A highly efficient method for the synthesis of novel 1'H-spiro[indene-2,2'-quinazoline]-1,3,4'(3'H)-trione derivatives

Article abstract of DOI:10.3184/174751915X14394002808669

A series of novel ninhydrin-derived spiro-quinazolinone derivatives in moderate to good yields have been synthesised through a ferric chloride catalysed reaction in 1,2-dichloroethane.

Full text of DOI:10.3184/174751915X14394002808669

JOURNAL OF CHEMICAL RESEARCH 2015
VOL. 39 SEPTEMBER, 495–498
RESEARCH PAPER 495
A highly efficient method for the synthesis of novel 1’H-spiro[indene-2,2’-
quinazoline]-1,3,4’(3’H)-trione derivatives
Seyed Esmail Sadat-Ebrahimia, Soroor Irannezhada, Setareh Moghimib, Azadeh Yahya-Meymandia,
Mohammad Mahdavib, Abbas Shafieeb and Alireza Foroumadib*
a International Campus, Tehran University of Medical Sciences, Tehran, Iran
b Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran
A series of novel ninhydrin-derived spiro-quinazolinone derivatives in moderate to good yields have been synthesised through a ferric
chloride catalysed reaction in 1,2-dichloroethane.
Keywords: spiro compounds, primary amines, ninhydrin, ferric chloride
Nitrogenous heterocycles are found in the core structure
of numerous natural products and pharmaceutical agents.
Therefore, much effort has been devoted to access new
nitogen-containing cycles. The resultant compounds could
be utilised as potential bioactive entities in drug discovery.
The interesting biologically active molecules, quinazoline
and quinazolinones exhibit diverse properties.1,2 For instance,
gefitinib3 1 and raltitrexed4 2 have been described as EGFR
(epidermal growth factor receptor) inhibitors and antitumour
agents respectively. Moreover, spiro-based heterocycles are
of high interest to medicinal chemists for their prevalence
in many bioactive molecules. The asymmetric spiro carbon
atom often gives the molecule special stereochemical features
required for interactions with biological systems. As such,
spiro quinazolinone systems have versatile pharmacological
properties such as the potential inhibitory activity against
SIRT1 of 3 5 and the antitumour character of 4.6
Focused on 2-aminobenzamide chemistry21 and concerned
with the synthesis of new heterocyclic compounds,22-27 we
now report the FeCl3-catalysed synthesis of 1’H-spiro[indene-
2,2’-quinazoline]-1,3,4’(3’H)-trione derivatives from isatoic
anhydride 5 and amines 6, and the reaction of various
2-amino-N-substituted benzamides 7a–h and ninhydrin 8 in
1,2-dichloroethane.
Results and discussion
As mentioned above, the activity of iodine in similar reactions
encouraged us to examine other Lewis acids. So, we carried out
the model reaction by taking 8 (1 equiv.) and 2-amino-N-benzyl
benzamide 7a (1 equiv.). Benzamide derivatives were prepared
by the simple reaction between isatoic anhydride 5 and amine
derivatives 6a–h in water at room temperature (Scheme 1).28,29
Screening of the model reaction was conducted using
different solvents, Lewis acids and varying temperature as
indicated in Table 1. The transformation catalysed by FeCl3
in refluxing 1,2-dichloroethane (DCE) afforded the expected
product in 64% yield, whereas by applying CuI, CuBr and
CuBr2 as the catalyst, the yields dropped to 59%, 36%, 27%
respectively (entries 2–4). In contrast to other solvents such as
CH3CN, DMF, and 1,4-dioxane (entries 5–7), DCE was found to
be the solvent of choice based on isolated yields. There was no
noticeable improvement in the reaction yield when the reaction
was attempted at lower temperatures (entry 8). Next, varied
The most well-established strategy for the synthesis
of 2,3-dihydro quinazolinones has been based on the
condensation of 2-aminobenzamides with carbonyl
functionality employing different catalysts like CuCl2,7 TiCl4-
13
Zn,8 p-TsOH,9 NH4Cl,10 β-cyclodextrin-SO3H,11 TCT,12 I2
and acidic SiO2.14 Furthermore, utilising isatoic anhydride15-19
and 2-nitrobenzamides20 with the assistance of the appropriate
reducing agent, provides a route for an alternative method of
construction of quinazolines.
