2004, 45, 8409. (b) Shaabani, A.; Teimouri, M. B.;
Bijanzadeh, H. R. Tetrahedron Lett. 2002, 43, 9151. (c) Shaabani, A.;
Yavari, I.; Teimouri, M. B.; Bazgir, A.; Bijanzadeh, H. R. Tetrahedron
2001, 57, 1375. (d) Shaabani, A.; Bazgir, A. Tetrahedron Lett. 2004, 45,
2575. (e) Shaabani, A.; Bazgir, A.; Teimouri, F. Tetrahedron Lett. 2003,
44, 857. (f) Shaabani, A.; Bazgir, A.; Bijanzadeh, H. R. Mol. Divers.
2004, 8, 141. (g) Shaabani, A.; Rahmati, A. Catal. Lett. 2005, 100, 177.