Dichloromethane → tert-Butyl 4-(5-(6-amino-5-chloropyrazin-2-yl)pyridin-2-yl)piperazine-1-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a mixture of 6-bromo-3-chloropyrazin-2-amine (2.00 g, 9.60 mmol), tert-butyl 4-(5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-2-yl)piperazine-1-carboxylate (3.74 g, 9.60 mmol), Cs2CO3 (7.82 g, 24.0 mmol), and Pd(dppf)2.CH2Cl2 (786 mg, 0.959 mmol) in 1,4-dioxane (40 mL) was added water (20 mL). The resulting mixture was stirred at 90° C. for 16 h and then cooled to rt. The reaction mixture was diluted with EtOAc (300 mL), then washed with water (2×50 mL) and brine (50 mL). Removal of the solvent under reduced pressure followed by purification by flash column chromatography on silica gel (0-3% MeOH/DCM) gave compound 87a as a yellow solid. 1H-NMR (CDCl3; 400 MHz) δ 8.75 (d, J=2.2 Hz, 1H), 8.01-8.09 (m, 2H), 6.70 (d, J=9.0 Hz, 1H), 5.02 (br. s., 2H), 3.60-3.69 (m, 4H), 3.57 (br. s., 4H), 1.49 (s, 9H). Mass spectrum (LCMS, ESI pos.): Calcd. for C18H23ClN6O2, 391.1 (M+H). found 391.1.

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