Abstract
Determination of 5-acetamidomethyl-4-amino-2-methylpyrimidine was carried out. Its basicity increases markedly in glacial acetic acid and it was titrated as 1 mole is 1 equivalent with 0.1 N perchloric acid. A mixed indicator was tried as the indicator and a mixture of methyl violet and bromophenol blue was found to show excellent change of color from reddish amber to blue at the equivalent point. Of the impurities included during the course of synthesis of this pyrimidine compound, sodium acetate and 4-amino-5-ethoxymethyl-2-methylpyrimidine quantitatively consumes perchloric acid and constitute the sources of error. The former can be removed by treatment with ion exchange resin and the latter by extraction with chlorobenzene. The determination accuracy was within ±0.2% with reference standard and within ±0.4% by separatory determination of an impure sample.
