Hydrochloric Acid → HCID 19780703, compound

Participants

Reaction Conditions

Reaction Steps

2,3-Dimethyl-4-oxo-4H-chromene-6-sulphonyl chloride (obtained as described in J. Org. Chem., 1956, page 1104) (3.05 g, 11.2 mM) was added in small portions to a vigorously stirred solution of sodium hydrogen carbonate (1.88 g, 22.4 mM) and anhydrous sodium sulphite (2.54 g, 20.2 mM) in water (14 ml) at 75° C. When the addition was complete, the mixture was vigorously stirred at 75° C. for 45 minutes. The clear solution was allowed to cool to ambient temperature, diluted to 20 ml with water, and acidified with 2M hydrochloric acid at 0° C. The precipitated solid was collected by filtration, washed with a minimum of cold water, and air dried to give 2,3-dimethyl-4-oxo-4H-chromene-6-sulphinic acid as a white solid (2.16 g). This acid was converted to its sodium salt by addition of a methanolic solution of sodium methoxide [prepared from sodium (0.12 g) and methanol (100 ml)], and evaporation of the solution. The resultant sodium salt, obtained as a cream solid, was used immediately without further purification.

Provenance & Evidence