7151-19-1Relevant articles and documents
Rhodium-catalyzed oxidative cycloaddition of benzamides and alkynes via C-H/N-H activation
Hyster, Todd K.,Rovis, Tomislav
supporting information; experimental part, p. 10565 - 10569 (2010/09/17)
The oxidative cycloaddition of benzamides and alkynes has been developed. The reaction utilizes Rh(III) catalysts in the presence of Cu(II) oxidants, and is proposed to proceed by N-H metalation of the amide followed by ortho C-H activation. The resultant rhodacycle undergoes alkyne insertion to form isoquinolones in good yield. The reaction is tolerant of extensive substitution on the amide, alkyne, and arene, including halides, silyl ethers, and unprotected aldehydes as substituents. Unsymmetrical alkynes proceed with excellent regioselectivity, and heteroaryl carboxamides are tolerated leading to intriguing scaffolds for medicinal chemistry. A series of competition experiments shed further light on the mechanism of the transformation and reasons for selectivity.
Piperazinylalkyl Heterocycles as Potential Antipsychotic Agents
Scott, Malcolm K.,Baxter, Ellen W.,Bennett, Debra J.,Boyd, Robert E.,Blum, Paul S.,et al.
, p. 4198 - 4210 (2007/10/03)
We recently reported on a series of pyrrole Mannich bases orally active in inhibiting the conditioned avoidance response (CAR) in rats.These compounds exhibit affinity for both D2 and 5-HT1A receptors, and some are noncataleptogenic.Such a profile suggest that they may be potential antipsychotic agents which lack the propensity for causing extrapyramidal side effects and tardive dyskinesias in humans.One of these compounds, 1--1-piperazinyl>methyl>-1H-pyrrol-2-yl>methyl>-2-piperidinone (RWJ 25730, 1), was chosen for further development but found to be unstable in dilute acid.In order to improve stability, we replaced the pyrrole methylene linkage to the piperazine ring with ethylene, employed ethylene and dicarbonyl as linkers between the lactam and the pyrrole ring, placed electron-withdrawing groups on the pyrrole ring, and substituted acyclic amide for lactam.In addition, we replaced the pyrrole segment with other heterocycles including thiophene, furan, isoxazole, isoxazoline, and pyridine.Generally, replacemcent of the N-methylpyrrole segment with thiophene, furan, isoxazoline, or pyridine afforded compounds equipotent with 1 in CAR, which were more stable in dilute acid.In the case of side chain or lactam modifications, CAR activity was significantly decreased or abolished, with the exception of 6.For the most part, the modifications to 1 resulted in the decrease or loss of D2 receptor binding.However, within this series, 5-HT1A receptor binding was greatly increased, with thiophene 40 exhibiting an IC50 of 0.07 nM.The CAR activities of pyrroles 6 and 12, thiophene 40, furans 44-47, isoxazolines 49 and 50, pyridine 54 coupled with their weak or nonexistent D2 binding and strong 5-HT1A binding suggest that they may be acting via a nondopaminergic mechanism or that dopaminergic active metabolites are responsible.Pyrrole 6 and furans 44 and 47 show promise as antipsychotic agents based on their CAR activity, receptor-binding profile, and solution stability.
