How is Amino(5-methyl-2-thienyl)acetic acid (CAS: 89776-66-9) typically synthesized?

Amino(5-methyl-2-thienyl)acetic acid can be synthesized through a multi-step process involving the preparation of the 5-methylthiophene derivative, followed by acylation with an acyl chloride or anhydride. The reaction is catalyzed by a Lewis acid and proceeds with good yield and selectivity. Commonly used catalysts include aluminum chloride or thionyl chloride. The final step involves the nucleophilic substitution of the chloride with ammonia to form the amino derivative.