A new oxidative alkoxylation reaction The preparation of 5-alkoxy-4,4-dialkyl-1-aryl-3-pyrazolidinones

A new oxidative alkoxylation method is described. According to this method alkoxy groups are introduced in the 5-position of 4,4-dialkyl-1-aryl-3-pyrazolidinones by oxidation with HgO or SeO₂ in alcohols. The mechanism, the scope and limitations of the reaction are discussed. The 5-alkoxy-4,4-dialkyl-1-aryl-3-pyrazolidinones may be converted to 1-aryl-4,4-dialkyl-5-(1-aryl-3-oxo-4,4-dialkyl-5-alkoxy-5-pyrazolidinyl)-3-pyrazolidinones. The structure of the reaction products was studied by IR and NMR analyses.