How is 4-(2,3-Dichlorophenyl)-2,6-dimethyl-1,4-dihydro-3,5-pyridinedicarboxylic acid (CAS: 138279-32-0) typically synthesized?

4-(2,3-Dichlorophenyl)-2,6-dimethyl-1,4-dihydro-3,5-pyridinedicarboxylic acid is synthesized through the condensation of 2,3-dichloroaniline and adipic acid. The synthesis typically involves multi-step reactions and requires careful control of temperature and pH. Catalysts such as p-toluenesulfonic acid (p-TSA) are used to increase the reaction rate and yield. The final product is isolated by crystallization from an appropriate solvent.