Acta Crystallographica, Section C: Crystal Structure Communications 2007-11-01

An unusual syn conformation of 5-formyluracil stabilized by supramolecular interactions.

Gustavo Portalone, Marcello Colapietro

文献索引：Acta Crystallogr. C 63(Pt 11) , o650-4, (2007)

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摘要

The asymmetric unit of the amino-oxo tautomer of 5-formyluracil (systematic name: 2,4-dioxo-1,2,3,4-tetrahydropyrimidine-5-carbaldehyde), C(5)H(4)N(2)O(3), comprises one planar amino-oxo tautomer, as every atom in the structure lies on a crystallographic mirror plane. At variance with all the previously reported small-molecule crystal structures containing the 5-formyluracil residue, the formyl substituent in the title compound exhibits an unusual syn conformation. The molecules are linked into planar sheets parallel to the bc plane by a combination of six N-H...O and C-H...O hydrogen bonds. Four of the hydrogen bonds are utilized to stabilize the formyl group in the syn conformation.