HO
H
CO2
2C
NH
F
O
HN
N
O
O
Cl
S
N
O
O
HN
N
N
N
2
1
R2
O
NH
O
H
N
O
NH
N
NH
R1
SO2
R
N
N
H
4
3
* Correspondent. E-mail: aforoumadi@yahoo.com

496 JOURNAL OF CHEMICAL RESEARCH 2015
O
O
O
O
O
O
R
8
O
R
N
RNH2 6a-h
N
O
H
N
H
O
DCE, FeCl3
Reflux, 1h
r.t.
H
2O,
NH2
N
O
H
7a-h
9a-h
5
Scheme 1
Table 1 Effects of various conditions on the model reaction
Table 2 The reaction scope for the synthesis of 1’H-spiro[indene-2,2’-
quinazoline]-1,3,4’(3’H)-trione (Scheme 1)
O
Ph
O
Entry
R
Product
Yield/%
O
O
N
N
Ph
+
1
9a
64
O
H
N
H
NH2
O
O
7a
9a
8
2
3
4
9b
9c
9d
73
79
58
Entry
1
2
3
4
5
6
7
8c
9
Solvent
DCE
DCE
DCE
DCE
CH3CN
DMF
1,4-Dioxane
DCE
DCE
Lewis acid /mol% Temp./oC
Yield/%b
64
59
36
27
38
29
47
30
FeCl3 (20)
CuI (20)
Reflux
Reflux
Reflux
Reflux
Reflux
80
Reflux
25
Reflux
Reflux
Reflux
MeO
CuBr (20)
CuBr2 (20)
FeCl3 (20)
FeCl3 (20)
FeCl3 (20)
FeCl3 (20)
FeCl3 (10)
FeCl3 (30)
–
F
5
9e
68
51
57
Trace
N
10
11c
DCE
DCE
6
7
9f
70
66
aAll reactions were run with ninhydrin (1 mmol), 2-amino-N-benzylbenzamide (1 mmol)
and Lewis acid (x mol%) in different solvents (5 mL) for 1h.
bIsolated yield.
cReaction time 12 h.
9g
8
9h
73
amounts of anhydrous FeCl3 were examined under optimised
conditions which revealed 20 mol% as the optimum amount to
promote the formation of the spiro-based product (entries 9 and
10). According to our observations complete reaction required
the presence of 20 mol% FeCl3 (entry 11).
aThe reactions were run on 1 mmol scale in 1,2-dichloroethane (5 mL) at reflux
temperature for 1 h.
bIsolated yield.
Proceeding to explore the scope of the reaction after
finding the optimised reaction conditions, 8 was treated with
the derivatives 7a–h to synthesise the target compounds.
The aliphatic, electron-rich and electron-deficient aromatic
amines could be efficiently employed affording the respective
spiro-fused ninhydrin-quinazolinones 9a–h in moderate to
good yields (Table 2). The presence of electron-donating
substituents seems beneficial for the transformation giving
the corresponding products in higher yields. Structures of
compounds 9a–h were characterised by IR, 1H, 13C NMR
spectra, MS, and analytical data. As a representative case, the
mass spectrum of 9b exhibited a molecular ion peak at m/z =
382 along with a parent ion peak at m/z = 277 resulting from
C–N bond cleavage. The presence of the NH signal at δ (H)
6.65 ppm in 1H NMR and three signals at 70.7, 162.8 and 194.5
ppm arising from the spiro carbon and carbonyl groups in the
13C NMR spectrum, confirmed the proposed structure.
easy synthetic access to the interesting spiro quinazolinone core
through commercially accessible starting materials highlights
the potential value of these compounds in the construction of
biologically active molecules.
Experimental
Melting points were taken on a Kofler hot stage apparatus and are
1
uncorrected. H and 13C NMR spectrum was recorded on Bruker FT-
500, using TMS as an internal standard. The elemental analysis was
performed with an Elementar Analysen system GmbH VarioEL CHNS
mode. Mass spectra were determined on an Agilent Technology (HP)
mass spectrometer operating at an ionisation potential of 70 eV. All
reagents and solvents were purchased from Aldrich and Merck, and
used without any purification.
Synthesis of 1’H-spiro[indene-2,2’-quinazoline]-1,3,4’(3’H)-triones
(9a–h); general procedure
FeCl3 (20 mol%) was added to the stirring mixture of ninhydrin
(1 mmol) and 2-amino-N-substituted benzamides (1 mmol) in
1,2-dichloroethane (5 mL) and refluxed for 1 h. On completion, the
solvent was removed and CH2Cl2 (15 mL) was added to the residue,
washed with water (10 mL), brine (5 mL) and dried over anhydrous
Conclusion
In summary, we have developed an efficient reaction of
ninhydrin with 2-amino-N-substituted benzamides bearing
electron-donating and electron-withdrawing substituents. The

JOURNAL OF CHEMICAL RESEARCH 2015 497
Na2SO4. The solvent was removed under reduced pressure and the
crude mass was subjected to column chromatography eluting with
petroleum ether/ethyl acetate (10:1) to furnish 9a–h as orange solids.
