Sulfuric Acid → SC-48274

Participants

Reaction Conditions

Reaction Steps

A reaction vessel is charged with 11.24 kg of diethyl 2-[2-cyano-5-(dimethylamino)-2-(3-methoxyphenyl)-1,1-dimethylpentyl]propanedioate, monohydrochloride (9), and a solution of 11.46 kg of sulfuric acid (96% w/w) in 90L of water is added. The reaction mixture is refluxed for about 54 h. When the reaction is complete as indicated by thin layer chromatography, the solution is cooled to 25° C. The aqueous solution is washed with 20L of methylene chloride. The aqueous phase is mixed with 40L of methylene chloride and basified with 19L of aqueous ammonium hydroxide (29% w/w) while maintaining the temperature at less than 30° C. After separation of the layers, the aqueous phase is extracted twice with 20-L portions of methylene chloride. The combined organic phase is washed twice with 20-L portions of water and filtered through a layer of diatomaceous earth.

Provenance & Evidence