Sodium Carbonate → 8-(2,4-Difluorophenyl)-1-methyl-2-oxo-1,2-dihydropyrido[3,2-d]pyridazine-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a suspension of ethyl 8-chloro-1-methyl-2-oxo-1,2-dihydropyrido[3,2-d]pyridazine-3-carboxylate (6) (1.40 g, 5.23 mmol) in 3:1 1,4-dioxane: 2 M aq Na2CO3 (16 mL) was added 2,4-difluorophenylboronic acid (1.03 g, 6.54 mmol) and tetrakis(triphenylphosphine)palladium (0) (0.484 g, 0.418 mmol). The reaction mixture was heated in a microwave at 100° C. for 75 min, then more Na2CO3 solid (100 mg) was added and the reaction mixture was heated in the microwave at 100° C. for an additional 2 h. The mixture was diluted with water and washed with CH2Cl2. The aqueous layer was then acidified with 5 N HCl to pH ˜2 and extracted with CHCl3/iPrOH (4:1). The combined organic extracts were dried over MgSO4, filtered, and concentrated in vacuo to give 8-(2,4-difluorophenyl)-1-methyl-2-oxo-1,2-dihydropyrido[3,2-d]pyridazine-3-carboxylic acid as a brown solid. MS (ESI, pos. ion) m/z: 318 (M+1).

Provenance & Evidence