Hydrochloric Acid → 1,2,3-Triazine

Participants

Reaction Steps

The first part of the synthesis is to obtain monochloro-monothioglycolato triazine. An aqueous dye solution (0.1 mol/100 ml, pH 7.5) of a purified Procion (RTM) dichlorotriazine dye is prepared. To this solution, a 0.1 mol solution of Mercaptoacetic acid is added by slow dripping at a temperature of between 0 and 5° C. After the addition of mercaptoacetic acid, the pH of the system is adjusted to 8 using sodium carbonate and HCl. The reaction is then allowed to proceed, at 0˜5° C. and pH8, for 5˜8 hours. For each individual dye, the required reaction time is different (7˜8 hours for Procion Red MX-8B, ˜6 hours for Procion Yellow MX-8G and ˜5 hours for Procion Blue MX-2G). During the synthesis, a rapid pH drop is observed. The end-of-reaction point, for this part of the synthesis, is indicated by the pH of the reaction system remaining constant for more than 5 minutes. At this point, the dye monochloromonothioglycolato triazine is obtained. At the end of the synthesis, the pH of the system is reduced to below pH 2. The solid monochloromonothioglycolato triazine dye compounds is then obtained following precipitation and filtration.

Provenance & Evidence