Synthesis of 6,21-dioxo-5,22-diaza[10.10]paracyclophane and its structural characteristics

Abstract

A novel paracyclophane, 6,21-dioxo-5,22-diaza[10.10]paracyclophane (4) has been synthesized by a condensation of 5,5′-p-phenylenebis (valeroyl chloride)(5) with 4,4′-p-phenylenebis(butylamine)(3) by a high dilution method. It has been characterized by means of u.v., i.r., and n.m.r. spectroscopy. The two amide bonds in compound (4) were found to assume the s-trans-geometry. No significant transannular interaction was observed between the two benzene rings. Upon cooling, the rotation of the benzene rings was hindered as evidenced by splitting of the n.m.r. ring proton signal into a doublet. The energy of activation for this hindered rotation was evaluated as 0.9 kcal/mol with a coalescence temperature of 30 ± 5 °C.