3’-Benzyl-1’H-spiro[indene-2,2’-quinazoline]-1,3,4’(3’H)-trione
(9a): Yield 64%; m.p. 170–172 °C; IR (KBr): 3345, 1720, 1679, 1381,
1294, 1194 cm-1; 1H NMR (500 MHz, DMSO-d6): δ 8.00 (dd, J = 5.5,
3.0 Hz, 2H), 7.78–7.89 (m, 2H), 7.77 (d, J = 7.8 Hz, 1H), 7.72 (s, 2H),
7.29 (t, J = 7.8 Hz, 1H), 7.14 (d, J = 8.4 Hz, 1H), 6.79–6.83 (m, 2H),
6.57 (d, J = 8.0 Hz, NH), 6.49 (d, J = 8.4 Hz, 2H), 4.55 (s, NCH2) ppm;
13C NMR (125 MHz, DMSO-d6): δ 48.1 (NCH2), 72.0 (Cspiro), 123.7,
123.9, 124.0, 124.1, 124.6, 131.2, 137.0, 137.3, 137.5, 137.8, 138.5,
138.8, 139.3, 161.9, 193.6 ppm; MS (70 eV): m/z = 368 (M+, 74), 339
(29), 277 (100), 255 (81), 91 (56), 76 (43); Anal calcd for C23H16N2O3:
C, 74.99; H, 4.38; N, 7.60; found: C, 74.77; H, 4.49; N, 7.49%.
(125 MHz, DMSO-d6): δ 45.0 (NCH2), 73.8 (Cspiro), 113.9, 114.2, 118.5,
119.1, 124.3, 127.5, 133.0, 133.8, 138.0, 139.1, 145.0, 162.7, 194.5 ppm;
MS (70 eV): m/z = 318 (M+, 31), 301 (25), 277 (100), 261 (52), 185 (77),
105 (62), 76 (86), 41 (64). Anal calcd for C19H14N2O3: C, 71.69; H, 4.43;
N, 8.80; found: C, 71.80; H, 4.33; N, 8.85%.
3’-Propyl-1’H-spiro[indene-2,2’-quinazoline]-1,3,4’(3’H)-trione
(9g): Yield 66 %; m.p. 123–125 °C; IR (KBr): 3381, 1755, 1649, 1378,
1254 cm-1; 1H NMR (500 MHz, DMSO-d6): δ 7.93 (d, J = 8.0 Hz, 1H),
7.69 (d, J = 8.1 Hz, 1H), 7.60 (t, J = 7.7 Hz, 1H), 7.51–7.54 (m, 2H), 7.46
(t, J = 7.2 Hz, 1H), 7.24 (t, J = 7.7 Hz, 2H), 6.54 (s, NH), 2.77–2.83 (m,
2H), 1.05–1.12 (m, 2H), 0.56 (t, J = 7.3 Hz, 3H) ppm; 13C NMR (125
MHz, DMSO-d6): δ 10.8 (CH2), 21.8 (CH3), 42.2 (NCH2), 68.7 (Cspiro),
114.5, 123.6, 127.0, 127.2, 127.3, 129.4, 130.6, 131.2, 142.4, 162.7, 193.8
ppm; MS (70 eV): m/z = 320 (M+, 69), 303 (19), 277 (100), 156 (41),
76 (34), 43(76). Anal calcd for C19H16N2O3: C, 71.24; H, 5.03; N, 8.74;
found: C, 71.30; H, 5.13; N, 8.56%.
