General procedure for the synthesis of methyl 6-fluoronicotinate: 6-fluoronicotinate (255 mg, 1.32 mmol) was dissolved in methanol (5 mL) at room temperature, followed by the addition of (trimethylmethylsilyl) diazomethane (4.0 mL, 2 M of ether solution, 8.0 mmol). The reaction mixture was stirred at room temperature for 30 min and then concentrated. The resulting methyl 6-fluoronicotinate (129 mg, 47% yield) was used without further purification. Its nuclear magnetic resonance hydrogen spectrum (1H NMR, 600 MHz, DMSO-d6) data were as follows: δ 8.79 (d, J=2.6 Hz, 1H), 8.47 (td, J=7.9,2.6 Hz, 1H), 7.35 (ddd, J=8.5,2.6,0.6 Hz, 1H), 3.88 (s, 3H). The calculated value for electrospray ionization mass spectrometry (ESIMS) was 156.0 (M++H) and the measured value was 156.1 (M++H).
