Sulfuric Acid → Methyl 4-amino-6-(4-chlorophenyl)-5-fluoropicolinate

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 6-(4-chlorophenyl)-5-fluoro-4-((4-oxocyclohexa-2,5-dien-1-ylidene)amino)picolinate (0.074 g, 0.20 mmol) and 0.1 M H2SO4 (0.2 mL) in a 1:1 mixture of CH3CN/H2O (2 mL) was heated to 80° C. for 1 h. After stirring at room temperature for 2 h, the reaction mixture was added to CH2Cl2 (10 mL). The organic layer was washed with a saturated solution of NaCl and dried (MgSO4), and the solvent was removed. Preparative TLC on silica gel eluting with 20% EtOAc/hexane gave methyl 4-amino-6-(4-chlorophenyl)-5-fluoropicolinate (0.050 g, 0.169 mmol, 85% yield) as a light yellow solid: 1H NMR (400 MHz, CDCl3) δ 7.83 (m, 2H), 7.45 (d, J=6.2 Hz, 1H), 7.37 (m, 2H), 4.40 (br s, 2H), 3.90 (s, 3H). ESIMS m/z 279.77 ([M−H]−); 19F NMR (376 MHz, CDCl3) δ −145.11.

Provenance & Evidence