4-(4-NITROPHENYLAZO)CATECHOL synthesis

Yield: 95%

Reaction Conditions:

Stage #1:4-nitro-aniline with carboxyl- and nitrite- functionalized graphene quantum dots at 20; for 0.0833333 h;
Stage #2:benzene-1,2-diol in water at 20; for 0.166667 h;

Steps:

1 2.3 General procedure for the synthesis of azo dyes 6a-q
General procedure: The mixture of aniline derivative (30mmol) and CNGQDs (0.3gr) was thoroughly ground at room temperature for 15min. The diazonium salt product was assayed by well-known azo-coupling reaction with either a phenol or an aniline derivative. For the coupling reaction with phenolic compounds or anilines, the mixture was continuously added to the phenol or aniline (30mmol) which had been moistened with water moistened with water (0.5mL). Then water (30mL) was added to the mixture and stirred to dissolve the GQDs. After that the participated dyes were filtered and washed three times with cold water to afford the crude azo-dyes which were purified by re-crystallization from EtOH/water. Saturated solution of sodium chloride was added to the filtrate containing GQDs while stirring, then the GQDs was extracted with ethyl acetate 3×15mL and evaporation of ethyl acetate led to the GQDs.

References:

Valizadeh, Hassan;Shomali, Ashkan;Nourshargh, Saideh;Mohammad-Rezaei, Rahim [Dyes and Pigments,2015,vol. 113,p. 522 - 528]