Reaction between 1,n-diamines, diketene, and dibenzoylacetylene in the presence of triphenylphosphine: One-pot, pseudo-five-component synthesis of bisfuramides

Article abstract of DOI:10.1055/s-0028-1083637

Using diketene as a basic reagent, a one-pot, pseudo-five-component reaction for the synthesis of highly substituted bisfuramides is described. In this method, ring opening of diketene occurs in mild condition and without a catalyst. Thus, the reaction between diketene, 1,n-diamine, and dibenzoylacetylene, in the presence of triphenylphosphine, produces bisfuramides. Georg Thieme Verlag Stuttgart.

Full text of DOI:10.1055/s-0028-1083637

3742
SHORT PAPER
Reaction between 1,n-Diamines, Diketene, and Dibenzoylacetylene in the
Presence of Triphenylphosphine: One-Pot, Pseudo-Five-Component Synthesis
of Bisfuramides
O
ne-Pot, Pseudo-F
b
ive-Compon
d
ent Synthesi
o
s
of
B
isfuram
l
ide
s
ali Alizadeh,* Reza Hosseinpour, Sadegh Rostamnia
Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran 18716, Iran
Fax +98(21)88006544; E-mail: abdol_alizad@yahoo.com; E-mail: aalizadeh@modares.ac.ir
Received 30 June 2008; revised 19 August 2008
step in diketene-based multicomponent reaction, we could
Abstract: Using diketene as a basic reagent, a one-pot, pseudo-
five-component reaction for the synthesis of highly substituted bis-
furamides is described. In this method, ring opening of diketene oc-
curs in mild condition and without a catalyst. Thus, the reaction
synthesize 2-methyl-N3-[n-({[2-methyl-4-(2-oxo-2-phe-
nylethyl)-5-phenyl-3-furyl]carbonyl}amino)alkyl]-4-(2-
oxo-2phenylethyl)-5-phenyl-3-furamides
2
in good
between diketene, 1,n-diamine, and dibenzoylacetylene, in the pres- yields. Thus, the reaction of diketene with 1,n-diamine 1,
ence of triphenylphosphine, produces bisfuramides.
dibenzoylacetylene (DBA) in the presence of triphe-
nylphosphine proceeded spontaneously at 25 °C in anhy-
drous CH2Cl2 and furnished furamides 2 within 24 hours
in 82–90% yields (Table 1).
Keywords: diketene, dibenzoylacetylene, 1,n-diamine, triphenyl-
phosphine, bisfuramide
Table 1 Bisfuramides 2 Prepared
Furan derivatives, obtained from both synthetic and natu-
ral sources, have been attracting much interest due to the
wide range of pharmaceutical applications.1 They are fre-
quently found in natural products, such as the kallolides2a
and combranolides2b and in important pharmaceuticals as
well as in flavoring and fragrance compounds. They are
often used as building blocks in organic synthesis.3 On the
other hand, a general way to improve synthetic efficiency
and also to address other criteria is the development of
multicomponent reactions.4 Multicomponent reactions
(MCRs), by virtue of their convergence, productivity, fac-
ile execution, and generally high yields of products, have
attracted much attention from the point of combinatorial
chemistry.4–8
R
NH2
H2N
n
1
O
Ph
+
O
Ph
O
Ph
O
2
O
R
H
O
CH2Cl2
N
+
N
r.t., 24 h
n
H
Ph
Me
O
2
Ph3P
+
O
Me
2
2 PhOC
COPh
Entry
Compound
R
n
1
1
3
5
7
Yield (%) of 2
1
2
3
4
5
2a
2b
2c
2d
2e
H
90
88
84
85
82
We recently reported a new class of diketene-based mul-
ticomponent reactions mediated by zwitterionic interme-
diates,9 and ring opening of the diketene cycle.10 In
previous studies we were interested in developing
diketene-based one-pot, multicomponent reactions. These
researches led to the discovery of the reaction between
amines, dibenzoylacetylenes, and diketene. In our recent
investigations, treatment of amines with diketene and
dibenzoylacetylene in the presence of triphenylphosphine
at 25 °C led to the formation of the furamide deriva-
tives.10a Although the mechanism of the reaction between
triphenylphosphine and dibenzoylacetylene in the pres-
ence of N-alkyl-3-oxobutanamide, derived from the addi-
tion of an amine to diketene, has not yet been established
in an experimental manner, a possible explanation was
proposed.10a
Me
H
H
H
The structures of compounds 2a–e were deduced from
their elemental analyses, IR, and high-field H and 13C
1
NMR spectra. The mass spectrum of 2a displayed the mo-
lecular ion (M+) peak at m/z 664, which is consistent with
the proposed structure. The IR spectrum of 2a exhibited
absorption bands due to the carbonyl groups of the ketone
and the amide at 1681 and 1638 cm–1 respectively, and the
NH group at 3260 cm–1.
