Phosphonomethylated acetoxymethyl derivatives of acetylfurans and alkyl furoates with the remote location of substituents: synthesis and further transformations

Abstract

Methods of synthesis of phosphonomethylated acetoxymethyl derivatives of acetylfurans and alkyl furoates with the remote location of functional groups were developed. Investigation of methanolysis of these compounds in presence of sodium methylate showed that complete transesterification of acetates is achived when the equimolar amount of base is used. It takes place due to high acidity of furan alcohols. If acetoxymethyl group is located in the position 3 of the furan ring, and diethoxyphosphorylmethyl one - in the position 2, cleavage of P-C bond takes place. If phosphonomethyl group is located in the position 3, and acetoxymethyl one occupies position 2 or 4, transesterification of ester groups of phosphonate takes place, but P-C bond is not touched. The ester group of carbonic acid is transesterified in any case. The alcohols formed are oxidized according to Kollins to give the corresponding aldehydes. 2-Furylbenzo[ d ]thiazole having ester and diethoxyphosphorylmethyl groups in the furan ring was synthesized by reacting methyl 2-(diethoxyphosphorylmethyl)-5-formylfuran-3-carboxylate with 2-aminothiophenol.