Process for preparing 1-alkyl-4-(2-chloro-3-alkoxy-4-alkylsulfonylbenzoyl)-5-hydroxypyrazole and related compounds

Abstract From the Canadian patent

Herbicidal 1-alkyl-4-(2-chloro-3-alkoxy-4-alkylsulfonylbenzoyl)-5hydroxypyrazole compounds, as well as 1-halo-2-chloro-3-alkoxy-4alkylsulfonylbenzene compounds and 2-chloro-3-alkoxy-4-alkylsulfonylbenzoic acid compounds, were prepared in good yield by the reaction of the corresponding 3-chloro compound with an alkali metal alkoxide compound. 1-Halo- 2-chloro-3-alkoxy-4-alkylsulfonylbenzene and 1-halo-2,3-dichloro-4alkylsulfonylbenzene compounds were converted to compounds having hydroxycarbonyl, alkoxycarbonyl, or 1-alkyl-5-hydroxypyrazole-4-carbonyl substituents in place of the 1-halo substituent by reaction with carbon monoxide and water, an alcohol, or a 1-alkyl-5-hydroxypyrazole …