3-[(R)-1-Hy­droxy­butan-2-yl]-1,2,3-benzo­triazin-4(3H)-one

Rocha-Alonzo, F.; Morales-Morales, D.; Hernández-Ortega, S.; Reyes-Martínez, R.; Parra-Hake, M.

doi:10.1107/S1600536812043802

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 68| Part 11| November 2012| Pages o3240-o3241

doi:10.1107/S1600536812043802

Open

access

3-[(R)-1-Hydroxybutan-2-yl]-1,2,3-benzotriazin-4(3H)-one

Fernando Rocha-Alonzo,^a ^* David Morales-Morales,^b Simón Hernández-Ortega,^b Reyna Reyes-Martínez ^b and Miguel Parra-Hake ^c ^*

^aDepartamento de Ciencias Químico Bilógicas, Universidad de Sonora, Hermosillo, Sonora, 83000 México, ^bInstituto de Química, Universidad Nacional Autónoma de México, Circuito exterior, Ciudad Universitaria, México D.F., 04510 México, and ^cCentro de Graduados e Investigación, Instituto Tecnológico de Tijuana, Tijuana, B.C., 22500 México
^*Correspondence e-mail: fernando.rocha@guayacan.uson.mx, miguelhake@yahoo.com

(Received 21 October 2012; accepted 22 October 2012; online 31 October 2012)

The crystal structure of the title compound, C₁₁H₁₃N₃O₂, is stabilized by O—H⋯O hydrogen bonds, which link the molecules into chains along [100].

Related literature

For biological and synthetic applications of benzo-1,2,3-triazinones, see: Caliendo et al. (1999 ); Zheng et al. (2005 ); Vaisburg et al. (2004 ); Chollet et al. (2002 ); Le Diguarher et al. (2003 ); Clark et al. (1995 ); