Biomedical Engineering Reference
In-Depth Information
O
O
R
1
H
R
1
H
R
3
CO
2
(CH
2
)
3
C
8
F
17
O
R
3
CO
2
(CH
2
)
3
C
8
F
17
N
N
N
Zn dust, AcOH
Sonication
F-SPE
NH
2-Nitrobenzoylchlorid
e
NO
2
O
O
H
H
Et
3
N, DMF
F-SPE
R
2
R
2
53
60
O
O
O
H
N
R
1
H
R
1
H
R
3
R
3
CO
2
(CH
2
)
3
C
8
F
17
O
N
N
DBU
N
N
NH
2
O
O
μ
W 130°C, 5 min
H
H
O
R
2
R
2
56
61
SCHEME 10.14
Synthesis of benzodiazepine-fused tricyclic compounds.
(Scheme 10.14) [39,42]. Cyclative linker cleavage with 1,8-diazabicyclo[4.3.0]non-
5-ene (DBU) finally produced the corresponding benzodiazepine-fused tetracyclic
compounds
56
.
Procter and coworkers employed fluorous thiol to form Pummerer cyclative
products
62
for DOS of nitrogen-containing heterocycles (Scheme 10.15) [44].
This work was originally developed to overcome the difficulty of solid-phase
R
1
R
1
R
1
N
N
N
R
2
O
R
2
O
R
2
O
FF
OH
O
S
65
66
67
1. Ce(NH
4
)(NO
3
)
6
MeCN/H
2
O
F-SPE
2. 2-Thienylithium
THF, 0-25°C
1. Ce(NH
4
)(NO
3
)
6
MeCN/H
2
O
F-SPE
2. DAST, CH
2
Cl
2
CAN
MeCN/H
2
O
1. Ce(NH
4
)(NO
3
)
6
MeCN/H
2
O
F-SPE
R
1
R
1
R
1
1. C
8
F
17
CH
2
CH
2
SH
CH
2
Cl
2
2. BF
3
.OEt
2
,
1 h
F-SPE
N
N
O
N
N
R
2
O
R
2
R
2
2. 1,2-Diaminobenzene
AcOH,
H
O
N
S
, 20 min
C
8
F
17
62
64
1. Ce(NH
4
)(NO
3
)
6
MeCN/H
2
O
F-SPE
2. KCN, (NH
4
)
2
CO
3
MeOH, 25-70°C
R
1
N
O
R
2
O
NH
HN
O
63
SCHEME 10.15
Thiol linker for Pummerer cyclization and DOS of heterocyclic compounds.
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