3-(2-Chloro-5-methylphenoxy)propane-1,2-diol

Abstract

3-(2-Chloro-5-methylphenoxy)propane-1,2-diol 1 is a possible precursor in the chiral beta blocker Bupranolol synthesis. Both racemic and single-enantiomeric samples of 1 were synthesized and characterized by single crystal XRD. The absolute configuration of an (S)-1 sample was determined by data refinement (the value of the Flack parameter is 0.03(4)). Hydrogen-bonded supramolecular synthons (SMS) were identified for both crystals. In rac-1, as well as in (S)-1 crystals, one of the two main SMS is the homochiral chain C11(5):21 (⋯O1–C1–C2–O2–H2⋯). The second of the two SMSs changes is the change of chiral environment. For rac-1, this is the heterochiral chain C33(9):{12/12/21}; (⋯O2–C2–C1–O1–H1⋯O′2–H′2⋯O″1–H″1⋯), in which molecules with different configurations alternate. In (S)-1 crystals, this is the homochiral chain C11(2):11 (⋯O1–H1⋯). The results obtained once again confirm the influence of the chiral environment on the crystallization of scalarly identical molecules.