56233-34-2Relevant academic research and scientific papers
Reactions of acetylenic acid esters with piperazine derivatives
M?hrle, Hans,Azodi, Katja
, p. 1021 - 1034 (2008/09/16)
Hg(II)-EDTA-dehydrogenation of benzylpiperazine (5) in 50% ethanol with addition of diethyl acetylenedicarboxylate (2) to a minor extent gives rise to (piperazine-1,4-diyl)-bis(maleate) (9), which is inert to Hg(II)-EDTA and results in quantitative yield when Hg(II)-EDTA is omitted. 4-Benzylpiperazin-1- yl)-monomaleate (8) reacts with 2 in various solvents by addition of water with dealkylation and formation of 9. CH-acidic compounds may also be used as proton donors. Analogous reactions, although with minor yields, occur with the propiolates 11 and 12. 1-Substituted piperazines with benzyl, methine or allylic groups (5-5c, 27d-g, and 27h) react readily with acetylenedicarboxylic acid esters to give compounds of type 9, whereas benzhydryl, aromatic and most of the unbranched aliphatic substituents are not replaced. The reactivity of 1,4-disubstituted piperazines corresponds largely to the behaviour of the substituents in the monosubstituted derivatives.
Biologically Active Compounds through Catalysis: Efficient Synthesis of N-(Heteroarylcarbonyl)-N′-(arylalkyl)piperazines
Kumar, Kamal,Michalik, Dirk,Castro, Ivette Garcia,Tillack, Annegret,Zapf, Alexander,Arlt, Michael,Heinrich, Timo,Boettcher, Henning,Beller, Matthias
, p. 746 - 757 (2007/10/03)
A practical route for the synthesis of new biologically active 5-HT 2A receptor antagonists has been developed. In only three catalytic steps, this class of central nervous system (CNS) active compounds can be synthesized efficiently with high diversity. As the initial step, an anti-Markovnikov addition of amines to styrenes provides an easy route to N-(arylalkyl)piperazines, which constitute the core structure of the active molecules. Here, base-catalyzed hydroamination reactions of styrenes with benzylated piperazine proceeded in high yield even at room temperature. After catalytic debenzylation, the free amines were successfully carbonylated with different aromatic and heteroaromatic halides and carbon monoxide to yield the desired compounds in good to excellent yields. The two key reactions, base-catalyzed hydroamination of styrenes and palladium-catalyzed aminocarbonylation of haloarenes/heterocycles, showed tolerance towards various functional groups, thereby demonstrating the potential to synthesize a wide variety of new derivatives of this promising class of pharmaceuticals.
INHIBITORS OF FUNGAL INVASION
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Drawing sheet 8, (2010/02/09)
This invention relates to various anti-fungall agents including agents that are inhibitors of fungal invasion.
