199292-65-4

Upstream product

• 22876-19-3 5-chloro-2-mercaptobenzoxazole 
• 109-01-3 1-methyl-piperazine 

Relevant academic research and scientific papers

Regulatory molecules for the 5-HT3 receptor ion channel gating system

Substituted benzoxazole derivatives which possess a nitrogen-containing heterocycle at C2 are selective partial agonists of the 5-HT3 receptor. Alteration of substituents on the benzoxazole nucleus affords both agonist-like and antagonist-like compounds, and uniquely modifies the function of the 5-HT3 receptor ion channel gating system. SAR and corroborative computational docking study for these partial agonists successfully explained structure and function of the 5-HT3 receptor.

Serotonin 5-HT3 receptor partial activator

This invention provides a serotonin 5-HT3 receptor partial activator which has a serotonin 5-HT3 receptor activating action, in addition to its serotonin 5-HT3 receptor antagonism, and does not cause constipation as a side effect. Particularly, based on the finding that newly synthesized benzoxazole derivatives typified by the compounds of the following formula (2) have strong serotonin 5-HT3 receptor antagonism and serotonin 5-HT3 receptor activating action, this invention provides these benzoxazole derivatives as serotonin 5-HT3 receptor partial activators. In the above formula, R1 to R4 may be the same or different from one another and each represents a hydrogen atom, a halogen atom, a substituted or unsubstituted lower alkyl group, a substituted or unsubstituted lower alkenyl group or a substituted or unsubstituted amino group, or two groups of R1 and R2 may be linked together to form a ring structure, namely benzene ring; R5 represents a hydrogen atom, a substituted or unsubstituted lower alkyl group or a substituted or unsubstituted lower alkenyl group; and m is an integer of 1 to 4.

Benzoxazole derivatives as novel 5-HT3 receptor partial agonists in the gut

A series of benzoxazoles with a nitrogen-containing heterocyclic substituent at the 2-position was prepared and evaluated for 5-HT3 partial agonist activity on isolated guinea pig ileum. The nature of the substituent at the 5-position of the benzoxazole ring affected the potency for the 5-HTs receptor, and the 5-chloro derivatives showed increased potency and lowered intrinsic activity. 5-Chloro-7-methyl-2-(4-methyl-1- homopiperazinyl)benzoxazole (6v) exhibited a high binding affinity in the same range as that of the 5-HT3 antagonist granisetron, and its intrinsic activity was 12% of that of 5-HT. Compound 6v inhibited 5-HT-evoked diarrhea but did not prolong the transition time of glass beads in the normal distal colon even at a dose of 100 times the ED50 for diarrhea inhibition in mice. Compounds of this type are expected to be effective for the treatment of irritable bowel syndrome without the side effect of constipation.

A new 5-HT3 receptor ligand. II. Structure-activity analysis of 5-HT3 receptor agonist action in the gut

Several modified 2-piperazinyl benzoxazole derivatives, which exhibit an agonistic effect on gastrointestinal motility, were synthesized and their effects on the contraction of guinea-pig ileum were examined. The quaternary piperazinyl benzoxazole structure has a restricted conformation and stereostructure compared to those of the other 5-HT3 receptor agonists, serotonin and meta-chlorophenylbiguanide. The mutual positions of the aromatic ring, nitrogen atom and terminal amine are considered to form the pharmacophore of the 5-HT3 receptor agonist in the gut. In the serotonin- evoked reflex bradycardia [Bezold-Jarisch (B-J) reflex] inhibition test using rats the B-J reflex-inducing ratio was different for each synthesized compound. These results suggest that, in these 5-HT3 receptor agonists, the substituents of the benzoxazole ring influence the B-J reflex-inducing activity in rats.