Process for making oximes and use thereof to prepare cyclic urea fungicides

摘要

An advantageous process for preparing agriculturally suitable precursor compositions containing a compound of Formula IV is disclosed. The process involves (a) reacting a compound of Formula V with a nitrosating agent to provide a diazonium ion of Formula Va, (b) reacting the diazonium ion with a compound of Formula VI in the presence of a copper salt catalyst to obtain a reaction product containing the compound of Formula IV and greater than 100 ppm copper (based on the weight of Formula IV compound), and (c) separating copper from the Formula IV compound to obtain a purified product composition containing the compound of Formula IV and less than 10 ppm copper (based on the weight of Formula IV compound). A method for preparing a cyclic urea fungicides of Formula I is disclosed, which involves (1) preparing an agriculturally suitable precursor composition as indicated (2) reacting the oxime of Formula IV from said precursor composition with a compound of Formula III to provide a compound of Formula II, and (3) reacting the compound of Formula II with a compound of Formula MOR1. Suitable R1-R5, R7, R8 and Lg are indicated in the specification.