(E)-tert-Butyl 4-(N′-hy­droxy­carbam­­imid­o­yl)piperazine-1-carboxyl­ate

S Sreenivasa; K E Manojkumar; P A Suchetan; N R Mohan; B S Palakshamurthy

doi:10.1107/S1600536812046223

. 2012 Nov 14;68(Pt 12):o3347. doi: 10.1107/S1600536812046223

(E)-tert-Butyl 4-(N′-hydroxycarbamimidoyl)piperazine-1-carboxylate

S Sreenivasa ^a,^*, K E Manojkumar ^a, P A Suchetan ^b, N R Mohan ^a, B S Palakshamurthy ^c

PMCID: PMC3588948 PMID: 23476184

Abstract

In the title compound, C₁₀H₂₀N₄O₃, the piperazine ring adopts a chair conformation. The molecule adopts an E conformation across the C=N double bond, with the –OH group and the piperazine ring trans to one another. Further, the H atom of the hydroxy group is directed away from the NH₂ group. An intramolecular N—H⋯O contact occurs involving the NH₂ group and the oxime O atom. In the crystal, molecules are linked via strong N—H⋯O and O—H⋯N hydrogen bonds with alternating R ₂ ²(6) and C(9) motifs into tetrameric units forming R ₄ ⁴(28) motifs.

Related literature

For the synthesis, characterization and biological activity of piperazine and its derivatives, see: Gan et al. (2009a ▶,b ▶); Willems & Ilzerman (2010 ▶). For a related structure, see: Gowda et al. (2009 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶); Etter (1990 ▶). graphic file with name e-68-o3347-scheme1.jpg

Experimental

Crystal data

C₁₀H₂₀N₄O₃
M _r = 244.3
Triclinic,
a = 8.1923 (17) Å
b = 8.7859 (16) Å
c = 9.714 (2) Å
α = 109.451 (7)°
β = 99.540 (7)°
γ = 96.474 (7)°
V = 639.5 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 300 K
0.22 × 0.16 × 0.1 mm

Data collection

Bruker SMART X2S diffractometer
6407 measured reflections
2218 independent reflections
1632 reflections with I > 2σ(I)
R _int = 0.027

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.130
S = 1.05
2218 reflections
162 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: SMART (Bruker, 2004 ▶); cell refinement: SAINT-Plus (Bruker, 2004 ▶); data reduction: SAINT-Plus and XPREP (Bruker, 2004 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 2012 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Click here for additional data file.^{(16.8KB, cif)}

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812046223/zj2096sup1.cif

e-68-o3347-sup1.cif^{(16.8KB, cif)}

Click here for additional data file.^{(109KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812046223/zj2096Isup2.hkl

e-68-o3347-Isup2.hkl^{(109KB, hkl)}

Click here for additional data file.^{(1.7KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536812046223/zj2096Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2D⋯O1	0.94 (3)	2.08 (3)	2.538 (2)	108.3 (19)
N2—H2C⋯O2ⁱ	0.89 (3)	2.10 (3)	2.988 (2)	173 (3)
O1—H1⋯N1ⁱⁱ	0.82	2.04	2.764 (3)	147

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

The authors thank Dr S. C. Sharma, Vice Chancellor, Tumkur University, Tumkur for his constant encouragement. and G. B. Sadananda, Department of Studies and Research in Physics, U. C. S. Tumkur University, Tumkur, for his help and valuable suggestions. BSPM thanks Dr H. C. Devarajegowda, Department of Physics Yuvarajas College (constituent), University of Mysore, for his guidance.

supplementary crystallographic information

Comment

Numerous piperazine derivatives like aryl amide, sulphonamides, Mannich bases, Schiff's bases, thiazolidinones, azetidinones, imidazolinones have shown a wide spectrum of biological activities viz. antiinflammatory, antibacterial, antimalarial, anticonvulsant, antipyretic, antitumor, anthelmintics, analgesic, antidepressant, antifungal, antitubercular, anticancer, antidiabetic etc. In this view, we synthesized the title compound to study its crystal structure. The molecule crystallizes in triclinic P-1 space group. The piperazine ring in the molecule adopts chair conformation and the molecule prefers E configuration across the C—N double bond, as the OH group and the piperazine ring are in the opposite side of the double bond (Figure 1). The hydrogen atom of the hydroxyl group is directed away from the NH₂ group. This results in stabilizing the structure through a strong intermolecular O—H···N(1) and an intramolecular N(2)—H···O hydrogen bonds. In addition to this, the molecule also exhibits a strong N(2)—H···O(C) intermolecular hydrogen bond. The molecules are connected through alternate R₂²(6) ring and C(9) chain hydrogen bond patterns into tetrameric units exhibiting R₄⁴(28) ring patterns (Figure 2). The average N—C bond length in the piperazine ring is 1.466 Å indicating the single bond nature. While, the N4—C(O) bond length is 1.359 (2) Å indicating the delocalization of the nitrogen lone pair of electrons into π system of the carbonyl group. The N(1)—C(1) bond length is 1.290 Å due to its double bond nature, but the N(3)—C(1) and N(2)—C(1) bond lengths are closer to N—C(O) lengths indicating the partial double bond nature of these bonds.

Experimental

To a solution of N-boc-piperazine (10.6 mmol) in 20 ml of acetonitrile was added cyanogen bromide (10.7 mmol) and K₂CO₃ (21.2 mmol) at -10°C. The reaction mixture was stirred for 18 h at room temperature under nitrogen atmosphere. N-Cyano-4-boc-piperazine was obtained. To N-cyano-4-boc-piperazine (4.6 mmol) in methanol was added NH₂OH.HCl (9.3 mmol) and stirred for 30 min at room temperature. The solvent was removed under reduced pressure and the crude product was washed with cold water and dried to yield white solid product. Single crystals employed in X-ray diffraction studies were obtained from slow evaporation of the solution of the compound in methanol.