In the present study we have incorporated 1,n-diamines
under similar conditions. To this end, as a preliminary
1
The H NMR spectrum of 2a, based on the symmetrical
structure, exhibited three sharp lines readily recognized as
arising from methyl group (d = 2.56), the CH2NH
(d = 3.43) and the CH2COPh (d = 4.51) protons. A broad
signal of the NH group arises at d = 7.16. The phenyl moi-
SYNTHESIS 2008, No. 23, pp 3742–3744
x
x.
x
x
.
2
0
0
8
Advanced online publication: 06.11.2008
DOI: 10.1055/s-0028-1083637; Art ID: Z15008SS
© Georg Thieme Verlag Stuttgart · New York

SHORT PAPER
One-Pot, Pseudo-Five-Component Synthesis of Bisfuramides
3743
2-Methyl-N3-[1-methyl-2-({[2-methyl-4-(2-oxo-2-phenylethyl)-
5-phenyl-3-furyl]carbonyl}amino)ethyl]-4-(2-oxo-2-phenyleth-
yl)-5-phenyl-3-furamide (2b)
ety gave rise to characteristic signals in the aromatic re-
gion of the spectrum. The 1H decoupled 13C NMR
spectrum of 2a showed 17 distinct resonances in agree-
ment with the structure. The 1H and 13C NMR spectra of
compounds 2b–e are similar to those of 2a, except for the
alkyl chain, which exhibit characteristic signals with ap-
propriate chemical shifts.
Yield: 0.59 g (88%); white powder; mp 165–167 °C.
IR (KBr): 3320 (NH), 1690 (C=O), 1673 (CONH), 1590 and 1518
cm–1 (Ph).
3
1H NMR (500.13 MHz, CDCl3): d = 1.15 (3 H, d, JH,H = 6.6 Hz,
CH3CHNH), 2.49 (3 H, s, CH3), 2.51 (3 H, s, CH3), 3.33–3.39 (1 H,
m, CH2NH), 3.49–3.52 (1 H, m, CH2NH), 4.16–4.21 (1 H, m,
CH3CHNH), 4.39–4.51 (4 H, m, 2 CH2COPh), 6.90 (1 H, d,
3JH,H = 7.5 Hz, NH), 7.20 (1 H, br, NH), 7.22–7.65 and 7.95–8.11
(20 H of 4 Ph).
In conclusion, the present one-pot multicomponent meth-
od carries the advantages that the ring opening of diketene
is performed under neutral conditions and that the total re-
action afforded good yields. The simplicity of the present
procedure makes it an interesting alternative to complex
multi-step approaches.
13C NMR (125.7 MHz, CDCl3): d = 13.46 and 13.55 (2 CH3), 14.18
(CH3CHNH), 29.68 and 34.96 (2 CH2COPh), 45.01 (CH2NH), 46.0
(CH3CHNH), 113.12 and 113.34 (2 C-3 of furan), 119.98 and 120.0
(2 C-4 of furan), 126.56 (2 CH of Ph), 126.59 (2 CH of Ph), 127.83
(CH of Ph), 127.87 (CH of Ph), 128.42 (2 CH of Ph), 128.45 (2 CH
of Ph), 128.62 (4 CH of 2 Ph), 128.71 (4 CH of 2 Ph), 130.12 and
130.36 (2 Cipso-furyl), 133.43 (CH of Ph), 133.54 (CH of Ph),
136.54 (2 Cipso-COCH2 of 2 Ph), 149.46 (2 C-5 of furan), 153 and
153.20 (2 C-2 of furan), 164.88 and 165.42 (2 CONH), 199.35 (2
COPh).
Diamines and diketene were obtained from Merck (Germany) and
Fluka (Switzerland) and were used without further purification.
Dibenzoylacetylene was prepared according to the literature proce-
dure.11 Melting points were measured on an Electrothermal 9100
apparatus. Elemental analyses for C, H, and N were performed us-
ing a Heraeus CHN-O-Rapid analyzer. Mass spectra were recorded
on a Finnigan MATT 8430 mass spectrometer operating at an ion-
ization potential of 70 eV. 1H and 13C NMR spectra were measured
(CDCl3) with a Bruker DRX-500 Avance spectrometer at 500.1 and
125.8 MHz, respectively. IR spectra were recorded on a Shimadzu
IR-460 spectrometer. Chromatography columns were prepared
from Merck silica gel 230–240 mesh.
