Isoxal ,Shionogi, Japan ,1979
ChEBI: Perisoxal citrate is a carbonyl compound.
Crude crystals of 3-(2-methylthio-2-piperidinoacetyl)-5-phenilisoxazole (1.631 g) are suspended in 20 ml of methanol without being further purified and the suspension is stirred after a portionwise addition (in about 10 minutes) of 143 mg (3.78 mmol) of sodium borohydride at room temperature for about 30 minutes.
The methanol in the reaction mixture (pale yellow solution) is then removed by evaporation under reduced pressure to leave a residue which is subsequently dissolved in 30 ml of benzene. The benzene solution is shaken four times with 20 ml of 4 N hydrochloric acid each time to extract the basic substance. Each of the hydrochloric acid layers is washed once with 20 ml of benzene and combined together to be neutralized with potassium carbonate while being ice-cooled until it becomes basic (pH = 10).
The liberated crystalline substance is extracted twice with 50 ml of dichloromethane each time. After being separated, the dichloromethane layers are combined and washed once with 30 ml of water and dried over sodium sulfate. The solvent of the layer is removed by evaporation under reduced pressure to leave a crystalline residue (72.56 mg, 53% crude yield).
Recrystallization of this product from dichloromethane-ether (1:4) affords needles of 3-(2-piperidino-1-hydroxyethyl)-5-phenylisoxazole (701 mg, 51.3% as an overall yield calculated based on the starting material, melting point 104°C to 106°C. The product thus obtained may be reacted with citric acid to give the citrate.
Antiinflammatory, Analgesic
Poison by subcutaneous and intravenous routes. Moderately toxic by ingestion. When heated to decomposition it emits toxic fumes of NOx.
