Process for producing 4-benzoyl-5-hydroxypyrazoles

A process for producing a 4-benzoyl-5-hydroxylpyrazole of the formula III:

• ##STR23## wherein A is an alkyl group having from 1 to 3 carbon atoms, an allyl group or a propargyl group, B is a hydrogen atom or a methyl group, R.sup.1 is an alkyl group having from 1 to 4 carbon atoms, an alkoxy group having from 1 to 4 carbon atoms, a trifluoromethyl group, a nitro group, a cyano group or a halogen atom, R.sup.2 is a hydrogen atom, an alkyl group having from 1 to 4 carbon atoms, an alkoxy group having from 1 to 4 carbon atoms, a hydroxy group, an alkoxyalkoxy group having from 3 to 6 carbon atoms, an alkoxyalkyl group having from 2 to 5 carbon atoms, an alkoxycarbonyl group having from 2 to 5 carbon atoms, a carboxyl group, a nitro group, a cyano group or a halogen atom, and R.sup.3 is an alkylthio group having from 1 or 2 carbon atoms, an alkylsulfinyl group having 1 or 2 carbon atoms, an alkanesulfonyl group having 1 or 2 carbon atoms, a trifluoromethyl group, a nitro group, a cyano group or a halogen atom, which comprises reacting carbon monoxide and a 5-hydroxypyrazole of the formula II:
• ##STR24## wherein A and B are as defined above, to a substituted benzene of the formula I:
• ##STR25## wherein X is a bromine atom, an iodine atom or a diazonium tetrafluoroboron salt group, R.sup.1 is as defined above, provided that when X is a bromine atom, R.sup.1 is a fluorine atom or a chlorine atom, and when X is an iodine atom, R.sup.1 is a fluorine atom, a chlorine atom or a bromine atom, R.sup.2 is as defined above, provided that when X is a bromine atom, R.sup.2 is a fluorine atom or a chlorine atom, and when X is an iodine atom, R.sup.2 is a fluorine atom, a chlorine atom or a bromine atom, and R.sup.3 is as defined above, provided that when X is a bromine atom, R.sup.3 is a fluorine atom or a chlorine atom, and when X is an iodine atom, R.sup.3 is a fluorine atom, a chlorine atom or a bromine atom, in the presence of a base and a catalyst of Group VIII of the Periodic Table.