Synthesis and pharmacological evaluation of carboxamide derivatives as selective serotoninergic 5-HT(4) receptor agonists

Discovery and SAR of N-(1-((substituted piperidin-4-yl)methyl)-3-methoxypiperidin-4-yl)-2-methoxybenzamide derivatives: 5-Hydroxytryptamine receptor 4 agonist as a potent prokinetic agent

A series of novel benzamide derivatives, altering the 4-fluorophenylalkyl moiety in cisapride, were synthesized as 5-HT4 receptor agonists, and SAR of these analogs was examined on in vitro and in vivo prokinetic activities. These compounds were synthesized for high 5-HT4 receptor binding affinities and low hERG affinities. Several types of analogs were obtained and screened for 5-HT4 binding, hERG blocking, agonism, and gastric emptying assessment. Among the analogues, compound 23g showed promising results compared with the other analogs with respect to gastric emptying rates in rats. Therefore, we suggest that it may be a clinical candidate for the development of a potent prokinetic agent to treat GI disorders.

Synthesis and pharmacological evaluation of benzamide derivatives as selective 5-HT4 receptor agonists

It is thought that selective 5-HT(4) receptor agonists-such as 4-amino-5-chloro-2-methoxy-N-[1-(6-oxo-6-phenylhexyl)piperidin-4ylmethyl]benzamide (2)-have the ability to enhance both upper and lower gastrointestinal motility without any significant adverse effects. Modification of 2 was performed. Variation of the piperidin-4ylmethyl moiety of 2 led to a decrease in the binding affinity for the 5-HT(4) receptor. Following conversion of the carbonyl group on the benzoyl part to a hydroxyl or sulfoxide group, the binding affinity for the 5-HT(4) receptor was retained although the effect on defecation was reduced. Many of the 4-amino-5-chloro-2-methoxy-N-(piperidin-4ylmethyl)benzamides that had a ether or sulfide moiety in the side-chain part at the 1-position of the piperidine exhibited high affinity for the 5-HT(4) receptor. Among these, phenylthio 41c and benzylthio derivative 44 were selective 5-HT(4) receptor agonists, and had a similar effect on defecation to compound 2.

Synthesis and pharmacological properties of benzamide derivatives as selective serotonin 4 receptor agonists

A series of 4-amino-5-chloro-2-methoxy-N-(piperidin-4-ylmethyl)benzamides with a polar substituent group at the 1-position of the piperidine ring was synthesized and evaluated for its effect on gastrointestinal motility. The benzoyl, phenylsulfonyl, and benzylsulfonyl derivatives accelerated gastric emptying and increased the frequency of defecation. One of them, 4-amino-N-[1-[3-(benzylsulfonyl)propyl]piperidin-4-ylmethyl]-5-chloro-2-methoxybenzamide (13a, Y-36912), was a selective 5-HT4 receptor agonist offering potential as a novel prokinetic with reduced side effects derived from 5-HT3- and dopamine D2 receptor-binding affinity. In the oral route of administration, this compound enhanced gastric emptying and defecation in mice, and has a possibility as a prokinetic agent, which is effective on both the upper and the lower gastrointestinal tract.

Synthesis and biological evaluation of new 2-(4,5-dihydro-1H-imidazol-2-yl)-3,4-dihydro-2H-1,4-benzoxazine derivatives

2-(4,5-Dihydro-1H-imidazol-2-yl)-3,4-dihydro-2H-1,4-benzoxazine derivatives and tricyclic analogues with a fused additional ring on the nitrogen atom of the benzoxazine moiety have been prepared and evaluated for their cardiovascular effects as potential antihypertensive agents. The imidazoline ring was generated by reaction of the corresponding ethyl ester with ethylenediamine. Affinities for imidazoline binding sites (IBS) I(1) and I(2) and alpha(1) and alpha(2) adrenergic receptors were evaluated as well as the effects on mean arterial blood pressure (MAP) and heart rate (HR) of spontaneously hypertensive rats. With few exceptions the most active compounds on MAP were those with high affinities for IBS and alpha(2) receptor. Among these, compound 4h was the most interesting and is now, together with its enantiomers, under complementary pharmacological evaluation.