Phosphorus oxychloride → 4-Chloro-1,5-dimethyl-6-oxo-1,6-dihydropyridazine-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-hydroxy-1,5-dimethyl-6-oxo-1,6-dihydropyridazine-3-carboxylic acid (876 mg, 4.76 mmol) and POCl3 (4.5 mL) was heated for 24 hours at 85° C. POCl3 was removed under reduced pressure. The crude material was quenched with ice. The reaction mixture was stirred for 1 hour at room temperature. After removing solids by filtration, the aqueous filtrate was extracted with EtOAc (3×). The combined organic layers were dried over MgSO4, filtered, and concentrated under reduced pressure to give. The recovered material was combined with the solids previously isolated and triturated with ether to afford 577 mg (60%) of the desired product.

Provenance & Evidence