Troponoid. V. Crystallographic studies on AY-27110 — a dopamine agonist of the troponylpiperazine series

Abstract

The crystal structure and absolute configuration of a p-bromobenzoyl derivative, 2, of the (−)2-[4-[2-hydroxy-2-(3′,4′-dimethyl-phenyl)ethyl]-1-piperazinyl]-2,4,6-cycloheptatrien-1-one, 3a (AY-27110), which is a dopamine agonist, have been determined by an X-ray analysis. Crystals of C28H29BrN2O5, fw = 553.47, are monoclinic P21, a = 12.553(2), b = 6.359(1), c = 17.575(3) Å, β = 108.32(1)°, V = 1331.81 Å3, Z = 2, ρc = 1.380, ρo = 1.384 g cm−3. For 2155 observed reflexions, the final R is 0.036 and R(w) is 0.039. The chirality of this enantiomer is shown to be S(−), based on 18 reflexions with significant differences in the intensities of the corresponding Friedel pairs. The piperazine ring has a distorted chair form that is flattened at the N atom nearest the cycloheptatriene ring as for the psychoactive agents loxapine and amoxapine.