62910-60-5Relevant academic research and scientific papers
Synthesis and structure-activity relationships of 2,3-dihydrobenzofuran- 7-carboxamide derivatives as potent serotonin-3 (5-HT3) receptor antagonists
Kuroita,Yasumoto,Inaba,Sakamori,Takehara,Kawakita
, p. 95 - 100 (1994)
A series of N-(azabicyclo-3-yl)-2,3-dihydrobenzofuran-7-carboxamide derivatives were synthesized and evaluated for serotonin-3 (5-HT3) receptor antagonistic activities assessed by 5-HT3 receptor binding (in vitro) and by the ability to antagonize the von Bezold-Jarisch reflex in rats (in vivo). In these compounds, 1-azabicyclo[2.2.2]oct-3-yl derivatives were more potent than 8-methyl-8-azabicyclo[3.2.1]oct-3-yl derivatives for 5-HT3 receptor antagonistic activities. The introduction of methyl groups at position 2 of the dihydrobenzofuran ring increased the pharmacological activities (dimethyl > monomethyl > dihydro). Furthermore, the stereoisomers of dimethyl-, monomethyl-, and dihydrobenzofuran derivatives were prepared to evaluate the stereoselectivity of their 5-HT3 receptor binding affinities. Concerning the basic part, the compounds bearing (S)-1-azabicyclo[2.2.2]octan-3-yl moiety were more potent than their counterparts. With respect to the methyl substituent at position 2 of the dihydrobenzofuran ring, the rank order of the potency was dimethyl ≥ (2S)-methyl > (2R)-methyl > dihydro. These results suggest that the (2S)-methyl group of the dihydrobenzofuran part contributes to the enhancement of the pharmacological activity. Among these compounds, (S)-N-(1-azabicyclo[2.2.2]oct-3-yl)-5-chloro-2,3-dihydro-2,2- dimethylbenzofuran-7-carboxamide hydrochloride (24) showed the highest affinity for 5-HT3 receptors (K(i) = 0.055 nM), and the most potent antagonistic activity on the von Bezold-Jarisch reflex (ED50 = 0.18 μg/kg i.v.).
Zatosetron, a Potent, Selective, and Long-Acting 5HT3 Receptor Antagonist: Synthesis and Structure-Activity Relationships
Robertson, David W.,Lacefield, William B.,Bloomquist, William,Pfeifer, William,Simon, Richard L.,Cohen, Marlene L.
, p. 310 - 319 (2007/10/02)
Antagonists of 5HT3 receptors are clinically effective in treating nausea and emesis associated with certain oncolytic drugs, including cisplatin.Moreover, these agents may be useful in pharmacological management of several central nervous system disorders, including anxiety, schizophrenia, dementia, and substance abuse.Our studies on aroyltropanamides led to the discovery that dihydrobenzofuranyl esters and amides are potent 5HT3 receptor antagonists.Simple benzoyl derivatives of tropine and 3α-aminotropane possessed weak 5HT3 receptor antagonist activity, as judged by blockade of bradycardia produced by iv injection of serotonin (5HT) to anesthetized rats.Within this series, use of benzofuran-7-carboxamide as the aroyl moiety led to a substantial increase of 5HT3 receptor affinity.The optimal 5HT3 receptor antagonist identified via extensive SAR studies was endo-5-chloro-2,3-dihydro-2,2-dimethyl-N-(8-methyl-8-azabicyclooct-3-yl)-7-benzofurancarboxamide (Z)-2-butenedioate (zatosetron maleate).The 7-carbamyl regiochemistry, dimethyl substitution, chloro substituent, and endo stereochemistry were all crucial elements of the SAR.Zatosetron maleate was a potent antagonist of 5HT-induced bradycardia in rats (ED50=0.86 μg/kg iv).Low oral doses of zatosetron (30 μg/kg) produced long-lasting antagonism of 5HT3 receptors, as evidenced by blockade of 5HT-induced bradycardia for longer than 6 h in rats.Moreover, this compound did not produce hemodynamic effects after iv administration to rats, nor did it block carbamylcholine-induced bradycardia in doses that markedly blocked 5HT3 receptors.Thus, zatosetron is a potent, selective, orally effective 5HT3 receptor antagonist with a long duration of action in rats.
