A new class of substituted 1-phenyl-3-piperazinyl-2-propanones with antimuscarinic activity is reported. As part of a structure-activity relationship study of this class, various structural modifications, particularly ones involving substitution of position 1 and the terminal piperazine nitrogen, were investigated. The objective of this study was to derive new antimuscarinic agents with potential utility in treating urinary incontinence associated with bladder muscle instability. These compounds were examined for M1, M2, and M3 muscarinic receptor selectivity in isolated tissue assays and for in vivo effects on urinary bladder contraction, mydriasis, and salivation in guinea pigs. Potency and selectivity in these assays were influenced most notably by the nature of the substituent group on the terminal nitrogen of the piperazine moiety. Benzyl substitution was particularly advantageous in producing compounds with functional M3 receptor (smooth muscle) and bladder selectivity; it provided several candidates for clinical study. In vivo, 3-(4-benzyl-piperazinyl)-1-cyclobutyl-1-hydroxy-1-phenyl-2-propanone (24) demonstrated 11- and 37-fold separations in its effect on bladder function versus mydriatic and salivation responses, respectively. The corresponding 2-chlorobenzyl derivative 25 was more than 178-fold selective for M3 versus M1 and M2 muscarinic receptors. 3-(4-Benzylpiperazinyl)-1,1-diphenyl-1-hydroxy-2-propanone (51) was 18-fold selective for M3 versus M1 and 242-fold selective for M3 versus M2 receptors. It was also selective in guinea pigs, where it displayed 20- and 41-fold separations between bladder function and effect on mydriasis and salivation, respectively. In general, the results of this study are consistent with the proposition that the described piperazinylpropanones interact with muscarcinic receptors in a hydrogen-bonded form that presents a conformation similar to that apparently adopted by classical antimuscarinic agents.

中文翻译：

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一些1-环烷基-1-羟基-1-苯基-3-（4-取代的哌嗪基）-2-丙烷和相关化合物的合成及其抗毒蕈碱活性。

报道了一种具有抗毒蕈碱活性的新型取代的1-苯基-3-哌嗪基-2-丙烷。作为此类结构-活性关系研究的一部分，研究了各种结构修饰，特别是涉及取代位置1和末端哌嗪氮的修饰。这项研究的目的是获得新的抗毒蕈碱药物，在治疗与膀胱肌肉不稳相关的尿失禁方面具有潜在的实用性。在分离的组织测定中检查了这些化合物的M1，M2和M3毒蕈碱受体选择性，以及在豚鼠体内对膀胱收缩，瞳孔散大和唾液分泌的体内影响。在这些测定中的效力和选择性最显着地受到哌嗪部分末端氮上取代基基团的性质的影响。苄基取代在生产具有功能性M3受体（平滑肌）和膀胱选择性的化合物方面尤为有利。它为临床研究提供了一些候选人。在体内，3-（4-苄基哌嗪基）-1-环丁基-1-羟基-1-苯基-2-丙酮（24）在对膀胱功能，散瞳和唾液反应的影响中表现出11倍和37倍的分离， 分别。相对于M1和M2毒蕈碱受体，相应的2-氯苄基衍生物25对M3的选择性高178倍以上。3-（4-苄基哌嗪基）-1,1-二苯基-1-羟基-2-丙酮（51）对M3的选择性是M3的18倍，对M3受体的选择性是242倍。它在豚鼠中也具有选择性，在膀胱功能与散瞳和流涎作用之间分别显示出20倍和41倍的分离。