Hydrochloric Acid → HCID 23312049, compound

Participants

Reaction Steps

A suspension of 72.8 g (526 mmol) of freshly calcined potassium carbonate in 300 ml of 1,2-dimethoxyethane is stirred under nitrogen for 10 minutes using a high-speed stirrer and then, while stirring normally, 37.0 g (105.3 mmol) of 4-(3-acetamido-4-methoxyphenylsulphonyl)-5-methyl-1,2-benzenediol, 16.5 g (105.3 mmol) of dichloroacetic acid ethyl ester and 3 g of tetrabutylammonium bromide are added. The mixture is boiled under reflux, 300 ml of acetone are added, the whole is boiled under reflux for 3 more hours, a further 60 g of potassium carbonate and 16.5 g of dichloroacetic acid ethyl ester are added, and the whole is boiled under reflux for 9 more hours. The reaction mixture is poured into water and acidified to pH 1-2 with hydrochloric acid. Some of the solvent is evaporated off in vacuo and the aqueous phase remaining is extracted with ethyl acetate. The combined organic phases are washed with water and saturated sodium chloride solution, dried over sodium sulphate and concentrated by evaporation in a rotary evaporator. The residue is recrystallised four times from acetonitrile, yielding 5-(3-acetamido-4-methoxyphenylsulphonyl)-6-methyl-1,3-benzodioxole-2-carboxylic acid in the form of white crystals having a melting point of 230° (sintering at 150°).

Provenance & Evidence