Patent ID: 9309192
Filing Date: 2016-04-12
CPC Classification: C07C

Claim Text:
1. A method for preparing 3,5-bis(cyanato)benzoate esters, comprising: preparing a mixture 3,5-dihydroxybenzoic acid and at least one amine; heating said mixture in the presence of an acid catalyst; purifying said 3,5-dihydroxybenzamide (III) from said mixture: treating (III) with cyanogen halide in the presence of at least one base and one solvent; isolating said 3,5-bis(cyanato)benzamide (IV) from said treated (III): Rt and R2 are each 1-30 carbons; and purifying said 3,5-bis(cyanato)benzamide (IV) to attain a cyanate ester monomer capable of forming thermally cured resins.