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Identification of the "endothelial relaxation factor" as the endogenic NO formed from L-arginine in the vascular endothelium [1] has stimulated the search for new generation of cardiovascular drugs [2][3][4][5]. At present, it has been established that biochemical synthesis of NO proceeds by different pathways. Exogenic organic nitrates (nitroglycerin, nitrosorbid, and other classical vasodilators) are subject to reduction [6], as well as the new NO precursors such as N-nitropyrazoles [7] and furoxanes [8]. On the contrary, L-arginine -the main NO source in the organism -is oxidized by the enzyme NO-synthase (NOS) to . NOS is also capable of forming NO from [3-mercaptoethylguanidine [9,10]. Study of the weU-known vasodilator molsidomin showed that this agent generates NO by reaction with atmospheric oxygen [3]. It was found that 1,2-diazetine-l,2-dioxides form NO upon thermolysis and/or hydrolysis [I1]. Muller et al. [12] reported on the use of (+)-3-(E)-4ethyl-2[(E)-hydroxyimino]-5-nitro-3-hexenamide (FK 409) as the NO donor in solutions at pH -7.5, but failed t o establish a group (oxime, nitro, or both) acting as the source of NO [12]. Recently we have demonstrated that 3-quinuclidone oximes may serve as the source of NO and activate the soluble guanylate cyclase [13]. The purpose of this work was to extend the group of oximes and study their hypotensive activity.The NO precursors were obtained on the basis of both well-known (Va/VIa, Vb/VIb, Ve/VIe, Vi/VIi) [14], (Vc/VIc, Vd/VId, VIIb] [13], and newly synthesized (VfiVlfVh/VIh) 2-arylmethylene-3-quinuclidone oximes and their hydrogenated analogs IXb and IXe. The compact rind framework structure of quinuclidine (1-azabicyclo[2.2.2]octane) provides spatial fixation of the substituents and sufficiently high solubility of hydrochlorides, while the double bond in position 2 sometimes allows us to obtain the (Z/E) isomer

Aus den Amino‐mercaptochinoxalinen (I) werden durch Umsetzung mit α‐Halogenketonen (II) die S‐Acylalkyl‐Derivate (III) hergestellt, die in Abhängigkeit von den Substituenten in der offenen Form (III), der cyclischen Form (IV) oder in Gemischen beider Formen vorliegen.

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