4-Nitrobenzoyl chloride → Disodium

Participants

Reaction Steps

A solution of 2.0 g of 6-amino-5-(4-amino-2-sulfophenylazo)-4-hydroxy-2-naphthalenesulfonic acid, disodium salt in 14.0 ml of N sodium hydroxide is treated with 2.0 g of p-nitrobenzoyl chloride and a few drops of ether. The reaction mixture is shaken for 3 to 4 minutes and then another 7 ml portion of base is added to the reaction mixture. After shaking for 15 minutes the procedure is repeated with an additional 7 ml portion of base. Finally the reaction mixture is acidified with 2 ml of glacial acetic acid, and extracted several times with ether. After the ethereal layer is separated the aqueous phase is salted with 20 g of sodium acetate trihydrate at 55° C with stirring. The reaction mixture is filtered after standing overnight at room temperature and washed with absolute ethanol and ether to give 6-amino-4-hydroxy-5-[4-(p-nitrobenzamido)-2-sulfophenylazo]-2-naphthalenesulfonic acid, disodium salt.

Provenance & Evidence