反应详情

5-n-butyl picolinic acid (1.8 g) and 3-fluoro-4-cyanophenol (1.4 g) were dissolved in methylene chloride (30 ml). While the resulting solution was kept at 0° C. or lower, a solution (20 ml) of dicyclohexylcarbodimide (2.1 g) in methylene chloride was dropped to the above solution, followed by further agitating for 3 hours, filtering off the resulting solids, adding 2N-NaOH aqueous solution to the filtrate, separating the methylene chloride layer, washing it with water till the washing water became neutral, distilling off the solvent from the methylene chloride layer and recrystallizing the residue from ethanol to obtain the objective 3-fluoro-4cyanophenyl 5-n-butylpicolinate (0.3 g) having a m.p. of 45.1°-46.1° C.

1. customwas kept at 0° C.
2. filtrationfiltering off the resulting solids
3. additionadding 2N-NaOH aqueous solution to the filtrate
4. customseparating the methylene chloride layer
5. washwashing it with water till the washing water
6. distillationdistilling off the solvent from the methylene chloride layer
7. customrecrystallizing the residue from ethanol