Cocrystallization of Chiral N7,N16-bis (S-1-Phenylethyl)-1,4,10,13-Tetraoxo-7,16-Diazacyclooctadecane-7,16-Dicarboxamide with Hydrochlorides of Methyl Ethers of Leucine and Valine Enantiomers

An attempt to co-crystallize N7,N16-bis(S-1-phenylethyl)-1,4,10,13-tetraoxo-7,16-diazacyclooctadecane-7,16-dicarboxamide (1) with hydrochlorides of methyl ethers (HCMEs) of L- and D-valine and also L- and D-leucine results in separate crystallization of diazacrown-ether 1 (or its monohydrate 1·H₂O) and HCMEs of respective α-amino acids. Crystal structures of D-leucine 1·H₂O (1) and HCME (2) compounds, which were not described previously, are solved by single crystal X-ray diffraction.