Prodn. of 2-aryl-cyclo-hex-2-en-3-ol-1-one herbicides and miticides - comprises reacting 3-aryloxy-cyclo-hex-2-en-1-one with potassium carbonate and treating with acid

摘要

Prodn. of 2-aryl-cyclohex-2-en-3-ol-1-ones (I) comprises (a) reacting a 3-aryloxy-cyclohex-2-en-1-one (II) with anhydrous potassium carbonate in a solvent at 20-120 deg.C and (b) liberating (I) by adding acid. R = NO2 or CN; X = CH2 or C(CH3)2. The reaction is carried out using at least 1 mol. equiv. of anhydrous K2CO3 in a dipolar aprotic solvent, esp. DMSO, sulpholane or DMF, at 40-100 deg.C and the acid used in the liberation of (I) is acetic acid or an acid having an acidity greater than acetic acid. USE/ADVANTAGE - (I) are herbicides, miticides and mite ovicides. They are also intermediates for other pesticides. The method uses more readily accessible starting materials, avoids problematic operational and/or purifcn. procedures and gives cpds. (I) in better purity and yields e.g. 40-75%, than prior art processes, e.g. Tetrahedron 8, 49 (1960) where max. yield is 29%.