Key Factors Related To High School Girls’ Interest And Aspirations In Engineering, Science, And Math

A process for synthesizing 2-amino-5-dimethlyaminophenyl thiosulfonic acid comprises the step of oxidizing N,N'-dimethyl-rho-phenylene-diamine in the presence of a source of thiosulfate ions, while maintaining the temperature of the reaction mixture not higher than about 10° C. This compound is useful as an intermediate in the synthesis of toluidine blue O. A process for manufacturing toluidine blue O with improved yield, includes the step of preparing the intermediate 2-amino-5-diethylaminopropyl thiosulfonic acid according to the above described procedure.