How is Disodium 5-acetamido-4-hydroxy-3-[(E)-phenyldiazenyl]-2,7-naphthalenedisulfonate (CAS: 3734-67-6) typically synthesized?

Disodium 5-acetamido-4-hydroxy-3-[(E)-phenyldiazenyl]-2,7-naphthalenedisulfonate is typically synthesized via a multi-step process involving diazotization, acetylation, and sulfonation reactions. The key steps include the diazotization of a naphthalene derivative, subsequent acetylation, and sulfonation, which are carried out under controlled conditions to ensure high yield and selectivity. The reaction is usually performed in a fume hood and requires specific catalysts and solvents.