Acetic Anhydride → 2-Chloro-6-cyano-4-(3-fluorosulfonylphenylazo)phenyl acetate

Participants

Reaction Conditions

Reaction Steps

3-Chloro-5-(3-fluorosulfonylphenylazo)-2-hydroxybenzaldehyde oxime (22.5 g, 0.063 mol) was added to 150 ml acetic anhydride and heated to 95° C. Sodium acetate (3.0 g) was added. After 21/2 hours, the reaction mixture was poured into 750 ml water and stirred at room temperature until anhydride fully hydrolysed. The resulting precipitate was filtered off. The solids which became gummy on standing were dissolved in 75 ml chloroform and poured onto a silica gel column. Elution with 10% hexane in chloroform gave the desired dye as the first component. Removal of the solvents under reduced pressure gave an oil which hardened on standing but did not crystallize. Yield: 16.8 g (70%).

Provenance & Evidence