Synthesis of Aminopyrazoles from α-Oxoketene O, N-Acetals Using Montmorillonite K-10/Ultrasound

…, DM Henriques, L de Carvalho Tavares

Index: Braibante, Mara E. F.; Braibante, Hugo T. S.; Da Roza, Juliano K.; Henriques, Danielle M.; De Carvalho Tavares, Luciana Synthesis, 2003 , # 8 p. 1160 - 1162

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Citation Number: 12

Abstract

The procedure for the condensation of the primary amines with β-oxothioxo esters for the synthesis of α-oxoketene O,N-acetals has been reported in the literature. [17] The regiochemistry of these reactions shows strong dependence on the reaction medium and reaction conditions. When the reaction is carried out with formic acid under reflux in toluene, β-oxothioxo esters are obtained. Without formic acid, a mixture of α-oxoketene O,N-acetals and enaminothio ...