2,6-Bis(4′-azidobenzylidene)-4-methylcyclohexanone5284-79-7100 % similar 4-Azidobenzoic acid6427-66-338 % similar P-Azido-L-phenylalanine33173-53-437 % similar 2,6-Dibenzylidenecyclohexanone897-78-934 % similar