Several compounds derived from nicotinic acid were prepared within a more extensive programme aiming at the synthesis of new substances with expected antihistamine and antidepressant activity. Some of these compounds display certain structural resemblance with the antidepressant agent piberaline (EGYT 475, Trelibet®, I) and its analogues. The products were used as intermediates for the synthesis of further compounds and most of them were subjected to pharmacological testing. Substituted nicotinic acid piperazides IIa - IId and IVa - IVe were obtained by reactions of nicotinoyl chloride (prepared in situ) with the correspondingly substituted piperazines. Reduction of the piperazides IIa - IId and IVa - IVd with diborane in situ in tetrahydrofuran afforded corresponding 1-substituted 4-(3-pyridylmethyl)piperazines IIIa - IIId and Va - Vd. Whereas the alkylation of 1-(2-pyrimidinyl)piperazine with 2-(chloromethyl)pyridine in ethanol in the presence of triethylamine resulted in compounds Ve, compound Vf was obtained by the addition reaction of 1-(3-pyridylmethyl)piperazine to acrylamide. The piperazides VIe and VIf were prepared by reactions of 2-(3-pyridyl)acetic acid with 1-(2-pyrimidinyl)piperazine or 3-(1-piperazinyl)propionamide in N,N-dimethylformamide in the presence 1,1'-carbonyldiimidazole. A similar procedure starting from nicotinic acid afforded the piperazide IVf. Compounds Vc and Vd showed significant affinity for the histamine H1-receptors (inhibition of binding of 2 nmol/l [3H]mepyramine in membranes from the rat brain: Vc, IC50 = 28 nmol/l; Vd, IC50 = 148 nmol/l). They also proved active in test of histamine aerosol in guinea pigs (PD50 = 4.1 mg/kg p.o. for compound Vc and 2.4 for compound Vd). Results of a more detailed pharmacological testing of these compounds will be published elsewhere.
从烟酸衍生的几种化合物是在一个更广泛的项目中准备的,旨在合成具有预期抗组胺和抗抑郁活性的新物质。其中一些化合物与抗抑郁剂皮贝拉林(EGYT 475,Trelibet®,I)及其类似物具有一定的结构相似性。这些产品被用作合成更多化合物的中间体,大部分经过了药理学测试。通过烟酰氯(原位制备)与相应取代哌嗪的反应获得了取代烟酸哌嗪IIa - IId和IVa - IVe。在四氢呋喃中用二硼烷原位还原哌嗪IIa - IId和IVa - IVd得到相应的1-取代-4-(3-吡啶甲基)哌嗪IIIa - IIId和Va - Vd。在三乙胺存在下,乙醇中1-(2-嘧啶基)哌嗪与2-(氯甲基)吡啶烷基化反应得到化合物Ve,1-(3-吡啶甲基)哌嗪与丙烯酰胺加成反应得到化合物Vf。通过2-(3-吡啶)乙酸与1-(2-嘧啶基)哌嗪或3-(1-哌嗪基)丙酰胺在N,N-二甲基甲酰胺中与1,1'-碳酰二咪唑的存在下反应制备了哌嗪VIe和VIf。从烟酸出发,类似的方法得到了哌嗪IVf。化合物Vc和Vd显示出对组胺H1受体的显著亲和力(大鼠脑膜中2 nmol/l [3H]mepyramine结合抑制:Vc,IC50 = 28 nmol/l;Vd,IC50 = 148 nmol/l)。它们还在豚鼠组胺气雾试验中表现出活性(化合物Vc口服PD50 = 4.1 mg/kg,化合物Vd为2.4)。这些化合物的更详细的药理学测试结果将在其他地方发布。