Synthesis and Selected Reactions of 2(3)-Furoyl Phosphonates Functionalyzed at the Neighbor Position of the Furan Ring

Abstract

Reactions of 2-and 3-furoyl chlorides having chloromethyl or butylthiomethyl group in the adjacent position of the furan ring as well as of analogous N-morpholinomethylfuroyl chloride hydrochlorides with triethyl phosphite have been studied. The synthesized chloromethylfuroyl phosphonates have given the corresponding products of nucleophilic substitution in the reactions with sodium azide and potassium thiocyanate in the case of 4-chloromethyl-3-furoyl phosphonate. In the reaction of 3-chloromethyl-2-furoyl phosphonate with sodium azide, cleavage of the P-C bond takes place simultaneously with nucleophilic substitution. Potassium thiocyanate forms 3-thiocyanatomethyl-2-furoyl phosphonate in the reaction with this substance. The synthesized stable furoyl phosphonates enter the Wittig reaction with resonance-stabilized phosphoranes to give phosphorylated furylalkenes. If these compounds carry a chloromethyl group in the furan ring, they react with sodium azide and potassium thiocyanate to give the corresponding products of nucleophilic substitution. Analogously, aminomethyl derivatives have been obtained in the reaction with morpholine at room temperature.