Aminolysis of 2,2-difluoro-4-alkoxy-1,3,2-dioxaborinanes:: route to β-keto amides and β-enamino carboxamides

4-Alkoxy substituted 1,3,2-dioxaborinanes 1, readily available from b-keto esters, undergo substitution reactions under mild reaction conditions with primary and secondary amines, deriving the 4-alkylamino analogue 2. Reactions of 1 with substituted phenylhydrazines gave the corresponding hydrazones, or pyrazolones, and 5-alkoxy- 1H-pyrazoles as a mixture of products. (c) 2007 Elsevier Ltd. All rights reserved.