acid red 54

Continuous-Flow Synthesis of Acid Red 54 in Microchannel Reactor

Yueqi Wang. Guangdong Chemical Industry, 2016, 43(7), 1-2.

Acid red 54 dye can be prepared by continuous coupling using microchannel reactor. The optimized process conditions include: the molar ratio of diazo component to coupling component is 1:1, flow rate v=0.18 m/s, residence time t=11.11s, and microchannel inner diameter D=1.0 mm. The synthesis yield of acid red at room temperature can reach 96.8%.
Synthetic procedure of acid red 54
· Weigh a certain amount of anthranilic acid, dissolve it in 36% HCl solution, and then add a certain amount of water.
· Add 30% NaNO2 solution dropwise under ice bath conditions to carry out diazotization reaction for 1 hour.
· Use urea to remove excess sodium nitrite, and use NaHCO3 to adjust the pH to prepare the diazo component.
· Add NaHCO3 to γ acid to dissolve and then dilute with water to prepare the coupling component.
· The above-mentioned diazo component and coupling component are coupled in a polytetrafluoroethylene tube at the same flow rate to prepare the target dye acid red 54.