The Hydrogen Bonded Structures of Two 5-Bromobarbituric Acids and Analysis of Unequal C5-X and C5-X' Bond Lengths (X = X' = F, Cl, Br or Me) in 5,5-Disubstituted Barbituric Acids.

ABSTRACT: The crystal structure of the methanol hemisolvate of 5,5-dibromobarbituric acid (1MH) displays an H-bonded layer structure which is based on N-H⋯O=C, N-H⋯O(MeOH) and (MeOH)O-H⋯O interactions. The barbiturate molecules form an H-bonded substructure which has the fes topology. 5,5'-Methanediylbis(5-bromobarbituric acid) 2, obtained from a solution of 5,5-dibromobarbituric acid in nitromethane, displays a N-H⋯O=C bonded framework of the sxd type. The conformation of the pyridmidine ring and the lengths of the ring substituent bonds C5-X and C5-X' in crystal forms of 5,5-dibromobarbituric acid and three closely related analogues (X = X' = Br, Cl, F, Me) have been investigated. In each case, a conformation close to a C5-endo envelope is correlated with a significant

SUBMITTER: Gelbrich T 

PROVIDER: S-EPMC5493196 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature