OH N-[4-([(2, 4-Diamino-6-pteridyl)-methyl]-amino)-IX IV benzoyl]-glutamic Acid (I)(“Aminopterin”).-A mixture of 27.4 g. of 2, 4, 5, 6-tetraminopyrimidine sulfate dihydrate,” 24.4 g. of barium chloride dihydrate and 500 ml. of woater was heated at 60” for ten minutes, then cooled to 45. 9-Aminobenzoyl-l (+)-glutamic acid (13, 3 9.) was added, and the PH was adjusted to 3 with 5 N sodlum hydroxidesolution. During twentyminutes21. 7 g. of 2, 3- ...