176445-79-7Relevant articles and documents
Serotoninergic properties of new conformationally restricted benzamides
Yang,Bremont,Shen,Kefi,Langlois
, p. 231 - 239 (2007/10/03)
A new series of benzamides derived from metoclopramide have been synthesized, in which the vicinal carbon of the basic nitrogen atom of the ethyl chain is situated on the C3, C4, C5 and C6 rings. The diamino derivatives were prepared through Strecker's reaction from the corresponding ketones except for the cyclopropyl derivatives where 1-ethoxy-1-trimethylsiloxy cyclopropane was used as the starting material. The benzamides were prepared using the mixed anhydride method. They were tested in binding assays for D2, 5-HT3 and 5-HT4 receptors. The results show a marked increase in the selectivity and potency of these derivatives for 5-HT3 receptors with regard to metoclopramide (compound 1d: 5-HT3 K(i) = 9.03 nM; 5-HT4 K(i) > 5000; D2 K(i) > 5000). The influences of steric hindrance and hydrophobic properties on the affinity of benzamide derivatives for 5-HT3 receptors were also emphasized by these data. The X-ray crystal structure of compound 1d was compared with that of the minimal energy conformer of BRL 24682, a reference 5-HT3 receptor antagonist benzamide, determined using the Random Search program. Superimposition of the two structures showed a suitable fit between the pharmacophore groups previously determined to be important for 5-HT3 receptor antagonists. On the other hand, the hydrophobic parts of the basic moieties had different spatial occupancies.