Diisopropylethylamine → (R)-4-(1-(1-fluorocyclopropyl)ethylamino)pyrrolo[1,2-b]pyridazine-3-carboxamide

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Reaction Steps

A solution of 4-chloropyrrolo[1,2-b]pyridazine-3-carboxamide (Preparation 3, 20 mg, 0.102 mmol), (R)-1-(1-fluorocyclopropyl)ethanamine hydrochloride (22 mg, 0.153 mmol), and diisopropylethylamine (0.054 mL, 0.31 mmol) in NMP (0.5 mL) was heated to 120° C. for 10 min in the CEM microwave. The mixture was cooled to rt, diluted with MeOH and purified by reverse-phase Prep HPLC (condition A). The fraction containing the major product was concentrated on the rotovap to remove the MeOH and the aqueous slurry of the product was neutralized by addition of ˜1 mL of saturated aqueous sodium bicarbonate. Sonication of the slurry followed by vacuum filtration and air drying in the funnel afforded 4 mg (14%) of a pale yellow solid as the title compound. HPLC (condition B): retention time=3.26 min. LCMS (condition B): MH+ m/z 263.2. 1H NMR (500 MHz, MeOD) δ ppm 8.17 (1 H, s), 7.64 (1 H, dd, J=2.64, 1.53 Hz), 7.27 (1 H, dd, J=4.44, 1.39 Hz), 6.74 (1 H, dd, J=4.44, 2.77 Hz), 5.07 (1 H, br. s.), 1.37-1.56 (3 H, m), 1.01-1.37 (4 H, m).

Provenance & Evidence