Process for the preparation of 4-benzoylpyrazole derivatives
AssigneeSankyo Company, Limited
InventorsTakuo Konotsune, Takashi Matsui, Junzo Tobitsuka
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Abstract
4-Benzoyl-5-hydroxypyrazole derivatives are prepared by treating 5-benzoyloxypyrazole derivatives with more than 1 equivalent mole of alkaline substance or more than 1 mole of aluminum chloride per mole of the 5-benzoyloxypyrazole derivatives. The desired pyrazole derivatives are useful as a herbicide.
Claims5
In a process for the the preparation of a 4-benzoylpyrazole derivative having the formula ##STR7## wherein R.sub.1 represents an alkyl group having from 1 to 3 carbon atoms or an alkenyl group having 3 or 4 carbon atoms,
- R.sub.2 represents an alkyl group having from 1 to 3 carbon atoms,
- X represents a halogen atom, an alkyl group having from 1 to 4 carbon atoms, an alkoxy group having from 1 to 4 carbon atoms or nitro group and
- n is an integer from 1 to 3, provided that when n is an integer of 2 or 3, X may be the same or different from each other or a metal salt thereof wherein a pyrazole derivative having the formula ##STR8## wherein R.sub.1, R.sub.2, X and n have the same meaning as defined above is treated with a catalyst, the improvement which comprises said catalyst being an alkali metal carbonate in an amount of more than 1 equivalent mole per mole of the pyrazole derivative (II).
In a process for the preparation of a 4-benzoylpyrazole derivative having the formula ##STR9## wherein R.sub.1 ' is methyl or alkyl,
- X' and X" are the same or different and each is chlorine or nitro or a metal salt thereof wherein a pyrazole derivative having the formula ##STR10## wherein R.sub.1 ', X' and X" have the same meanings as defined above is treated with a catalyst, the improvement which comprises said catalyst being an alkali metal carbonate in an amount of more than 1 equivalent more per mole of the pyrazole derivative (II)'.
Dependencies are inferred from the claim text.