Method for Producing 5,5-Disubstituted 2-Isoxazolines

A process for preparing 5,5-disubstituted 2-isoxazolines of the formula (I)

• wherein
• R1, R2 are each independently C1-C6-alkyl or C1-C4-haloalkyl;
• or
• R1 and R2 together form a C2-C5-alkanediyl chain which may be mono- to tetrasubstituted by C1-C4-alkyl and/or interrupted by oxygen or by optionally C1-C4-alkyl-substituted nitrogen;
• which comprises reacting an oxime of the formula (II)
• where
• R3, R4 are each independently hydrogen, C1-C6-alkyl, C1-C4-alkylcarbonyl, hydroxyimino-C1-C4-alkyl, phenyl, phenyl-C1-C4-alkyl or phenyl-C2-C4-alkenyl, where the phenyl rings may be mono- or polysubstituted by C1-C4-alkyl, C1-C4-alkoxy, di-C1-C4-alkylamino, halogen, hydroxyl or nitro;
• or R3 and R4 together form a C2-C5-alkanediyl chain;
• with a carbonyl compound of the formula (III)
• in the presence of an acid catalyst or an acid-base catalyst and optionally in the presence of an organic solvent.