摘要:
Ethyl 2-methylfuran-3-carboxylate is smoothly chloroethylated at 0 degrees C in the 5 position of the ring. The resulting halide alkylates secondary amines but eliminates HCl with sodium diethyl phosphite under the Michaelis-Becker reaction conditions and with trimethyl phosphite under the Arbuzov reaction conditions. In the reaction with sodium diethyl phosphite, small amounts of 5-[1-(diethoxyphosphoryl)ethyl]furan-3-carboxylate and 5-ethylfuran-3-carboxylate are formed. In the Arbuzov reaction at a 1 : 1.22 furan: trimethyl phosphite molar ratio, methyl 2,4-dimethyl-1-methoxy-1-oxo-l lambda(5)-1,2-dihydrophospheto[3,2-b]furan-5-carboxylate was isolated.