Used as a key intermediate in the synthesis of pharmaceuticals, particularly in the development of isoquinoline-based bioactive compounds. Its aldehyde and chlorine functional groups allow for selective reactions, enabling the construction of complex heterocyclic systems. Commonly employed in antitumor, antimicrobial, and anti-inflammatory drug research due to the pharmacological relevance of substituted isoquinolines. Also utilized in agrochemicals for designing novel pesticides with improved efficacy and selectivity.