3’-Cyclohexyl-1’H-spiro[indene-2,2’-quinazoline]-1,3,4’(3’H)-
trione (9h): Yield 73%; m.p. 110–112 °C; IR (KBr): 3296, 1771, 1645,
1376, 1225 cm-1; 1H NMR (500 MHz, DMSO-d6): δ 7.88 (dd, J = 7.9,
1.2 Hz, 1H), 7.61 (dt, J = 6.9, 1.4 Hz, 1H), 7.51 (t, J = 7.3 Hz, 1H),
7.29–7.31 (m, 2H), 7.24 (t, J = 7.3 Hz, 1H), 7.12 (t, J = 7.3 Hz, 1H),
6.74 (d, J = 7.0 Hz, 1H), 6.67 (s, NH), 4.05–4.07 (m, 1H), 1.83–1.85
(m, 2H), 1.67–1.75 (m, 2H), 1.36–1.42 (m, 1H), 1.21–1.34 (m, 4H),
1.06–1.11 (m, 1H) ppm; 13C NMR (125 MHz, DMSO-d6): δ 24.7,
25.3, 31.9, 50.0 (NCH), 68.8 (Cspiro), 116.0, 121.6, 124.5, 126.5, 128.4,
128.6, 134.3, 135.5, 148.9, 161.9, 194.0 ppm; MS (70 eV): m/z = 360
(M+, 55), 343 (41), 277 (100), 167 (49), 83 (31), 76 (38). Anal calcd for
C22H20N2O3: C, 73.32; H, 5.59; N, 7.77; found: C, 73.18; H, 5.63; N,
7.64%.
3’- (4-Methylbenzyl) -1’H-spiro[indene-2,2’-quinazoline]-
1,3,4’(3’H)-trione (9b): Yield 73%; m.p. 159–161 °C; IR (KBr): 3310,
1
1729, 1662, 1361, 1241, 841 cm-1; H NMR (500 MHz, DMSO-d6): δ
7.99 (d, J = 7.2 Hz, 1H), 7.72 (d, J = 8.0 Hz, 1H), 7.62 (t, J = 7.5 Hz,
1H), 7.50 (t, J = 7.2 Hz, 1H), 7.38 (t, J = 7.8 Hz, 1H), 7.32 (d, J = 7.5
Hz, 1H), 7.12 (t, J = 7.4 Hz, 1H), 6.92 (d, J = 7.8 Hz, 3H), 6.65 (s, NH),
6.60 (d, J = 7.8 Hz, 2H), 4.70 (s, NCH2), 2.22 (s, CH3) ppm; 13C NMR
(125 MHz, DMSO-d6): δ 20.7 (CH3), 43.8 (NCH2), 70.7 (Cspiro), 113.3,
114.4, 123.2, 125.9, 126.0, 127.0, 127.4, 128.5, 129.1, 130.7, 131.0, 135.5,
142.6, 162.8, 194.5 ppm; MS (70 eV): m/z = 382 (M+, 43), 366 (21), 277
(100), 105 (71), 76 (67), 45 (32). Anal calcd for C24H18N2O3: C, 75.38;
H, 4.74; N, 7.33; found: C, 75.19; H, 4.63; N, 7.47%.
3’- (4-Methoxybenzyl)-1’H-spiro[indene-2,2’-quinazoline]-
1,3,4’(3’H)-trione (9c): Yield 79%; m.p. 120–122 °C; IR (KBr): 3360,
1
1738, 1645, 1350, 1291, 809 cm-1; H NMR (500 MHz, DMSO-d6): δ
8.40 (s, 1H), 8.16 (m, 1H), 8.00–8.08 (m, 5H), 7.86–7.90 (m, 1H),
7.83 (d, J = 7.7 Hz, 1H), 7.78 (d, J = 7.7 Hz, 1H), 7.72 (t, J = 7.4 Hz,
1H), 7.55 (s, 1H), 6.68 (s, NH), 4.57 (s, NCH2), 3.44 (s, OMe) ppm;
13C NMR (125 MHz, DMSO-d6): δ 44.1 (NCH2), 56.0 (OCH3), 72.0
(Cspiro), 122.7, 123.5, 124.0, 124.6, 131.2, 132.5, 136.4, 137.0, 138.5,
139.3, 140.7, 148.7, 158.7, 163.5, 193.6 ppm; MS (70 eV): m/z = 398
(M+, 34), 367 (57), 277 (100), 121 (68), 76 (47), 32 (29). Anal calcd
for C24H18N2O4: C, 72.35; H, 4.55; N, 7.03; found: C, 72.19; H, 4.69; N,
6.89%.
This study was funded and supported by Tehran University of
Medical Sciences, International Campus; grant no. 94-02-169-
29597.
Received 14 June 2015; accepted 31 July 2015
Paper 1503419 doi: 10.3184/174751915X14394002808669
Published online: 1 September 2015
3’- (4-Fluorobenzyl) -1’H-spiro[indene-2,2’-quinazoline]-
1,3,4’(3’H)-trione (9d): Yield 58%; m.p. 200–202 °C; IR (KBr):
References
1
2
Z.Z. Ma, Y. Hano, T. Nomura and Y.J. Chen, Heterocycles, 1997, 46, 541.
