One-pot synthesis of (1 RS,21 SR)-diethyl 2-[23-amino-22-ethoxycarbonyl-8,11,14-trioxa-25-azatetracyclo[19.3.1.0 2,7.0 15,20]pentacosa-2,4,6,15(20),16,18,22-heptaen-25-yl]but-2-endioate

The title compound, C30 H34 N2 O9 (4), is a product of the Michael reaction of azacrown ether with dimethyl acetylenedicarboxylate modified by an addition of NH 3 (aq.) at 298 K. The aza-14-crown-4-ether ring adopts a bowl conformation. The dihedral angle between the planes of the benzene rings fused to the aza-14-crown-4-ether moiety is 8.65 (5)°. The tetrahydropyridine ring has a boat conformation. The molecular conformation is supported by one N-H..O and two C-H..O intramolecular hydrogen bonds. Both heterocyclic and amino N atoms have essentially planar configurations (sums of the bond angles are 359.35 and 358.00°). Compound 4 crystallizes as a racemate consisting of enantiomeric pairs of the 1R,21S diastereomer. In the crystal, molecules of 4 are connected by N-H..O hydrogen bonds, forming chains along [100]. According to the PASS program (computer prediction of biological activities), compound 4 may exhibit antiallergic (72% probability) and antiasthmatic (67%) activity, as well as be a membrane permeability inhibitor (65%). © 2018 Tran et al.