Preparation of 5-substituted 3-aminofuran-2-carboxylate esters

GRAPHICS An efficient method for the preparation of 3-aminofuran-2-carboxylate ester s has been developed. This method is based on the reaction of an alpha-cyan oketone with ethyl glyoxylate under Mitsunobu conditions to produce a vinyl ether in good yield. Subsequent treatment of the vinyl ether with sodium h ydride afforded the 3-aminofuran, It was also found that a one pot procedur e using the Mitsunobu reaction followed by cyclization afforded the 3-amino furan in comparable yield. Currently, this method is limited to the synthes is of 5-alkyl-, 5-aryl-, and 4,5-fused bicyclic furans.