MS: m/z (%) = 678 (M+, 2), 277 (100), 199 (21), 183 (22), 152 (16),
105 (21), 77 (57), 51 (47).
Anal. Calcd for C43H38N2O6 (678.78): C, 76.09; H, 5.64; N, 4.13.
Found: C, 76.50; H, 5.70; N, 4.10.
2-Methyl-N3-[4-({[2-methyl-4-(2-oxo-2-phenylethyl)-5-phenyl-
3-furyl]carbonyl}amino)butyl]-4-(2-oxo-2-phenylethyl)-5-phe-
nyl-3-furamide (2c)
2-Methyl-N3-[2-({[2-methyl-4-(2-oxo-2-phenylethyl)-5-phenyl-
3-furyl]carbonyl}amino)ethyl]-4-(2-oxo-2-phenylethyl)-5-phe-
nyl-3-furamide (2a): Typical Procedure
Yield: 0.58 g (84%); yellow oil.
A solution of 1,2-diamine (0.60 g, 1 mmol) and diketene (0.16 g, 2
mmol) in anhyd CH2Cl2 (5 mL) was magnetically stirred for 5 h and
then Ph3P (0.52 g 2 mmol), and a solution of dibenzoylacetylene
(0.46 g, 2 mmol) in anhyd CH2Cl2 (3 mL) was added dropwise at 25
°C over 15 min. The mixture was then allowed to stir for 24 h. The
solvent was removed under reduced pressure, and the residue was
purified by silica gel column chromatography using a mixture of
hexane–EtOAc (5:1) as eluent. The bisfuramides were then recrys-
tallized from EtOH or EtOAc; yield: 0.59 g (90%); white powder;
mp 170–172 °C.
IR (KBr): 3320 (NH), 1663 (C=O), 1593 (CONH), 1537 and 1481
cm–1 (Ph).
1H NMR (500.13 MHz, CDCl3): d = 1.16–1.24 (4 H, m, 2 CH2),
2.00 (3 H, s, CH3), 2.30 (3 H, s, CH3), 2.95–2.99 (2 H, m, CH2NH),
3.04–3.08 (2 H, m, CH2NH), 3.13 (2 H, s, CH2COPh), 4.18 (2 H, s,
CH2COPh), 6.33 (1 H, br, NH), 6.73 (1 H, br, NH), 7.04 (2 H, t,
3JH,H = 7.1 Hz, 2 CHmeta of Ph), 7.07 (2 H, t, 3JH,H = 7.4 Hz, 2 CHmeta
of Ph), 7.12 (4 H, d, 3JH,H = 7.2 Hz, 4 CHortho of 2 Ph), 7.21 (2 H, t,
3JH,H = 7.7 Hz, 2 CHmeta of Ph), 7.25 (2 H, t, 3JH,H = 7.5 Hz, 2 CHmeta
3
of Ph), 7.33 (2 H, t, JH,H = 7.5 Hz, 2 CHpara of Ph), 7.38 (2 H, t,
IR (KBr): 3260 (NH), 1681 (C=O), 1638 (CONH), 1539 and 1486
cm–1 (Ph) .
3
3JH,H = 7.1 Hz, 2 CHpara of 2 Ph), 7.68 (2 H, d, JH,H = 7.8 Hz, 2
CHortho of Ph), 7.80 (2 H, d, 3JH,H = 7.7 Hz, 2 CHortho of Ph).
