Potassium Phosphate, Tribasic → (3S,4S)-benzyl 3-((3-carbamoyl-6-(6-((2-methoxyacetamido)methyl)pyridin-3-yl)pyrrolo[1,2-b]pyridazin-4-yl)amino)-4-ethylpyrrolidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 180 mg (0.370 mmol) of (3S,4S)-benzyl 3-((6-bromo-3-carbamoylpyrrolo[1,2-b]pyridazin-4-yl)amino)-4-ethylpyrrolidine-1-carboxylate (prepared by coupling Intermediate 2 and Intermediate 9 using the method described in Step 1 of Example 52), (6-((2-methoxyacetamido)methyl)pyridin-3-yl)boronic acid (332 mg, 1.480 mmol), potassium phosphate, tribasic, 2M (0.925 mL, 1.850 mmol) and PdCl2(dppf) (54.2 mg, 0.074 mmol) in DMA (2.5 mL) was stirred at 90° C. for 45 minutes. After cooling to rt, the reaction mixture was diluted with ˜40 ml of EtOAc. The resulting dark mixture was filtered through celite and the filtrate was washed with water (40 ml), 10% LiCl solution (2×40 ml) and brine (40 ml). After drying (MgSO4) and filtration, the organic layer was concentrated to a brown oil that was chromatographed on a 4 gm ISCO silica gel cartridge, eluting with a 0-100% EtOAc/Hex gradient, followed by a 0-10% MeOH/CH2Cl2 gradient. The pure fractions were concentrated to afford a brown oil that was triturated with ethyl ether. Filtration and drying afforded (3S,4S)-benzyl 3-((3-carbamoyl-6-(6-((2-methoxyacetamido)methyl)pyridin-3-yl)pyrrolo[1,2-b]pyridazin-4-yl)amino)-4-ethylpyrrolidine-1-carboxylate (203 mg, 0.347 mmol, 94% yield) as a tan solid. The material will be used as is in the next step. MS (ES+) m/z: 586.3 (M+H); LC retention time: 2.388 min (analytical HPLC Method O).

Provenance & Evidence