I. Khan, A. Ibrar, N. Abbas and A. Saeed, Eur. J. Med. Chem., 2014, 76,
193.
1
3376, 1726, 1675, 1429, 1316, 1291, 845 cm-1; H NMR (500 MHz,
DMSO-d6): δ 8.05 (dd, J = 5.7, 3.1 Hz, 2H), 7.94 (dd, J = 5.7, 3.1 Hz,
2H), 7.75–7.77 (m, 2H), 7.30 (t, J = 6.9 Hz, 1H), 6.98–7.00 (m, 2H),
6.80–6.87 (m, 3H), 6.58 (d, J = 7.9 Hz, NH), 4.51 (s, NCH2) ppm;
13C NMR (125 MHz, DMSO-d6): δ 45.0 (NCH2), 73.6 (Cspiro), 114.0,
114.5 (d, JC-F = 21 Hz), 118.6, 124.1, 127.7, 128.7, 130.4 (d, JC-F = 8 Hz),
132.2, 133.9, 137.8, 138.9, 145.2, 160.3, 162.3 (d, JC-F = 129 Hz), 194.3
ppm; MS (70 eV): m/z = 386 (M+, 52), 357 (17), 277 (100), 250 (35),
109 (86), 76 (26), 50 (9). Anal calcd for C23H15FN2O3: C, 71.50; H, 3.91;
N, 7.25; found: C, 71.39; H, 3.79; N, 6.99%.
3
O. Cruz-López, A. Conejo-García, M.C. Núñez, M. Kimatrai, M.E.
García-Rubiño, F. Morales, V. Gómez-Pérez and J.M. Campos, Curr. Med.
Chem., 2011, 18, 943.
4
5
N.M. Abdel Gawad, H.H. Georgey, R.M. Youssef and N.A. El-Sayed, Eur.
J. Med. Chem., 2010, 45, 6058.
D. Rambabu, G. Raja, B. Yogi Sreenivas, G.P.K. Seerapu, L. Kumar, G.S.
Deora, D. Haldar, M.V.B. Rao and M. Pal, Bioorg. Med. Chem. Lett., 2013,
23, 1351.
6
7
K. Arya and A. Dandia, Lett. Org. Chem., 2007, 4, 378.
R.J. Abdel-Jalil, W. Voelter and M. Saeed, Tetrahedron Lett., 2004, 45,
3475.
3’-(Pyridin-2-ylmethyl)-1’H-spiro[indene-2,2’-quinazoline]-
1,3,4’(3’H)-trione (9e): Yield 68%; m.p. 212–214 °C; IR (KBr): 3300,
8
9
D.Q. Shi, L.C. Rong, J.X. Wang, Q.Y. Zhuang, X.S. Wang and H.W. Hu,
Tetrahedron Lett., 2003, 44, 3199.
S.D. Larsen, M.A. Connel, M.M. Cudahy, B.R. Evans, P.D. May, M.D.
Meglasson, T.J. O’Sullivan, H.J. Schostarez, J.C. Sih, F.C. Stevens, S.P.
Tanis, C.M. Tegley, J.A. Tucker, V.A. Vaillancourt, T.J. Vidmar, W. Watt
and J.H. Yu, J. Med. Chem., 2001, 44, 1217.
1
1730, 1665, 1381, 1249 cm-1; H NMR (500 MHz, DMSO-d6): δ 8.31
(m, 1H), 8.18 (s, 1H), 8.08–8.09 (m, 2H), 8.00 (m, 2H), 7.85 (s, 1H),
7.76 (d, J = 7.5 Hz, 1H), 7.50 (d, J = 7.6 Hz, 1H), 7.31 (t, J = 7.5 Hz,
1H), 7.17 (s, 1H), 6.82 (t, J = 7.4 Hz, 1H), 6.60 (d, J = 7.9 Hz, NH),
4.49 (s, NCH2) ppm; 13C NMR (125 MHz, DMSO-d6): δ 44.0 (NCH2),
74.2 (Cspiro), 113.5, 114.1, 118.7, 123.1, 124.4, 127.6, 132.3, 134.1,
135.6, 138.0, 139.0, 145.2, 148.3, 149.1, 163.6, 194.3 ppm; MS (70 eV):
m/z = 369 (M+, 54), 340 (25), 277 (100), 92 (64), 76 (83). Anal calcd
for C22H15N3O3: C, 71.54; H, 4.09; N, 11.38; found: C, 71.40; H, 4.16;
N, 11.58%.
