Ethyl 3-carbamoyl-4-chloropyrrolo[1,2-b]pyridazine-6-carboxylate → (R)-ethyl 4-((1-(tert-butoxycarbonyl)-3,3-dimethylpiperidin-4-yl)amino)-3-carbamoylpyrrolo[1,2-b]pyridazine-6-carboxylate

Participants

Reaction Steps

Following the conditions described in Step 2 of Example 1, ethyl 3-carbamoyl-4-chloropyrrolo[1,2-b]pyridazine-6-carboxylate (Intermediate 1, 0.7 g, 2.62 mmol,) was reacted with (R)-tert-butyl 4-amino-3,3-dimethylpiperidine-1-carboxylate (Intermediate 6, 0.657 g, 2.88 mmol) to give (R)-ethyl 4-((1-(tert-butoxycarbonyl)-3,3-dimethylpiperidin-4-yl)amino)-3-carbamoylpyrrolo[1,2-b]pyridazine-6-carboxylate (1.187 g, 99% yield). 1H NMR (400 MHz, chloroform-d) δ ppm 8.05 (d, J=1.8 Hz, 1H), 7.92 (s, 1H), 7.22 (d, J=1.5 Hz, 1H), 5.44 (br. s., 2H), 4.38 (q, J=7.1 Hz, 2H), 4.14-3.93 (m, J=9.6, 9.6, 3.7 Hz, 2H), 3.73 (br. s., 1H), 3.14 (br. s., 1H), 2.89 (br. s., 1H), 2.09-2.00 (m, 1H), 1.84-1.72 (m, 1H), 1.49 (s, 9H), 1.40 (t, J=7.2 Hz, 3H), 1.11 (s, 3H), 1.03 (s, 3H); MS (ES+) m/z: 460.3 (M+H); LC retention time: 4.250 min (analytical HPLC Method H).

Provenance & Evidence