Crystalline form of ethyl 2-[2-[2-chloro-4-fluoro-5-[3-methyl-2,6-dioxo-4-(trifluoromethyl)pyrimidin-1-yl]phenoxy]phenoxy]acetate

A crystalline form A of ethyl 2-[2-[2-chloro-4-fluoro-5-[3-methyl-2,6-dioxo-4-(trifluoromethyl)-pyrimidin-1-yl]phenoxy]phenoxy]acetate, which in an X-ray powder diffraction diagram at 25° C. and Cu-Kc radiation displays at least 3 of the following reflections, quoted as 2θ values:

• 10.0±0.2°, 11.2±0.2°, 11.5±0.2°, 11.9±0.2°, 12.6±0.2°, 14.4±0.2°, 15.3±0.2°, 16.3±0.2°, 17.6±0.2°, 18.1±0.2°, 19.0±0.2°, 19.2±0.2°, 20.3±0.2°, 20.9±0.2°, 21.5±0.2°, 21.9±0.2°, 22.4±0.2° 23.0±0.2°, 24.4±0.2°, 24.7±0.2°, 25.3±0.2°, 26.1±0.2°, and 29.1±0.2°.