2,4-Diamino-5-(4-chlorophenyl)-6-ethylpyrimidin-1-ium 2-acetamidobenzoate

Abstract

The title compound, C12H14ClN4 +·C9H8NO3 −, is a salt with a 1:1 ratio of cation and anion components inter­acting with each other forming an R 2 2(8) ring motif. The crystal structure is stabilized by hydrogen bonds (N—H⋯O) involving two different eight-membered rings. One of them is formed between the pyrimidine ring (donor) and the carboxylate group (acceptor) from the benzoate, whereas the other ring is formed by N—H⋯O interactions, which help to form a dimer between two symmetry-related salts in the unit cell. In addition, an intramolecular C—H⋯N and intermolecular C—H⋯Cl interactions help to control the molecules in the unit-cell packing.

Salts, Binary and Ternary Cocrystals of Pyrimethamine: Mechanosynthesis, Solution Crystallization, and Crystallization from the Gas Phase

“…Pyrimethamine (PYR, Figure ) is a folic acid antagonist and is used to treat malaria and toxoplasmosis. Various binary cocrystals and salts of PYR with carboxylic acids, − saccharin, and sulfonates , have been described. The most basic site is the N1 nitrogen (p K a = 6.94), and R 2 2 (8) rings with H bonding between the carboxylate and the N1–H + /C2–NH 2 site are a recurrent motif in PYR/carboxylic acid binary systems. − Likewise, in the methanol-solvated saccharin salt, the saccharin anion forms a pair of N – ···H + N1 and CO···H 2 N–C2 H bonds with the N1-protonated 2-aminopyrimidine site of PYR .…”

“…Various binary cocrystals and salts of PYR with carboxylic acids, − saccharin, and sulfonates , have been described. The most basic site is the N1 nitrogen (p K a = 6.94), and R 2 2 (8) rings with H bonding between the carboxylate and the N1–H + /C2–NH 2 site are a recurrent motif in PYR/carboxylic acid binary systems. − Likewise, in the methanol-solvated saccharin salt, the saccharin anion forms a pair of N – ···H + N1 and CO···H 2 N–C2 H bonds with the N1-protonated 2-aminopyrimidine site of PYR . Sulfa drugs with an N­(heterocycle)CH–NH­(sulfonamide) functionality have been shown to interact with the C2–NH 2 /N1 site of the related 2,4-diaminopyrimidine trimethoprim, either with − or without − proton transfer.…”