Process for the preparation of pyrazole carboxylic acid amides
The invention relates to a process for the preparation of formula (I), which process comprises a) reacting the compound (II), with cyclopentadiene to (III); b) reacting this compound in the presence of an oxidant to the compound of formula (IV); c) hydrogenating this compound in the presence of a metal catalyst and an inert solvent under hydrogen atmosphere to the compound of formula (V); d) reacting this compound in the presence of a Brönsted acid followed by a reducing agent to the compound of formula (VI); e) reacting VI with a compound (VII), in the presence of a base to a compound of formula (VIII); f) converting the compound of formula VIII in the presence of an oxidizing agent to the compound of formula (IX); and g) reacting the compound of formula IX in the presence of triphenylphosphane/carbon tetrachloride or riphenylphosphane/bromotrichloromethane to the compound of formula I.
1. A process for the preparation of the compound of formula I
which process comprises
a) reacting the compound of formula II
with cyclopentadiene in the presence of an alkylnitrite and an inert solvent to a compound of formula III
b) reacting the compound of formula III in the presence of an oxidant and an inert solvent to the compound of formula IV
c) hydrogenating the compound of formula IV in the presence of a metal catalyst and an inert solvent under hydrogen atmosphere to the compound of formula V
d) reacting the compound of formula V in the presence of a Brönsted acid followed by a reducing agent to the compound of formula VI
e) reacting the compound of formula VI with a compound of formula VII
in the presence of a base to a compound of formula VIII
f) converting the compound of formula VIII in the presence of an oxidising agent to the compound of formula IX
and g) reacting the compound of formula IX in the presence of triphenylphosphane/carbon tetrachloride or triphenylphosphane/bromotrichloromethane to the compound of formula I.
2. A process according to claim 1 , wherein in step a) tert-butylnitrite is used as the alkylnitrite.
3. A process according to claim 1 , wherein in step b) meta-chloro-perbenzoic acid is used as the oxidant.
4. A process according to claim 1 , wherein in step c) rhodium on carbon is used as the metal catalyst.
5. A process according to claim 1 , wherein in step d) hydrobromic acid in water is used as Brönsted acid and a combination of activated zinc and acetic acid is used as reducing agent.
6. A process according to claim 1 , wherein step g) is performed in the presence of triphenylphosphane/carbon tetrachloride.
7. A process according to claim 1 , wherein
in step a) tert-butylnitrite is used as the alkylnitrite;
in step b) meta-chloro-perbenzoic acid is used as the oxidant;
in step c) rhodium on carbon is used as the metal catalyst;
in step d) hydrobromic acid in water is used as Brönsted acid and a combination of activated zinc and acetic acid is used as reducing agent;
and step g) is performed in the presence of triphenylphosphane/carbontetrachloride.
8. The compound of formula IV
9. The compound of formula V
10. The compound of formula VI
11. The compound of formula VIII