10 A. Shaabani, A. Maleki and H. Mofakham, Synth. Commun., 2008, 38,
3751.
11 J. Wu, X. Du, J. Ma, Y. Zhang, Q. Shi, L. Luo, B. Song, S. Yang and D. Hu,
Green Chem., 2014, 16, 3210.
12 M. Sharma, S. Pandey, K. Chauhan, D. Sharma, B. Kumar and P.M.S.
Chauhan, J. Org. Chem., 2012, 77, 929.
13 X.S. Wang, K. Yang, J. Zhou and S.J. Tu, J. Comb. Chem., 2010, 12, 417.
14 M. Sharma, K. Chauhan, R. Shivahare, P. Vishwakarma, M.K. Suthar, A.
Sharma, S. Gupta, J.K. Saxena, J. Lal, P. Chandra, B. Kumar and P.M.S.
Chauhan, J. Med. Chem., 2013, 56, 4374.
15 P. Salehi, M. Ayyari, M. Bararjanian, S.N. Ebrahimi and A. Aliahmadi, J.
Iran. Chem. Soc., 2014, 11, 607.
3’-Allyl-1’H-spiro[indene-2,2’-quinazoline]-1,3,4’(3’H)-trione
(9f): Yield 70%; m.p. 188–190 °C; IR (KBr): 3312, 1720, 1679, 1394,
1276 cm-1; 1H NMR (500 MHz, DMSO-d6): δ 8.09–8.14 (m, 4H), 7.80
(s, 1H), 7.71 (d, J = 7.8 Hz, 1H), 7.29 (t, J = 7.6 Hz, 1H), 6.80 (t, J = 7.5
Hz, 1H), 6.57 (d, J = 8.0 Hz, NH), 5.47–5.53 (m, 1H), 4.77 (d, J = 10.2
Hz, 1H), 4.68–4.72 (m, 1H), 3.92 (d, J = 6.4 Hz, NCH2) ppm; 13C NMR
16 A.A. Mohammadi, M. Dabiri and H. Qaraat, Tetrahedron, 2009, 65, 3804.

498 JOURNAL OF CHEMICAL RESEARCH 2015
17 K. Ramesh, K. Karnakar, G. Satish, K.H.V. Reddy and Y.V.D. Nageswar,
Tetrahedron Lett., 2012, 53, 6095.
18 Z.H. Zhang, H.Y. Lu, S.H. Yang and J.W. Gao, J. Comb. Chem., 2010, 12,
643.
24 S. Farzipour, M. Saeedi, M. Mahdavi, H. Yavari, M. Mirzahekmati, N.
Ghaemi, A. Foroumadi and A. Shafiee, Synth. Commun., 2014, 44, 481.
25 T. Akbarzadeh, A. Ebrahimi, M. Saeedi, M. Mahdavi, A. Foroumadi and
A. Shafiee, Monatsh. Chem., 2014, 145, 1483.
19 S. Khaksar and S. Mohammadzadeh Talesh, C. R. Chim., 2012, 15, 779.
20 Y. Hu, M.M. Wang, H. Chen and D.Q. Shi, Tetrahedron, 2011, 67, 9342.
21 M.S. Hosseini-Zare, M. Mahdavi, M. Saeedi, M. Asadi, S. Javanshir, A.
Shafiee and A, Foroumadi, Tetrahedron Lett., 2012, 53, 3448.
22 B. Shafii, M. Saeedi, M. Mahdavi, A. Foroumadi and A. Shafiee, Synth.
Commun., 2014, 44, 215.
26 M. Mahdavi, M. Bialam, M. Saeedi, F. Jafarpour, A. Foroumadi and A.
Shafiee, Synlett, 2015, 26, 173.
27 M. Saeedi, M. Mahdavi, A. Foroumadi and A. Shafiee, Tetrahedron, 2013,
69, 3506.
28 M. Mahdavi, M. Asadi, M. Saeedi, Z. Rezaei, H. Moghbel, A. Foroumadi
and A. Shafiee, Synlett, 2012, 23, 2521.
23 M. Mahdavi, M. Asadi, M. Saeedi, M.H. Tehrani, S.S. Mirfazli, A. Shafiee
and A. Foroumadi, Synth. Commun., 2013, 43, 2936.
29 M. Mahdavi, N. Foroughi, M. Saeedi, M. Karimi, H. Alinezhad, A.
Foroumadi, A. Shafiee and T. Akbarzadeh, Synlett, 2014, 25, 385.