Method for the regioselective synthesis of 1-Alkyl-3-haloalkyl-pyrazole-4-carboxylic acid derivatives

1. A 2-acylated or 2-iminoalkylated acrylic acid hydrazone of the formula (VII)

in which

R 1 is selected from the group consisting of C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkenyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl, and C 7-19 -alkylaryl groups, each of which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, and where X′ is F, Cl, Br, or I;

R 2 is selected from C 1 -C 4 -alkyl groups which may be substituted by one, two or three halogen atoms selected from the group consisting of F, Cl, and Br, or by a CF 3 group;

Y is selected from the group consisting of (C═O)OR 3 , CN, and (C═O)NR 4 R 5 , where R 3 , R 4 , and R 5 independently of one another are selected from the group consisting of C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkenyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl, and C 7-19 -alkylaryl groups, each of which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN, and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, where X′ is F, Cl, Br, or I, and where R 4 and R 5 together with the nitrogen atom to which they are attached may form a 5- or 6-membered ring which may optionally contain one or more further heteroatoms selected from the group consisting of O, S, and an SO 2 group and which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN, and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, and where X′ is F, Cl, Br, or I;

R 8 and R 9 independently of one another are selected from the group consisting of C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkenyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl, and C 7-19 -alkylaryl groups, each of which may be substituted by one more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN, and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, and R 8 and R 9 together with the carbon atom to which they are attached may form a 5- or 6-membered ring which may optionally contain one or two further heteroatoms selected from the group consisting of O, S, and an SO 2 group, and which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN, and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, and where X′ is F, Cl, Br, or I; and

Z is selected from the group consisting of O, S, and N + R 10 R 11 , where R 10 and R 11 independently of one another are selected from the group consisting of C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkenyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl, and C 7-19 -alkylaryl groups, each of which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN, and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, where X′ is F, Cl, Br, or I, and where R 10 and R 11 together with the nitrogen atom to which they are attached may form a 5- or 6-membered ring which may optionally contain one or two further heteroatoms selected from the group consisting of O, S and an SO 2 group and which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN, and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, and where X′ is F, Cl, Br, or I.

2. A 2-acylacrylic acid hydrazone for the formula (VIIa)

in which

R 1 is selected from the group consisting of C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkenyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl, and C 7-19 -alkylaryl groups, each of which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, and where X is F, Cl, Br, or I;

R 2 is selected from C 1 -C 4 -alkyl groups which may be substituted by one, two or three halogen atoms selected from the group consisting of F, Cl, and Br, or by a CF 3 group;

Y is selected from the group consisting of (C═O)OR 3 , CN, and (C═O)NR 4 R 5 , where R 3 , R 4 , and R 5 independently of one another are selected from the group consisting of C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkenyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl, and C 7-19 -alkylaryl groups, each of which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN, and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, where X′ is F, Cl, Br, or I, and where R 4 and R 5 together with the nitrogen atom to which they are attached may form a 5- or 6-membered ring which may optionally contain one or more further heteroatoms selected from the group consisting of O, S, and an SO 2 group and which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN, and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, and where X′ is F, Cl, Br, or I; and

R 8 and R 9 independently of one another are selected from the group consisting of C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkenyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl, and C 7-19 -alkylaryl groups, each of which may be substituted by one more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN, and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, where X′ is F, Cl, Br, or I, and where R 8 and R 9 together with the carbon atom to which they are attached may form a 5- or 6-membered ring which may optionally contain one or two further heteroatoms selected from the group consisting of O, S, and an SO 2 group, and which may be substituted by one or more groups selected from the group consisting of —R′, —X, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN, and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, and where X′ is F, Cl, Br, or I.

3. A salt of the formula (VIIb)

in which

R 1 is selected from the group consisting of C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkenyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl, and C 7-19 -alkylaryl groups, each of which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —CN and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, and where X′ is F, Cl, Br, or I;

R 2 is selected from C 1 -C 4 -alkyl groups which may be substituted by one, two or three halogen atoms selected from the group consisting of F, Cl, and Br, or by a CF 3 group;

Y is selected from the group consisting of (C═O)OR 3 , CN, and (C═O)NR 4 R 5 , where R 3 , R 4 , and R 5 independently of one another are selected from the group consisting of C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkenyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl, and C 7-19 -alkylaryl groups, each of which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN, and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, where X′ is F, Cl, Br, or I, and where R 4 and R 5 together with the nitrogen atom to which they are attached may form a 5- or 6-membered ring which may optionally contain one or more further heteroatoms selected from the group consisting of O, S, and an SO 2 group and which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN, and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, and where X′ is F, Cl, Br, or I;

R 8 and R 9 independently of one another are selected from the group consisting of C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkenyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl, and C 7-19 -alkylaryl groups, each of which may be substituted by one more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN, and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, where X′ is F, Cl, Br, or I, and where R 8 and R 9 together with the carbon atom to which they are attached may form a 5- or 6-membered ring which may optionally contain one or two further heteroatoms selected from the group consisting of O, S, and an SO 2 group, and which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —SiR′ 3 , —COOR′, —(C═O)R′, —CN, and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, and where X′ is F, Cl, Br, or I; and

R 10 and R 11 independently of one another are selected from the group consisting of

C 1-12 -alkyl, C 3-8 -cycloalkyl, C 2-12 -alkenyl, C 2-12 -alkynyl, C 6-8 -aryl, C 7-19 -arylalkyl and C 7-19 -alkylaryl groups, each of which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, and where X′ is F, Cl, Br, or I, and where R 10 and R 11 together with the nitrogen atom to which they are attached may form a 5- or 6-membered ring which may optionally contain one or two further heteroatoms selected from the group consisting of O, S and an SO 2 group and which may be substituted by one or more groups selected from the group consisting of —R′, —X′, —OR′, —SR′, —NR′ 2 , —SiR′ 3 , —COOR′, —(C═O)R′, —CN and —CONR 2 ′, where R′ is hydrogen or a C 1-12 -alkyl group, and where X′ is F, Cl, Br, or I;

and the anion is selected from the group consisting of Cl − , BF 4 − , PF 6 − , SbF 6 − and AlCl 4 − .