Cesium fluoride → Methyl 4-amino-3-chloro-6-(4-cyclopropylphenyl)-5-fluoropicolinate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Ethyl 4-amino-3-chloro-6-(4-cyclopropylphenyl)-5-fluoropicolinate. 4-Cyclopropylphenylboronic acid (250 mg, 1.5 mmol, 1.2 equiv) and methyl 4-amino-3,6-dichloro-5-fluoropicolinate (300 mg, 1.3 mmol, 1.0 equiv) were sequentially added to a 5 mL Biotage microwave vessel, followed by CsF (380 mg, 2.5 mmol, 2.0 equiv), palladium(II) acetate (14 mg, 0.063 mmol, 0.05 equiv), and sodium 3,3′,3″-phosphinetriyl-tribenzenesulfonate (71 mg, 0.13 mmol, 0.10 equiv). A 3:1 mixture of water-acetonitrile (2.5 mL) was added, and the resulting brown mixture was heated in a benchtop microwave at 150° C. for 5 min. The cooled reaction mixture was diluted with water (150 mL) and extracted with CH2Cl2 (4×50 mL). The combined organic extracts were dried (MgSO4), gravity filtered, and concentrated by rotary evaporation. The residue was purified by RP-HPLC (eluting with a 5% acetonitrile to 100% acetonitrile gradient) to afford the desired product, methyl 4-amino-3-chloro-6-(4-cyclopropylphenyl)-5-fluoropicolinate as a white powder (310 mg, 78%): mp 116-119° C.; IR (thin film) 3475 (s), 3357 (s), 3089 (w), 3013 (w), 2954 (w), 1724 (m), 1607 (m) cm−1; 1H NMR (300 MHz, CDCl3) δ 7.81 (m, 2H), 7.15 (m, 2H), 4.85 (br s, 2H), 3.98 (s, 3H), 1.94 (m, 1H), 1.01 (m, 2H), 0.74 (m, 2H); ESIMS m/z 321 ([M+H]+).

Herkunft & Nachweise