An efficient three-component synthesis of 3-(1,3,4-oxadiazol-2-yl)-3-hydroxy-1,3-dihydro-2H-indol-2-ones is described. A mixture
of N-isocyaniminotriphenylphosphorane,
an isatin, and a carboxylic acid undergoes a 1:1:1 addition reaction
under mild conditions to afford the title compounds in excellent
yields.
N-isocyaniminotriphenylphosphorane - isatins - carboxylic acids - 1,3,4-oxadiazoles - multi-component reactions - heterocycles - cyclizations