Benzenesulfonyl chloride → 2-Hydroxy-3-ethoxybenzaldehyde benzenesulphonate

Participants

Reaction Conditions

Reaction Steps

3-Ethoxysalicylaldehyde (498 g, 3 moles) and sodium hydroxide (140 g, 3.5 moles) in 1.5 liters of water are introduced into a 4 liter reactor provided with mechanical stirring, a condenser and a nitrogen inlet. The mixture is taken to 60° C. and benzenesulphonyl chloride is added dropwise over three-quarters of an hour. The mixture is heated to 75° C. for a quarter of an hour. It is cooled. An oil forms which crystallizes with time. It is filtered, washed with water and dried. The 2-hydroxy-3-ethoxybenzaldehyde benzenesulphonate (901 g, yield=98%) is used for the following stage. It can be recrystallized from 90:10 acetic acid/water. A white powder is obtained, m.p.=68°-69° C.

Provenance & Evidence