Methyl iodide → (R)-tert-butyl 4-((3-carbamoyl-6-(5-(methylthio)-1,3,4-oxadiazol-2-yl)pyrrolo[1,2-b]pyridazin-4-yl)amino)-3,3-dimethylpiperidine-1-carboxylate

Participants

Reaction Steps

A solution of (R)-tert-butyl 4-((3-carbamoyl-6-(hydrazinecarbonyl)pyrrolo[1,2-b]pyridazin-4-yl)amino)-3,3-dimethylpiperidine-1-carboxylate (380 mg, 0.853 mmol) and di(1H-imidazol-1-yl)methanethione (175 mg, 0.981 mmol) in tetrahydrofuran (10 mL) was stirred at room temperature for 10 min then heated to reflux for 100 min. After cooling to room temperature, triethylamine (0.357 mL, 2.56 mmol) and iodomethane (0.107 mL, 1.706 mmol) were added. The resulting mixture was stirred at room temperature for 5 h. The tetrahydrofuran solvent was evaporated in vacuo. The residue was triturated with water. The solid product was collected by filtration to give (R)-tert-butyl 4-((3-carbamoyl-6-(5-(methylthio)-1,3,4-oxadiazol-2-yl)pyrrolo[1,2-b]pyridazin-4-yl)amino)-3,3-dimethylpiperidine-1-carboxylate as white solid (0.404 g, 94% yield). 1H NMR (400 MHz, chloroform-d) δ ppm 10.78 (d, J=8.4 Hz, 1H), 8.10 (d, J=1.8 Hz, 1H), 7.94 (s, 1H), 5.50 (br. s., 2H), 4.01 (dd, J=9.4, 5.8 Hz, 2H), 3.72 (br. s., 1H), 3.18 (br. s., 1H), 2.91 (br. s., 1H), 2.80 (s, 3H), 2.06 (d, J=14.3 Hz, 1H), 1.89-1.75 (m, 1H), 1.49 (s, 9H), 1.12 (s, 3H), 1.05 (s, 3H); MS (ES+) m/z: 502.3 (M+H); LC retention time: 4.241 min (analytical HPLC Method H).

Provenance & Evidence