Synthesis and Crystal Structures of N,N0-Disubstituted Piperazines
نویسندگان
چکیده
The structure of 1,4-diphenylpiperazine (1) was determined; it crystallized in the orthorhombic space group Pbca, a = 8.6980(7), b = 8.4287(7), c = 17.6359(15), V = 1292.94(19), Z = 4. Three novel N,N0-disubstituted piperazines were synthesized via reductive amination of piperazine or N-diphenylmethylpiperazine. The products were characterized by NMR and X-ray crystallography. 1,4Diphenethylpiperazine (2) crystallized in the monoclinic space group C2/c, a = 17.9064(13), b = 6.2517(5), c = 14.9869(11), b = 90.613(4), V = 1677.6(2), Z = 4. 1-Benzhydryl-4-benzylpiperazine (3) crystallized in the monoclinic space group Pn, a = 5.9450(2), b = 19.0722(4), c = 8.6084(2), b = 96.4600(10), V = 98.1790(10), Z = 2. 1-Benzhydryl-4-(pyridin-2-ylmethyl) piperazine (4) crystallized in the monoclinic space group P2/c, a = 13.5637(2), b = 5.82170(10), c = 24.0645(4), b = 90.613(4), V = 1888.16(5), Z = 4. Comparison of the structures showed significant sp character for the piperazine nitrogen atoms in 1. Each structure showed multiple intermolecular non-bonding interactions.
منابع مشابه
SnAP reagents for the synthesis of piperazines and morpholines.
Substituted piperazines and morpholines are valuable structural motifs in biologically active compounds, but are not easily prepared by contemporary cross-coupling approaches. In this report, we introduce SnAP reagents for the transformation of aldehydes into N-unprotected piperazines and morpholines. This approach offers simple, mild conditions compatible with aromatic, heteroaromatic, aliphat...
متن کاملModular, efficient synthesis of asymmetrically substituted piperazine scaffolds as potent calcium channel blockers.
A novel approach to the synthesis of substituted piperazines and their investigation as N-type calcium channel blockers is presented. A common scaffold exhibiting high activity as N-type blockers is N-substituted piperazine. Using recently developed titanium and zirconium catalysts, we describe the efficient and modular synthesis of 2,5-asymmetrically disubstituted piperazines from simple amine...
متن کاملOne-pot preparation of piperazines by regioselective ring-opening of non-activated arylaziridines.
Herein we report a new straightforward synthesis of cis and trans 2,5-disubstituted N,N-dialkylpiperazines, even in enantioenriched form, by reacting non-activated N-alkyl arylaziridines in the presence of a catalytic amount of a Lewis acid. A stereochemical and NMR investigation revealed useful mechanistic insights for this process.
متن کاملEfficient Synthesis of 5,5-Disubstituted Bis-hydantoins/spirohydantoins and a Tetrakis-analogue: A Drug-like Multi-cyclic Scaffold
An easy method was developed for the efficient preparation of diversely new 5,5-disubstituted N(3),N'(3)-linkaged bis-hydantoins. At first, using the same methods, some ketones and terephthalaldehyde were converted to several hydantoins and a new bis-hydantoin , respectively. Then 1,6-dibromohexane, as a mild reagent, was employed for the alkylation and incorporation of synthesized substrates t...
متن کاملHydrogen-Bonding Networks in Heterocyclic Thioureas
The synthesis of heterocyclic thioureas from heterocyclic amines with phenylor methylisothiocyanate or CS2 is described. Seven new X-ray crystal structures are reported: In N-(3-pyridyl)-N0-phenylthiourea (Pna21, a = 10.1453(3), b = 17.6183(5), c = 6.4787(2), V = 1158.02(6), Z = 4) hydrogen-bonding results in formation of a 3D network consisting of helices, which form channels parallel to the c...
متن کامل