How is 3-Amino-4-methoxybenzenesulfonic acid (CAS: 98-42-0) typically synthesized?

3-Amino-4-methoxybenzenesulfonic acid (CAS: 98-42-0) can be synthesized via the sulfonation of 4-methoxyaniline followed by coupling with benzenesulfonyl chloride. The reaction typically involves the use of a phase transfer catalyst and requires careful control of the reaction conditions to achieve high yield and selectivity. The overall process is moderately complex but straightforward for experienced chemists.