5-[(4-methoxyphenyl)methylidene]-1,3-thiazolidine-2,4-dione

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 5-[(4-Methoxyphenyl)methylidene]thiazolidine-2,4-dione (6.00 g, 25.5 mmol), 10% palladium on carbon (6.00 g) and a mixed solvent of tetrahydrofuran and ethanol (2:1 v/v, 300 mL) were mixed, and hydrogenation was performed at room temperature and at an initial pressure of 294 kPa. After completion of the reaction, catalyst was filtered and the filtrate was concentrated. The residue was purified by silica gel chromatography (eluate n-hexane: ethyl acetate=2:1 v/v) to obtain 5.84 g (97%) of the title compound as colorless powder. was performed at room temperature After completion of the reaction, catalyst was filtered the filtrate was concentrated The residue was purified by silica gel chromatography (eluate n-hexane: ethyl acetate=2:1 v/v)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-Methoxybenzaldehyde (20.4 g, 150 mmol), thiazolidine-2,4-dione (21.1 g, 180 mmol), piperidine (12.8 g, 150 mmol) and ethanol (150 mL) were mixed and refluxed for 18 hours. After allowed to stand for cooling, the precipitated crystals were collected by filtration. These were washed with ethanol, and then dried to obtain 11.2 g (32%) of the title compound as yellow crystals. Moreover, the filtrate was made acidic with concentrated hydrochloric acid, and the precipitated crystals were collected by filtration, washed with ethanol and water, and then dried to additionally obtain 18.1 g (51%, totally 83%) of the title compound as yellow crystals. refluxed for 18 hours for cooling the precipitated crystals were collected by filtration These were washed with ethanol dried

Conditions: temp:0.00; pressure:0.00; stir: