The general procedure for the synthesis of sodium (R)-3-(2,4-dihydroxy-3,3-dimethylbutanamido)propionate from sodium 3-aminopropionate and dihydro-3-hydroxy-4,4-dimethyl-2(3H)-furanone was as follows: 55.5 g of sodium 3-aminopropionate and 65 g of dihydro-3-hydroxy-4,4-dimethyl-2(3H)-furanone were dissolved in 350 ml of anhydrous ethanol and heated to reflux for 3 hours. After completion of the reaction, the reaction mixture was filtered while hot and the reaction vessel was washed with 50 ml of ethanol. The washed solution was combined with the filtrate and the combined filtrate was allowed to stand at 0 °C for 5 days. Subsequently, it was filtered and the resulting solid was washed with a small amount of ethanol. Finally, the solid was dried to constant weight under reduced pressure at room temperature to obtain 76.3 g of white crystalline powder, namely sodium (R)-3-(2,4-dihydroxy-3,3-dimethylbutanamido)propionate (sodium D-pantothenate), whose crystal structure is as described in GB565976.
