Pyridine,3,5-dichloro-4-ethoxy-2-fluoro-(9CI) synthesis

Yield:-

Reaction Conditions:

with sodium ethanolate in ethanol;water;mineral oil;

Steps:

17 17.

17. Preparation of 3,5-Dichloro-4-ethoxy-2-fluoropyridine To a solution of 70.2 g (0.38 mol) of 3,5-dichloro-2,4-difluoropyridine in 600 mL of ethanol was slowly added with stirring a solution of sodium ethoxide in ethanol prepared from 16 g (0.40 mol) of sodium hydride (60 percent in mineral oil, hexane washed) in 200 mL of ethanol. The mixture was allowed to stir overnight and the brown solution obtained was filtered through powdered cellulose and concentrated by evaporation under reduced pressure. The residue was partitioned between 500 mL of ether and 400 mL of water. The organic phase was recovered, dried over magnesium sulfate, filtered, and concentrated by evaporation. The residue was distilled to obtain 62 g (84 percent of theory) of the title compound as a colorless oil having a boiling point of 175°-180° C. at 0.4 mm Hg (53 Pascals). Elemental Analysis C₇ H₆ Cl₂ FN Calc.: %C, 43.3; %H, 3.12; %N, 7.22 Found: %C, 40.0; %H, 2.92; %N, 6.66. ¹ H NMR (CDCl₃): 8.04 (s, 1H); 4.3 (q, 2H, j=7.0); 1.48 (t, 3H, j=7.1).

References:

US5614469,1997,A