Ethyl Acrylate → Ethyl (2E)-3-(6-aminopyridin-3-yl)prop-2-enoate

Participants

Reaction Conditions

Reaction Steps

To a glass bomb were charged with 5-bromopyridin-2-amine (10.0 g, 57.8 mmol), ethyl acrylate (8.14 mL, 75 mmol) and DIEA (25.2 mL, 144 mmol) in DMF (40 mL). The mixture was purged with argon, followed by addition of Pd(OAc)2 (0.649 g, 2.89 mmol) and (o-Tol)3P (3.87 g, 12.72 mmol), and finally purged thoroughly with argon. The mixture was sealed, and heated with 100° C. oil bath overnight. The reaction mixture was cooled down to room temperature, and the precipitates were removed by filtering through a thin layer of Celite. The filtrate was concentrated as much as possible via rotavap, and the residue was partitioned between EtOAc/water (150 mL/100 mL). EtOAc layer was washed with water (2×100 mL), dried over Na2SO4, and concentrated. A brown slid was obtained as crude product. The crude product was triturated with EtOAc (40 mL) and the yellow solid was collected via filtration. The filter cake was rinsed with small amount of EtOAc and dried under vacuum as the first crop of product (5.0 g). The mother liquor from trituration was stripped by dilute aqueous 1 N HCl (30 mL) and water (70 mL). Aqueous layer was transferred to a clean separate funnel, basicified with 20 mL sat. Na2CO3, and extracted with EtOAc (60 mL). EtOAc layer was dried over Na2SO4, concentrated and provided the second portion of product (4.0 g). The two crops of product were combined to afford 81% yield. LCMS (m/z) 193.2 (MH+), 0.39 min.

Provenance & Evidence