1H NMR (500.13 MHz, CDCl3): d = 2.56 (6 H, s, 2 CH3), 3.43 (4 H,
d, 3JH,H = 4.5 Hz, 2 CH2NH), 4.51 (4 H, s, 2 CH2COPh), 7.16 (2 H,
br, 2 NH), 7.30 (2 H, t, 3JH,H = 7.4 Hz, 2 CHpara of 2 Ph), 7.34 (4 H,
t, 3JH,H = 7.2 Hz, 4 CHmeta of 2 Ph), 7.41 (4 H, d, 3JH,H = 8.2 Hz, 4
CHortho of 2 Ph), 7.44 (4 H, t, 3JH,H = 7.8 Hz, 4 CHmeta of 2 Ph), 7.56
13C NMR (125.7 MHz, CDCl3): d = 13.34 (2 CH3), 26.12 and 29.44
(2 CH2), 30.64 and 34.23 (2 CH2CO), 39.13 and 39.54 (2 CH2NH),
112.34 (2 C-3 of furan), 119.55 (2 C-4 of furan), 125.34 (4 CH of 2
Ph), 126.63 (2 CH of 2 Ph), 127.54 (4 CH of 2 Ph), 129.48 (4 CH of
2 Ph), 129.73 (4 CH of 2 Ph), 129.34 (2 Cipso-furyl), 132.66 (2 CH
of 2 Ph), 135.94 (2 Cipso-COCH2 of 2 Ph), 148.72 (2 C-5 of furan),
153.24 (2 C-2 of furan), 164.78 and 165.36 (2 CONH), 198.23 and
203.25 (2 COPh).
3
3
(2 H, t, JH,H = 7.5 Hz, 2 CHpara of 2 Ph), 7.97 (4 H, d, JH,H = 8.2
Hz, 4 CHortho of 2 Ph).
13C NMR (125.7 MHz, CDCl3): d = 13.46 (2 CH3), 34.83 (2
CH2COPh), 39.28 (2 CH2NH), 113.57 (2 C-3 of furan), 120.0 (2 C-
4 of furan), 126.66 (4 CH of 2 Ph), 127.86 (2 CH of 2 Ph), 128.29
(4 CH of 2 Ph), 128.64 (4 CH of 2 Ph), 128.72 (4 CH of 2 Ph),
MS: m/z (%) = 692 (M+, 2), 302 (24), 301 (100), 271 (6), 207 (17),
193 (8), 77 (4), 43 (15).
Anal. Calcd for C44H40N2O6 (692.81): C, 76.28; H, 5.82; N, 4.04.
Found: C, 76.50; H, 5.90; N, 3.95.
130.42 (2 Cipso-furyl), 133.49 (2 CH of 2 Ph), 136.66 (2 Cipso
-
COCH2 of 2 Ph), 149.0 (2 C-5 of furan), 152.08 (2 C-2 of furan),
165.72 (2 CONH), 199.14 (2 COPh).
MS: m/z (%) = 664 (M+, 2), 646 (3), 302 (100), 284 (36), 260 (27),
202 (37), 105 (68), 77 (78), 43 (50).
2-Methyl-N3-[6-({[2-methyl-4-(2-oxo-2-phenylethyl)-5-phenyl-
3-furyl]carbonyl}amino)hexyl]-4-(2-oxo-2-phenylethyl)-5-phe-
nyl-3-furamide (2d)
Anal. Calcd for C42H36N2O6 (664.75): C, 75.89; H, 5.46; N, 4.21.
Found: C, 76.00; H, 5.60; N, 4.10.
Yield: 0.61 g (85%); yellow oil.
IR (KBr): 3310 (NH), 1693 (C=O), 1645 (CONH), 1537 and 1481
cm–1 (Ph).
Synthesis 2008, No. 23, 3742–3744 © Thieme Stuttgart · New York

3744
A. Alizadeh et al.
SHORT PAPER
1H NMR (500.13 MHz, CDCl3): d = 1.16–1.29 and 1.41–1.53 (8 H,
m, 4 CH2), 2.24 (3 H, s, CH3), 2.55 (3 H, s, CH3), 3.17–3.24 (2 H,
m, CH2NH), 3.29–3.33 (2 H, m, CH2NH), 3.38 (2 H, s, CH2COPh),
4.43 (2 H, s, CH2COPh), 6.58 (1 H, br, NH), 6.98 (1 H, br, NH),
7.28 (2 H, t, 3JH,H = 7.1 Hz, 2 CHmeta of Ph), 7.32 (2 H, t, 3JH,H = 7.6
Hz, 2 CHmeta of Ph), 7.37 (4 H, d, 3JH,H = 7.5 Hz, 4 CHortho of 2 Ph),
7.46 (2 H, t,3JH,H = 7.2 Hz, 2 CHmeta of Ph), 7.51 (2 H, t, 3JH,H = 7.5
Anal. Calcd for C48H48N2O6 (748.91): C, 76.98; H, 6.46; N, 3.74.
Found: C, 77.00; H, 6.50; N, 3.70.
References
(1) (a) Lipshutz, B. H. Chem. Rev. 1986, 86, 795.
