Feclobuzone

Originator

Feclobuzone,Shanghai Lansheng

Definition

ChEBI: Feclobuzone is a benzoate ester.

Manufacturing Process

a) Preparation of 1,2-diphenyl-4-n-butyl-3-hydroxy-methyl-3,5- dioxopyrazolidine:
308 g (1 mole) of 1,2-diphenyl-4-n-butyl-3,5-dioxo-pyrazolidine are refluxed during 2 hours in a mixture of 900 ml absolute ethanol and 100 ml of a solution of formaldehyde 40% in water. The mixture is allowed to cool overnight in a refrigerator and after filtration, washing with alcohol and drying; crystals (305 g) are obtained. Melting point: 146-147°, yield 90%.
b) Preparation of para-chlorobenzoic ester of 1,2-di-phenyl-4-n-butyl-4- hydroxymethyl-3,5-dioxopyrazolidine:
In a 2 liter 3-necked flask fitted with mechanical stirrer, dropping funnel and entry for nitrogen circulation, 338 g (1 mole) of the 1,2-diphenyl-4-n-butyl-3- hydroxy-methyl-3,5-dioxopyrazolidine are added. The resultant mixture is dissolved in a mixture of 200 ml pyridine and 600 ml dimethylformamide. When the temperature reaches 0°C, 175 g (1 mole) of p-chlorobenzyl chloride previously subjected to a mild nitrogen flow are added dropwise under stirring. Once the addition of all the amount of the acid chloride is completed, the material is maintained under stirring during one hour and is then allowed to stand during 24 hours in a refrigerator and finally 24 hours at room temperature. The temperature is then raised to 30-40°C to dissolve the precipitate which occurred. The mixture is then cooled and poured in ice-water containing hydrogen chloride (1:1). Stand 24 hours, filter and wash several times with water and once with cold alcohol. Following two recrystallisazions from alcohol, there are obtained 380 g of perfect prismatic crystals melting at 90-91°C. Esterification yield: 80%.

Therapeutic Function

Antiinflammatory, Analgesic