The structure of N-(5-aminopyrimidin-2-yl)-N-methyl-2-methoxymethylaniline in solid state (X-ray crystallography) and in solution (NMR) and determination of its protonation site

The structure of the title compound was determined both in the solid state by crystallography and in solution by NMR, particularly concerning the conformation around the C2–N8 bond. Hirshfeld surface (HS) analysis of this molecule was performed, using Crystal Explorer 25.09, in order to evaluate the...

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Detalles Bibliográficos
Autores: Reviriego, Felipe, Delgado Martínez, Patricia, Torralba, María del Carmen, Claramunt, Rosa M., Alkorta, Ibon, Elguero, José
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universidad Nacional de Educación a Distancia
Repositorio:e-spacio. Repositorio Institucional de la UNED
Idioma:inglés
OAI Identifier:oai:e-spacio.uned.es:20.500.14468/30356
Acceso en línea:https://hdl.handle.net/20.500.14468/30356
Access Level:acceso abierto
Palabra clave:2306 Química orgánica
2302 Bioquímica
5-aminopyrimidines
X-ray crystallography
B3LYP/6-311++G(d,p) calculations
Protonation site
Descripción
Sumario:The structure of the title compound was determined both in the solid state by crystallography and in solution by NMR, particularly concerning the conformation around the C2–N8 bond. Hirshfeld surface (HS) analysis of this molecule was performed, using Crystal Explorer 25.09, in order to evaluate the zones of potential intermolecular contacts in the crystal as well as to determine the atoms involved. As crystals of the protonated form could not be obtained due to the rapid decomposition of the pyrimidine ring, multinuclear 1H, 13C, and 15N NMR spectroscopy was employed. This revealed that protonation occurs on the ring nitrogens in a 90/10 ratio. Theoretical calculations of geometries and energies have been carried out at the Becke Three-parameter Lee–Yang–Parr (B3LYP)/6–311++G(d,p) level, and the optimized structures used to calculate chemical shifts via the Gauge-Invariant Atomic Orbital (GIAO) method. These calculations were crucial to draw definitive conclusions.