Hydrochloric Acid → Pentoxazone

Participants

Reaction Conditions

Reaction Steps

Ethyl N-(4-chloro-5-cyclopentyloxy-2-fluorophenyl)carbamate (3.01 g, 10 mmol), ethyl 2-hydroxy-3-methyl-3-butenoate (2.16 g, 15 mmol) and tetrabutylammonium chloride (278 mg, 1.0 mmol) were introduced into a flask (25 cc) equipped with a distillation unit, and the reaction was conducted at 200° C. for 1.5 hours. After completion of the reaction, the reaction solution was allowed to cool to 70 to 80° C., and a mixed solution consisting of methanol (5 mL) and 6N hydrochloric acid (0.25 mL) was added thereto and mixed homogeneously. Then, the reaction solution was left to stand at room temperature. The precipitated solid was collected by filtration, washed with a mixed solution consisting of methanol (8 mL) and 6N hydrochloric acid (0.4 mL) and then water (10 mL) and dried completely under reduced pressure to obtain 3-(4-chloro-5-cyclopentyloxy-2-fluorophenyl)-5-isopropylidene-1,3-oxazolidine-2,4-dione (1.30 9, yield 36.7%).

Provenance & Evidence