The Crystal Structure of 1-Ethyl-5-bromouracil. I. The Crystal Structure of the Form I Crystal of 1-Ethyl-5-bromouracil

Abstract

Abstract 1-Ethyl-5-bromouracil, C6H7N2O2Br, is crystallized in two forms. Crystals of the form I are monoclinic with four molecules in a unit cell of dimensions; a=7.89, b=12.01, c=9.71 Å, β=121.0°, space group P21⁄c, Three-dimensional intensity data were collected by diffractometer with Mo-Kα radiation. The structure was determined by heavy atom method and refined by the block-diagonal least-squares method. The final R-value was 0.052 for all observed reflections. The molecules are joined together in pairs around a center of symmetry with two N–H···O hydrogen bonds connecting N(3) to carbonyl oxygen O(4), and stacked with the base plane tilted each other.