N
X
C
O
N
S
Hal
Solvents
Natural
Products
P Si
C
C
C C
C
C
236
5 1 H NMR
Carbonic Acid Derivatives (δ in ppm, J in Hz)
O
O
O
H 3 C
H
H
H
N C N
N
H
S
N
H
N
H
S
N
H
N
N
O
N
N
O
N
H
O
NH 2
N
H
O
N
H
N
H
O
O
O
O
O
O
O
O
N
O
O
N
O
O
NH
O
O
N
O
O
N
O
O
Cl
N
O
O
Br
2.48
2.36
7.85
7.85
11.4
(in DMSO)
(in DMSO)
(in D 2 O)
7.82
7.72
3.18
3.48
3.81
2.61
2.57
3.79
2.78
2.54
3.02
5.69
6.50
3 J HNCH 4.7
3 J HNCH 4.8
4.11
3.39
3.27
1.24
1.16
0.98
2.97
5.92
5.45
3.28
2.78
2.92
3.26
1.98
1.26
4.8
4.19
1.31
4.54
3.97
4.86
1.50
4.03
4.56
2.97
3.56
1.22
2.06
O
O
O
S
S
S
N
H
O
N
H
(in DMSO)
(in DMSO)