Process for the preparation of 1-alkyl and 1-aryl-5-pyrazolecarboxylic acid derivatives
View Patent ↗The present invention relates to a process for the preparation of 1-alkyl- or 1-aryl-substituted 5-pyrazolecarboxylic acid derivatives comprising the reaction of substituted 1,3-dioxolanes and 1,4-dioxanes with alkyl- or arylhydrazines to give 1-alkyl- or 1-aryl-substituted dihydro-1H-pyrazoles, and their further reaction to give 1-alkyl- or 1-aryl-substituted 5-pyrazolecarboxylic acid derivatives, which can be used as valuable intermediates for producing insecticidally effective anthranilamides.
1. A process for the preparation of a compound of formula (I)
in which
R 1 is hydroxy, halogen, alkoxy, or aryloxy,
R 2 is hydroxy, alkoxy, arylalkoxy, halogen, O—(C═O)alkyl, O—(C═O)O-alkyl, O(C═O)haloalkyl, OSO 2 alkyl, OSO 2 -haloalkyl, or OSO 2 -aryl,
A is alkyl or
is
in which
R 3 is halogen, CN, NO 2 , alkyl, cycloalkyl, haloalkyl, halocycloalkyl, alkoxy, haloalkoxy, alkylamino, dialkylamino, or cycloalkylamino, and
Z is CH or N,
comprising, reacting a compound of formula (II)
in which
R 4 and R 5 independently of one another are hydrogen, alkyl, aryl, arylalkyl, or alkoxy, or
R 4 and R 5 taken together can form a 4-, 5- or 6-membered, saturated, optionally substituted ring which can contain 1-2 heteroatoms from the series N, S, O,
R 6 is trihalomethyl, (C═O)Oalkyl, or (C═O)Ohaloalkyl,
n is 0 or 1,
with an alkyl- or arylhydrazine of formula (III)
A-NHNH 2 (III),
in which A is alkyl or is
in which
R 3 is halogen, CN, NO 2 , alkyl, cycloalkyl, haloalkyl, halocycloalkyl, alkoxy, haloalkoxy, alkylamino, dialkylamino, or cycloalkylamino,
Z is CH or N,
in the presence of a solvent to obtain a compound of formula (IV),
in which R 6 and A are defined above,
wherein said compound of formula (IV) is optionally further reacted without prior isolation with elimination of water, in the presence of a solvent, to obtain a compound of formula (V)
in which R 2 , R 6 and A are defined above, wherein said compound
of formula (V)
is reacted in the presence of a solvent to obtain a compound of formula (I),
in which R 1 , R 2 and A are defined above.
2. The process according to claim 1 , where
R 1 is hydroxy, halogen, or (C 1 -C 6 )alkoxy,
R 2 is hydroxy, halogen, O—(C═O) (C 1 -C 6 )alkyl, OSO 2 (C 1 -C 6 )alkyl, or OSO 2 -halo(C 1 -C 6 )alkyl, and
A is (C 1 -C 4 )alkyl or
is
in which
R 3 is halogen, CN, NO 2 , (C 1 -C 6 )-alkyl, halo(C 1 -C 6 )-alkyl, or (C 1 -C 6 )alkoxy, halo(C 1 -C 6 )alkoxy, and
Z is N.
3. The process according to claim 1 , where
R 1 is hydroxy, halogen, or (C 1 -C 4 )alkoxy,
R 2 is hydroxy, halogen, or, O—(C═O)CH 3 , and
A is
in which
R 3 is chlorine, and
Z is N.
4. The process according to claim 1 , wherein n is 0.
5. The process according to claim 1 comprising, reacting said compound of formula (II)
in which n is 0 and R 4 , R 5 and R 6 are defined above, with a nucleophile of formula (VI)
H 2 L (VI),
in which L is O, NH or NR 7 ,
R 7 is alkyl,
to give a product, wherein said product is present in tautomeric forms (VIIa) and (VIIb), wherein said tautomeric forms, optionally form a ring of formula (VIIc), or (VIId), or a combination thereof:
wherein said product is subsequently reacted with a compound of formula (III)
A-NHNH 2 (III),
in which A is defined above,
to give said compound of formula (IV),
in which A and R 6 are defined above.
6. The process according to claim 1 , wherein said reaction of said compound of formula (II) with said compound of formula (III) is carried out within a temperature range from −20° C. to +100° C.
7. The process according to claim 1 , wherein 1 mol of said compound of formula (II) is reacted with 0.8 mol to 2 mol of said compound of formula (III).
8. The process according to claim 1 wherein, the compound of formula (IV) is reacted, with addition of a base, directly to obtain the compound of formula (I), where
R 1 and R 2 are hydroxy, R 6 is (C═O)Oalkyl, and
R 3 , R 4 , R 5 , A and Z are defined as in claim 1 .
9. The process according to claim 8 , further comprising using an alcohol or water as solvents, wherein the base is selected from the group consisting of LiOH, NaOH, KOH and CsOH.
10. The process according to claim 1 , wherein said reaction of said compound of formula (V) to obtain said compound of formula (I) is carried out within a temperature range from 20° C. to +150° C.
11. The process according to claim 1 , wherein said reaction of said compound of formula (V) to obtain said compound of formula (I) is carried out under acidic conditions with mineral or organic acids or under basic conditions with organic or inorganic bases.
12. The process according to claim 10 , wherein said reaction carried out with alcohol, or alcohol/HCl, alcohol/FeCl 3 , alcohol/H 2 SO 4 or alcohol/alcoholate or combinations thereof.
13. The process according to claim 1 , wherein the compound of formula (IV) is reacted, with the addition of an acid (HCl), to obtain the compound of formula (I), where
R 1 is (C═O)Oalkyl, R 2 is hydroxy and R 6 is (C═O)Oalkyl, and
R 3 , R 4 , R 5 , A and Z are defined as in claim 1 .
14. The process according to claim 10 wherein said reaction is carried out under acidic conditions with mineral or organic acids or under basic conditions with organic or inorganic bases.
15. The process according to claim 1 , wherein reaction of said compound of formula (V) to obtain said compound of formula (I) is carried out with alcohol, or alcohol/HCl, alcohol/FeCl 3 , alcohol/H 2 SO 4 and alcohol/alcoholate, or combinations thereof.