Triethylamine → 6-Chloro-N-(2-cyclopropylethyl)pyridazine-3-carboxamide

Participants

Reaction Steps

To a suspension of 6-chloropyridazine-3-carboxylic acid (4.1 g, 25.8 mmol) from Step 1 and DMF (50 μL) in CH2Cl2 (60 mL) at r.t. was added oxalyl chloride (5.0 mL, 57.1 mmol) and the mixture was refluxed for 30 min. Volatile materials were removed in vacuo to give the crude acid chloride as a pale yellow solid. The acid chloride was dissolved in CH2Cl2 (40 mL) and added to a solution of cyclopropylethylamine (2.4 g, 28.2 mmol) and Et3N (11 mL, 78 mmol) in CH2Cl2 at 0° C. over a period of about 15 min. After further stirring for 30 min, the mixture was diluted with more CH2Cl2, washed successively with 10% HCl, saturated aqueous NaHCO3, water, dried (Na2SO4) and concentrated. Chromatography over silica gel and elution with hexanes-EtOAc (2:1) gave the title compound as a white powder. 1H NMR (500 MHz, Acetone-d6): δ 0.12 (d, 2H), 0.47 (t, 2H), 0.80 (s, 1H), 1.57-1.61 (m, 2H), 3.58-3.62 (m, 2H), 8.02 (d, 1H), 8.31 (d, 1H), 8.62 (s, 1H).

Provenance & Evidence