How is 3,6-Dichloro-4-pyridazinecarboxylic acid (CAS: 51149-08-7) typically synthesized?

3,6-Dichloro-4-pyridazinecarboxylic acid is typically synthesized via the reaction of 4-chloropyridazine with chloroacetyl chloride followed by hydrolysis. The synthesis involves a series of steps that include chlorination and acylation. The yield of the final product is around 85-90%, and the reaction is selective, with minimal by-products. Suitable catalysts and solvents are used to enhance the reaction selectivity and yield.