Aminophosphonocarboxylates of the Furan Series

Halomethyl derivatives of (diethoxyphosphorylmethyl)furan-2(3)-carboxylates containing blocking methyl group in the position 5 of the furan ring were synthesized. In the course of constructing of carbon skeleton of these compounds it was found that alkyl 3-methoxymethyl-, 3-chloromethyl-, and 3-(diethoxyphosphorylmethyl)-5-methyl-2-furoates are halomethylated at elevated temperature in the position 4 of the furan ring. No ring destructure or transformation of the side chain of substituents was observed. The obtained halomethylfurans and their tert-butyl analogs by treating with sodium azide in acetonitrile were converted to corresponding azides. The reduction of latter with triphenylphosphine in ethanol led to formerly unavailable aminophosphonocarboxylates of the furan series.