(b) Nakanishi, K. Natural Products Chemistry; Kodansha:
Tokyo, 1974. (c) Mortensen, D. S.; Rodriguez, A. L.;
Carlson, K. E.; Sun, J.; Katzenellenbogen, B. S.;
Katzenellenbogen, J. A. J. Med. Chem. 2001, 44, 3838.
(d) Raczko, J.; Jurcak, J. Stud. Nat. Prod. Chem. 1995, 16,
639. (e) Leimann, B. C. Q.; Monteiro, P. C. F.; Lazéra, M.;
Candanoza, E. R. U.; Wanke, B. Med. Mycol. 2004, 42, 95.
(f) Messer, S. A.; Jones, R. N.; Fritsche, T. R. J. Clin.
Microbiol. 2006, 44, 1782. (g) Shevchenko, N. E. Chem.
Heterocycl. Compd. 1999, 35, 164. (h) Bastian, G.; Royer,
R.; Cavier, R. Eur. J. Med. Chem. 1983, 21, 365.
(i) Kupchan, S. M.; Eakin, M. A.; Thomas, A. M. J. Med.
Chem. 1971, 111, 1147. (j) Hofnung, M.; Quillardet, V. M.;
Touati, E. Res. Microbiol. 2002, 153, 427.
3
Hz, 2 CHmeta of Ph), 7.58 (2 H, t, JH,H = 8.6 Hz, 2 CHpara of Ph),
3
7.63 (2 H, t, JH,H = 7.3 Hz, 2 CHpara of 2 Ph), 7.93 (2 H, d,
3
3JH,H = 7.8 Hz, 2 CHortho of Ph), 8.05 (2 H, d, JH,H = 7.8 Hz,
2 CHortho of Ph).
13C NMR (125.7 MHz, CDCl3): d = 13.38 (2 CH3), 26.25, 26.3,
29.06 and 29.37 (4 CH2), 30.93 and 35.13 (2 CH2CO), 39.16 and
39.24 (2 CH2NH), 112.78 (2 C-3 of furan), 120.55 (2 C-4 of furan),
126.49 (4 CH of 2 Ph), 127.89 (2 CH of 2 Ph), 128.47 (4 CH of 2
Ph), 128.63 (4 CH of 2 Ph), 128.82 (4 CH of 2 Ph), 130.29 (2 Cipso
-
furyl), 133.76 (2 CH of 2 Ph), 136.34 (2 Cipso-COCH2 of 2 Ph),
149.62 (2 C-5 of furan), 152.70 (2 C-2 of furan), 164.80 and 165.42
(2 CONH), 199.32 and 204.65 (2 COPh).
MS: m/z (%) = 720 (M+, 2), 302 (14), 277 (66), 199 (13), 183 (15),
(2) (a) Look, S. A.; Burch, M. T.; Fenical, W.; Qi-tai, Z.;
Clearly, J. J. Org. Chem. 1985, 50, 5741. (b) Fenical, W.;
Okeeda, R. K.; Basnadurraga, M. M.; Culver, P.; Jacobs, R.
S. Science 1981, 212, 1512.
152 (11), 122 (8), 105 (100), 77 (81), 57 (33), 44 (47).
Anal. Calcd for C46H44N2O6 (720.86): C, 76.65; H, 6.15; N, 3.89.
Found: C, 77.00; H, 6.30; N, 3.70.
(3) (a) Danheiser, R. L.; Stoner, E. J.; Koyama, H.; Yamashita,
D. S.; Klade, C. A. J. Am. Chem. Soc. 1989, 111, 4407.
(b) Dean, F. M. In Comprehensive Heterocyclic Chemistry,
Vol. 4; Katritzky, A. R.; Rees, C. W., Eds.; Pergamon: New
York, 1984, 313.
2-Methyl-N3-[8-({[2-methyl-4-(2-oxo-2-phenylethyl)-5-phenyl-
3-furyl]carbonyl}amino)octyl]-4-(2-oxo-2-pheenylethyl)-5-phe-
nyl-3-furamide (2e)
Yield: 0.61 g (82%); yellow oil.
(4) Tietze, L. F. Chem. Rev. 1996, 96, 115.
IR (KBr): 3315 (NH), 1693 (C=O), 1657 (CONH), 1539 and 1439
cm–1 (Ph).
(5) Dömling, A.; Ugi, I. Angew. Chem. Int. Ed. 2000, 39, 3169.
(6) Ugi, I. Angew. Chem., Int. Ed. Eng. 1962, 1, 8.
