Preparation and thermal curing of single-ring bis(cyanate) ester monomers

A method for preparing 3,5-bis(cyanato)benzoate esters, comprising:

• reacting 3,5-di(benzyloxy)benzoic acid with oxalyl chloride;
• treating said acid/chloride with an aliphatic and/or aromatic alcohol (ROH), wherein R is an aliphatic and/or aromatic component of said aliphatic and/or aromatic alcohol, in the presence of a base to form (V):
• dissolving said (V) in at least one solvent, adding a solid catalyst and hydrogen gas, and reacting by stirring for about 2 to about 48 hours;
• removing of said catalyst by filtration and solvents by evaporation forming 3,5-dihydroxybenzoate ester (I);
• purifying said 3,5-dihydroxybenzoate ester (I);
• treating said 3,5-dihydroxybenzoate ester (I) with cyanogen halide in the presence of at least one base and at least one solvent forming 3,5-bis(cyanato)benzoate ester (II);
• isolating said 3,5-bis(cyanato)benzoate ester (II):
• and
• purifying said 3,5-bis(cyanato)benzoate ester (II) to attain a cyanate ester monomer capable of forming thermally cured resins.