Sodium α-Hydroxybenzenemethanesulfonic Acid
Sodium metabisulfite (627 g, 3.3 mol) was dissolved in water (1.5 L), and a small amount of insoluble substance was filtered off. The filtrate was added to a solution of benzaldehyde (500 g, 4.7 mol) in EtOH (3 L) over 3 h under ambient temperature and then the reaction mixture was stirred at 45–50 °C under an atmosphere of argon overnight. After 18 h, the reaction mixture was sampled and deemed to be complete with no benzaldehyde being detected by TLC. The heterogeneous reaction mixture was cooled to ambient temperature, stirred for 4 h, and then isolated by vacuum filtration. The product cake was washed with EtOH (two portions of 200 mL) to give the product bisulphite adduct as a white solid (907 g, 92%), after drying under vacuum at 50 °C, mp 150–152 °C, decomposition, (lit. 153–156 °C, decomposition).
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KHAJURAHO, MADHYA PRADESH, INDIA
