Sodium Hydroxide → N-(4-Formyl-3-hydroxyphenyl)benzenesulphonamide

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Reaction Steps

432 g (1 mol) of 2,4-dioxo-hexahydro-1,3,5-trimethyl-6-[2-hydroxy-4-benzenesulphonamido-phenyl]-s-triazine (93.5% pure product) are introduced into a solution of 280 g (7 mols) of sodium hydroxide in 600 ml of water. The mixture is boiled under reflux and under nitrogen for 6 hours. A pale brown solution is formed, from which small single crystals separate out. The contents of the flask are then poured onto a mixture of 700 ml of concentrated hydrochloric acid and 2 kg of ice and the yellow product which has separated out is filtered off. After washing with water and drying at 80° C, 274 g of 4-benzene-sulphonamido-salicylaldehyde of melting point 150° to 157° C are obtained. According to the oxime titration, the aldehyde is 94.8% pure and the yield is thus 93.6%. After recrystllisation from xylene (1 : 10), the aldehyde is obtained as colourless crystals of melting point 160° to 163° C.

Provenance & Evidence