反应详情

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.

1. additionanother 7 ml portion of base is added to the reaction mixture
2. stirringAfter shaking for 15 minutes the procedure
3. extractionextracted several times with ether
4. customAfter the ethereal layer is separated the aqueous phase
5. customis salted with 20 g of sodium acetate trihydrate at 55° C
6. stirringwith stirring
7. filtrationThe reaction mixture is filtered
8. waitafter standing overnight at room temperature
9. washwashed with absolute ethanol and ether