- Structure-Activity Relationship Studies on Oxazolo[3,4- a]pyrazine Derivatives Leading to the Discovery of a Novel Neuropeptide S Receptor Antagonist with Potent in Vivo Activity
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Neuropeptide S modulates important neurobiological functions including locomotion, anxiety, and drug abuse through interaction with its G protein-coupled receptor known as neuropeptide S receptor (NPSR). NPSR antagonists are potentially useful for the treatment of substance abuse disorders against which there is an urgent need for new effective therapeutic approaches. Potent NPSR antagonists in vitro have been discovered which, however, require further optimization of their in vivo pharmacological profile. This work describes a new series of NPSR antagonists of the oxazolo[3,4-a]pyrazine class. The guanidine derivative 16 exhibited nanomolar activity in vitro and 5-fold improved potency in vivo compared to SHA-68, a reference pharmacological tool in this field. Compound 16 can be considered a new tool for research studies on the translational potential of the NPSergic system. An in-depth molecular modeling investigation was also performed to gain new insights into the observed structure-activity relationships and provide an updated model of ligand/NPSR interactions.
- Albanese, Valentina,Ruzza, Chiara,Marzola, Erika,Bernardi, Tatiana,Fabbri, Martina,Fantinati, Anna,Trapella, Claudio,Reinscheid, Rainer K.,Ferrari, Federica,Sturaro, Chiara,Calò, Girolamo,Amendola, Giorgio,Cosconati, Sandro,Pacifico, Salvatore,Guerrini, Remo,Preti, Delia
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p. 4089 - 4108
(2021/04/12)
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- Synthesis of Enantiopure Piperazines via Asymmetric Lithiation-Trapping of N-Boc Piperazines: Unexpected Role of the Electrophile and Distal N-Substituent
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A new method for the synthesis of enantiopure α-substituted piperazines via direct functionalization of the intact piperazine ring is described. The approach utilizes the asymmetric lithiation-substitution of an α-methylbenzyl-functionalized N-Boc piperaz
- Firth, James D.,O'Brien, Peter,Ferris, Leigh
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p. 651 - 659
(2016/01/29)
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- Synthesis of new polysubstituted piperazines and dihydro-2H-pyrazines by selective reduction of 2-oxo-piperazines
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New enantiomerically enriched 1,4,5-piperazines and 1,4,5-dihydro-2H-pyrazines have been prepared by reduction of the corresponding 2-oxo-piperazines. Selective reduction can be achieved by careful control of the reaction conditions using LiAlH4/sub
- Reginato, Gianna,Credico, Barbara Di,Andreotti, Daniele,Mingardi, Anna,Paio, Alfredo,Donati, Daniele,Pezzati, Bernardo,Mordini, Alessandro
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experimental part
p. 191 - 194
(2010/05/18)
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- A novel and facile method to synthesize (R)- and (S)-2-methylpiperazine
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A concise and efficient synthesis of (R)- and (S)-2-methylpiperazine in only five steps from (D)- and (L)-alanine is described. The key step is reaction of benzylamine with a bifunctional molecule to build a six-membered ring.
- Liu, Bo,Xu, Guang-Yu,Yang, Chun-Hao,Wu, Xi-Han,Xie, Yu-Yuan
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p. 4111 - 4118
(2007/10/03)
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- PIPERAZINE UREA DERIVATIVES AS MELANOCORTIN-4 RECEPTOR AGONISTS
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Certain novel piperazine urea derivatives are agonists of the human melanocortin-4 receptor (MC-4R) and, in particular, are receptor-subtype selective agonists of MC-4R. They are useful for the treatment, control, or prevention of diseases and disorders r
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- Inhibitors of farnesyl-protein transferase
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The present invention is directed to compounds which inhibit farnesyl-protein transferase (FTase) and the farnesylation of the oncogene protein Ras. The invention is further directed to chemotherapeutic compositions containing the compounds of this invention and methods for inhibiting farnesyl-protein transferase and the farnesylation of the oncogene protein Ras. The compounds of formula A are representative of the compounds of the present invention: STR1
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- Asymmetric Synthesis of 2,6-Methylated Piperazines
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The complete series of enantiopure 2,6-methylated piperazines was synthesized utilizing two alternative reactions in the key bond-forming step.The dimethyl enantiomers, (2R,6R)- and (2S,6S)-2,6-dimethylpiperazine (1, 2), were prepared using either a diastereoselective triflate alkylation or a novel intermolecular Mitsunobu reaction to set the required stereochemistry.The monomethyl derivatives, (R)- and (S)-tert-butyl 2-methyl-1-piperazinecarboxylate (3, 4) were also synthesized employing the Mitsunobu cyclization strategy while the trimethyl compounds, (R)- and (S)-2,2,6- trimethylpiperazine (5, 6) were prepared using an enantiospecific triflate alkylation as the principal reaction.These methods represent efficient, general strategies for preparing a variety of 2,6-methylated piperazines for which the absolute stereochemistry can be readily controlled.
- Mickelson, John W.,Belonga, Kenneth L.,Jacobsen, Jon E.
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p. 4177 - 4183
(2007/10/02)
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