Chemistry Reference
In-Depth Information
Fencarbamide [3735-90-8], antispasmotic, 113.
The key step is the phosgenation of
diphenylamine 110 [86].
HS
N
O l
O
S
N
H
N
N
N
COCl
2
112
110
111
113
Fencarbamide
Flosequinan [76568-02-0], vasodilator, antihypertensive, 116.
In one method, phosge-
nation is used to synthesize the benzoxazine-2,4-dione (isatoic anhydride), a key
intermediate en route to 116 [87]. Other methods avoiding phosgene have also
been reported [88, 89].
F
N
F
NH
F
N
O
COCl
2
O
COOH
O
O
O
114
115
116
Flosequinan
Flumazenil [78755-81-4], benzodiazepine antagonist, treatment of benzodiazepine intoxi-
cation, 121.
Phosgene is used to prepare the key intermediate 6-fluoroisatoic an-
hydride 118 [90-93].
HOOC
HN
H
N
O
H
N
O
NH
2
COCl
2
119
O
N
F
F
COOH
F
O
O
117
118
120
O
N
N
O
N
F
O
121
Flumazenil
