申请人:Sukopp Martin
公开号:US20100069646A1
公开(公告)日:2010-03-18
The present invention relates to a process for preparing difluoromethyl-substituted pyrazol-4-ylcarboxylates of the formula I
in which
R
1
is C
1
-C
8
-alkyl, C
3
-C
8
-cycloalkyl, C
1
-C
4
-alkoxy-C
1
-C
4
-alkyl, etc.; and
R
2
is hydrogen, C
1
-C
4
-alkyl, benzyl or phenyl,
wherein
a) a compound of the general formula II
in which X is fluorine, chlorine or bromine, R
1
has one of the meanings given above and R
4
is C
1
-C
8
-alkyl, C
3
-C
8
-cycloalkyl, C
2
-C
8
-alkenyl, benzyl or phenyl, is reacted with a silane compound of the general formula R
3
n
SiCl
(4-n)
in which n is 1, 2 or 3 and the substituents R
3
are independently of one another selected from the group consisting of C
1
-C
8
-alkyl and phenyl and with a metal selected from the metals of groups 1, 2, 3, 4 and 12 of the Periodic Table of the Elements having a redox potential of less than −0.7 V, based on a normal hydrogen electrode (at 25° C. and 101.325 kPa); and
b) the reaction mixture from step a) is reacted with a compound of the general formula III
R
2
HN—NH
2
(III)
in which R
2
has one of the meanings given above.
本发明涉及一种制备式I的二氟甲基取代的吡唑-4-基羧酸酯的方法,其中R1为C1-C8烷基,C3-C8环烷基,C1-C4烷氧基-C1-C4烷基等;而R2为氢,C1-C4烷基,苄基或苯基,其中a)一种通式II的化合物,其中X为氟、氯或溴,R1具有上述给定含义之一,R4为C1-C8烷基,C3-C8环烷基,C2-C8烯基,苄基或苯基,与一种通式R3nSiCl(4-n)的硅烷化合物发生反应,其中n为1、2或3,取代基R3独立地选自由C1-C8烷基和苯基组成的组,以及选择自元素周期表第1、2、3、4和12族金属中具有比标准氢电极(在25°C和101.325 kPa下)的还原电位小于-0.7 V的金属进行反应;b)来自步骤a)的反应混合物与一种通式III的化合物R2HN—NH2(III)发生反应,其中R2具有上述给定含义之一。