Potassium Carbonate → 2,4-Oxazolidinedione, 3-(4-chloro-2-fluoro-5-((1-methyl-2-propyn-1-yl)oxy)phenyl)-5-(1-methylethylidene)-

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Reaction Steps

Acetonitrile (50 ml) was added to a mixture comprising N-(2-fluoro-4-chloro-5-hydroxyphenyl)-5-isopropylidene-1,3-oxazolidine-2,4-dione (5.0 g, 15.7 mmol), 1-butyn-3-yl p-toluenesulfonate (4.0 g, 17.8 mmol) and potassium carbonate (1.5 g, 10.9 mmol), and the reaction mixture was heated for 4 hours under reflux. After reaction, acetonitrile was removed by distillation under reduced pressure, and 1 N hydrochloric acid (100 ml) was added to the residue, which was then extracted with ether (50 ml ×2). After dried, ether was removed by distillation under reduced pressure, and an oily product of 3N-{2-fluoro-4-chloro-5-(1-butyn-3-yl)oxyphenyl}-5-isopropylidene-1,3-oxazolidine-2,4-dione was obtained. This was recrystallized from ether/hexane, and a pure product (4.94 g, 14.6 mmol) was obtained. Yield: 83.6 %. Spectral and other data of the product are those as shown in Example 30.

Provenance & Evidence