One-Pot Synthesis and Transmembrane Chloride Transport Properties of C3-Symmetric Benzoxazine Urea

Abstract

One-pot synthesis of a C3-symmetric benzoxazine-based tris-urea compound is discussed. 1H NMR titrations indicate a stronger Cl– binding compared that of Br– and I– by the receptor. Effective Cl– transport across liposomal membranes via a Cl–/X– antiport mechanism is confirmed. Theoretical calculation suggests that a few water molecules with N–H, C═O, and the aromatic ring of the receptor create a H-bonded polar cavity where a Cl– is recognized by O–H···Cl– interactions from five bridged water molecules.