Pyrolysis of hydrazonodihalomethanes of type (RO&) zNN= CXt (R= Me, Et; X= C1, Br) resulted in forma-tion, in high yield, of alkyl 5-halo-2-oxo-A4-1, 3, 4-oxadiazoline-3- carboxylates. A different mode of decomposition was observed when R= Ph. The reaction of PhHgCXzBr (X= C1 and Br) with azodibenzoyl gave the respective benzoyl halide and 2- halo-5-phenyl-1, 3, 4-oxadiazole in a reaction that may have involved initial l, $-addition of ...
