PROCESS FOR PREPARING 1-ALKYL-4- (2-CHLORO-3-ALKOXY-4-ALKYLSULFONYLBENZOYL)-5-HYDROXYPYRAZOLE AND RELATED COMPOUNDS

PURPOSE: Processes for preparing herbicidal 1-alkyl-4-(2-chloro-3-alkoxy-4-alkylsulfonylbenzoyl)-5-hydroxypyrazole compounds and of certain 1-halo-2-chloro-3-alkoxy-4-alkylsulfonylbenzene compounds that are useful intermediates in the manufacture of the herbicidal compounds are provided to decrease the reaction steps and to reduce the amounts of unusable by-products and waste. CONSTITUTION: The process for preparing 3-alkoxybenzene compounds of the formula 1 comprises reacting a 3-chlorobenzene compound of the formula 3 with an alkali metal alkoxide compound of the formula 4 in a liquid medium, optionally in the presence of a phase transfer catalyst, at 20-110°C. The 1-alkyl-4-(2-chloro-3-alkoxy-4-alkylsulfonylbenzoyl)-5-hydroxypyrazole compounds of the formula 6 are prepared by reacting a 1,2-dichloro-3-alkoxy-4-alkylsulfonylbenzen compound of the formula 5 with a 1-alkyl-5-hydroxypyrazole compound of the formula 7 and carbon monoxide under 3,000-50,000 kPa under anhydrous conditions at 100-120°C in the presence of an aprotic solvent, a base, a catalytic amount of a catalyst comprising a palladium 2 halide or C1-C8 alkanoate and a bis(diphenylphosphino)alkane chelant selected from 1,3-bis(diphenylphosphino)propane and 1,4-bis(diphenylphosphino)butane or a preformed palladium 2 halide or C1-C8 alkanoate salt: bis(diphenylphosphino)alkane complex prepared therefrom, and optionally in the presence of an oxygen scavenger and a phase transfer catalyst, and subsequently acidifying the reaction mixture obtained. 본 발명은 제초성 1-알킬-4-(2-클로로-3-알콕시-4-알킬설포닐벤조일)-5-하이드록시피라졸 화합물 뿐만 아니라 1-할로-2-클로로-3-알콕시-4-알킬설포닐벤젠 화합물 및 2-클로로-3-알콕시-4-알킬설포닐벤조산 화합물을, 상응하는 3-클로로 화합물과 알칼리 금속 알콕사이드 화합물을 반응시켜 양호한 수율로 제조하는 방법에 관한 것이다. 1-할로-2-클로로-3-알콕시-4-알킬설포닐벤젠과 1-할로-2,3-디클로로-4-알킬설포닐벤젠 화합물은 각각 팔라듐 II 염: 트리하이드로카빌포스핀 착화합물형 촉매의 존재하에 각각 일산화탄소 및 물, 알코올, 또는 1-알킬-5-하이드록시피라졸 화합물과의 반응에 의해 1-할로 치환체 대신 하이드록시카보닐, 알콕시카보닐, 또는 1-알킬-5-하이드록시피라졸-4-카보닐 치환체를 갖는 화합물로 전환된다.