A general strategy for the synthesis of difluoromethyl-containing pyrazoles, pyridines and pyrimidines
作者:Viktor O. Iaroshenko、Verena Specowius、Katharina Vlach、Marcelo Vilches-Herrera、Dmytro Ostrovskyi、Satenik Mkrtchyan、Alexander Villinger、Peter Langer
DOI:10.1016/j.tet.2011.05.085
日期:2011.8
Difluoromethyl-containing heteroannulated pyridines, pyrimidines and pyrazoles are prepared by a two step method. The regioselective cyclizations of electron-excessive aminoheterocycles, hydrazines and amidines with CF2Cl-substituted 1,3-dicarbonyl compounds provide the corresponding CF2Cl-substituted heterocycles. Subsequent radical reactions with trimethylstannane or allyltrimethylstannane gave difluoromethyl-containing heteroannulated pyridines, pyrimidines and pyrazoles, respectively. (C) 2011 Elsevier Ltd. All rights reserved.
Method for the Production of N-Substituted (3-Dihalomethyl-1-Methyl-Pyrazole-4-yl) Carboxamides
申请人:Zierke Thomas
公开号:US20100174094A1
公开(公告)日:2010-07-08
The present invention relates to a process for preparing N-substituted (3-dihalomethylpyrazol-4-yl)carboxamides of the formula (I)
in which R
1
is optionally substituted phenyl or C
3
-C
7
-cycloalkyl, R
1a
is hydrogen or fluorine, or R
1a
together with R
1
is optionally substituted C
3
-C
5
-alkanediyl or C
5
-C
7
-cycloalkanediyl, R
2
is C
1
-C
6
-alkyl, C
2
-C
6
-alkenyl, C
2
-C
6
-alkynyl or C
1
-C
4
-alkoxy-C
1
-C
2
-alkyl, X is F or Cl and n is 0, 1, 2 or 3; which comprises
A) providing a compound of the formula (II)
in which X is F or Cl, Y is Cl or Br and R
2
has one of the meanings given above and
B) reacting a compound of the formula (II) with carbon monoxide and a compound of the formula (III)
in which R
1
, R
1a
and n have one of the meanings given above; in the presence of a palladium catalyst;
to intermediates used for the preparation according to the process according to the invention, and also to processes for their preparation.