Sulfuric Acid → HCID 22991730, compound

Participants

Reaction Steps

A three-neck, 5 liter round bottom flask contained 328.0 g. of N-ethyl-N-(2-hydroxyethyl)-2-methyl-p-phenylenediamine (assay 98.0%, 1.655 moles), and was equipped with an overhead agitator, an addition funnel, and a reflux condenser. The flask was carefully purged with nitrogen to remove any residual oxygen. The flask was charged with 2,150 g of anhydrous ethyl alcohol and 32 g of water. The solution was agitated at room temperature for ten minutes. The addition funnel was charged with 96% sulfuric acid (185.4 g., 1.815 moles). The sulfuric acid was added to the free base solution over a period of 30 minutes, allowing the temperature to rise to about 45-50° C. The solution was then heated to 75° C., and held at this temperature for 30 minutes. The solution was thereafter cooled to 10° C. over a two hour period. The acid salt product, N-ethyl-N-(2-hydroxyethyl)-2-methyl-p-phenylenediamine sulfate, was formed as a white precipitate. The solids were isolated by filtration, then washed with ethyl alcohol having a temperature of about 0-20° C. The solids were dried at 60° C. and under 10 mm psia for 16 hours. The dried N-ethyl-N-(2-hydroxyethyl)-2-methyl-p-phenylenediamine sulfate, a white crystalline material, weighed 455.0 g. (1.556 moles, 94.0% yield from free base). The data for the isolation of CD-4 acid salt in three separate experiments from distilled, purified, N-ethyl-N-(2-hydroxyethyl)-2-methyl-p-phenylenediamine by the process described above are shown in Table V below.

Provenance & Evidence