(7) Walborsky, H. M.; Periasamy, M. P. In The Chemistry of
Functional Groups, Supplement C; Patai, S.; Rappoport, Z.,
Eds.; Wiley: New York, 1983, Chap. 20, 835.
1H NMR (500.13 MHz, CDCl3): d = 1.15–1.32 and 1.40–1.56 (12
H, m, 6 CH2), 2.25 (3 H, s, CH3), 2.55 (3 H, s, CH3), 3.21–3.25 (2
H, m, CH2NH), 3.28–3.32 (2 H, m, CH2NH), 3.39 (2 H, s,
CH2COPh), 4.43 (2 H, s, CH2COPh), 6.54 (1 H, br, NH), 6.96 (1 H,
br, NH), 7.28 (2 H, t, 3JH,H = 7.1 Hz, 2 CHmeta of Ph), 7.32 (2 H, t,
(8) Dömling, A. Chem. Rev. 2006, 106, 17.
(9) (a) Alizadeh, A.; Masrouri, H.; Rostamnia, S.; Movahedi, F.
Helv. Chim. Acta 2006, 89, 923. (b) Alizadeh, A.;
Rostamnia, S.; Hu, M. L. Synlett 2006, 1592. (c) Alizadeh,
A.; Rostamnia, S.; Esmaili, A. A. Synthesis 2007, 709.
(d) Alizadeh, A.; Oskueyan, Q.; Rostamnia, S. Synthesis
2007, 2637. (e) Alizadeh, A.; Rostamnia, S.; Zhu, L. G.
Tetrahedron 2006, 62, 5641. (f) Alizadeh, A.; Rostamnia,
S.; Zohreh, N.; Oskueyan, Q. Synlett 2007, 1610.
(g) Alizadeh, A.; Rostamnia, S.; Zohreh, N.; Bijanzadeh, H.
R. Monatsh. Chem. 2008, 139, 49. (h) Alizadeh, A.;
Rostamnia, S. Synthesis 2008, 57.
(10) (a) Alizadeh, A.; Zohreh, N.; Rostamnia, S. Tetrahedron
2007, 63, 8083. (b) Alizadeh, A.; Zohreh, N. Helv. Chim.
Acta 2008, 91, 844. (c) Alizadeh, A.; Zohreh, N. Synthesis
2008, 429. (d) Alizadeh, A.; Rezvanian, A.; Zhu, L.-G.
Tetrahedron 2008, 64, 351.
3
3JH,H = 7.7 Hz, 2 CHmeta of Ph), 7.37 (4 H, d, JH,H = 7.1 Hz,
4 CHortho of 2 Ph), 7.38 (2 H, t, 3JH,H = 8.7 Hz, 2 CHmeta of Ph),7.46
(2 H, t, 3JH,H = 7.8 Hz, 2 CHmeta of Ph), 7.51 (2 H, t, 3JH,H = 7.7 Hz,
2 CHpara of 2 Ph), 7.63 (2 H, t,3JH,H = 7.5 Hz, 2 CHpara of 2 Ph), 7.93
(2 H, d, 3JH,H = 7.4 Hz, 2 CHortho of Ph), 8.05 (2 H, d, 3JH,H = 7.3 Hz,
2 CHortho of Ph).
13C NMR (125.7 MHz, CDCl3): d = 13.39 (2 CH3), 26.68, 26.77,
28.95, 29.00, 29.28 and 29.44 (6 CH2), 31.00 and 35.19 (2 CH2CO),
39.47 and 39.52 (2 CH2NH), 112.78 (2 C-3 of furan), 120.65 (2 C-
4 of furan), 126.51 (4 CH of 2 Ph), 127.90 (2 CH of 2 Ph), 128.50
(4 CH of 2 Ph), 128.65 (4 CH of 2 Ph), 128.83 (4 CH of 2 Ph),
130.34 (2 Cipso-furyl), 133.77 (2 CH of 2 Ph), 136.38 (2 Cipso
-
COCH2 of 2 Ph), 149.64 (2 C-5 of furan), 152.73 (2 C-2 of furan),
164.75 and 165.34 (2 CONH), 199.36 and 204.78 (2 COPh).
MS: m/z (%) = 748 (M+, 2), 702 (48), 701 (45), 700 (100), 438 (17),
317 (97), 96 (23).
(11) Skattebøl, L.; Jones, E. R. H.; Whiting, M. C. Org. Synth.
Coll. Vol. IV.; Wiley: New York, 1963, 792.
Synthesis 2008, No. 23, 3742–3744 © Thieme Stuttgart · New York