Can any one suggestion for synthesis oxadiazole from reaction 4-hydroxy benzoyl hydrazine with dimethyl dichlorosilane then react it with appropriate 4-alkoxybenzoicacid and phosphorus oxychloride to synthesis 1,3,4-oxadiazole.
Pretty much any silyl ether will work well as a phenol protecting group (Si-O bond is much stronger than Si-N, so you should be able to selectively protect it.) Not sure you'd want a residual Si-Cl bond, though . . . it could react with the -NH2, and if it does you'd get a linear polymer.