1,3-Dichloro-5,5-dimethylhydantoin → Methyl 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)-5-fluoropicolinate

Beteiligte Stoffe

Reaktionsschritte

A mixture of methyl 4-amino-5-fluoro-6-(4-chloro-2-fluoro-3-methoxyphenyl)-picolinate (0.5 g, 1.52 mmol) and 1,3-dichloro-5,5-dimethylimidazolidine-2,4-dione (0.30 g, 1.52 mmol) in acetonitrile (10 mL) was heated to reflux for 1.5 h. Upon cooling to room temperature, the reaction mixture was concentrated under vacuum and then purified by silica gel chromatography (100% hexane to 100% EtOAc gradient) to give a light brown solid (0.53 g, 100%): mp 169-170.5° C.; 1H NMR (400 MHz, DMSO-d6) δ 7.48 (d, J=8.4 Hz, 1H), 7.32 (t, J=7.7 Hz, 1H), 7.15 (s, 2H), 3.96 (s, 3H), 3.90 (s, 3H). 13C NMR (101 MHz, DMSO-d6) δ 164.8 (s), 153.1 (d, J=253 Hz), 146.3 (s), 144.5 (d, J=4 Hz), 143.7 (s), 142.8 (dd, J=227, 14 Hz), 136.4 (d, J=13 Hz), 128.6 (d, J=3 Hz), 125.9 (s), 125.5 (d, J=4 Hz), 122.9 (dd, J=14, 4 Hz), 113.0 (d, J=3 Hz), 61.6 (d, J=4 Hz), 52.7 (s). Anal. Calcd for C14H10Cl2F2N2O3: C, 46.30; H, 2.78; N, 7.71. Found: C, 46.60; H, 2.68; N, 7.51.

Herkunft & Nachweise