Abstract
2,4-Difluoro-3,5-dichlorobenzoic acid, as a key intermediate for preparing quinolone-3-carboxylic acids, was synthesised from the commercially available 2,4-difluoro-3-chlorobenzoic acid in excellent yield by a reaction sequence involving nitration, selective reduction, diazotisation and chlorination.
References
1.
Zhang
Z.F.
,
Yu
A. Z.
, and
Zhou
W. C.
, Bioorg. Med. Chem. , 2007 , 15 , 7274 .
2.
Zhi
Y.
,
Gao
L. X.
,
Jin
Y.
,
Tang
C. L.
,
Li
J. Y.
,
Li
J.
, and
Long
Y. Q.
, Bioorg. Med. Chem. , 2014 , 22 , 3670 .
3.
Klauke
E.
,
Petersen
U.
, and
Grohe
K.
, US5072038, 1991-12-10.
4.
Klauke
E.
,
Petersen
U.
, and
Grohe
K.
, DE3420796, 1985-12-05.
5.
Li
L.Y.
,
Zhao
H. X.
,
Wang
J. Y.
, and
Wang
R. H.
, ACSNano , 2014 , 8 , 5352 .
6.
Parker
D.S. N.
,
Dangi
B. B.
,
Kaiser
R. I.
,
Jamal
A.
,
Ryazantsev
M. N.
,
Morokuma
K.
,
Korte
A.
, and
Sander
W.
, J. Phy. Chem. A , 2014 , 118 , 2709 .