Transesterification of Methyl 2‐Nitroacetate to Superior Esters

Abstract

Methyl 2‐nitroacetate and methyl acetoacetate have in common the presence of an electron‐withdrawing substituent geminal to the methyl ester function but the well‐known ease of thermal transesterification of methyl acetoacetate has not been found in methyl 2‐nitroacetate. The latter gives uncatalysed thermal transesterification only in low yield and at a temperature higher than that of methyl acetoacetate. Comparative experiments provided further insight into the reactions; protic and Lewis acid catalysts promoted the smooth exchange of the alkanoyl groups, observing first the transesterification of methyl 2‐nitroacetate with ethanol, already proved difficult to proceed. Dibutyltin(IV)oxide (DBTO) catalyst offered the spur to set up a convenient synthetic methodology from methyl 2‐nitroacetate, encompassing higher molecular weight and functionalised alcohols: aliphatic, unsaturated and oxidation sensitive species were suited to react, delivering the corresponding 2‐nitroacetate esters in good yields in most cases.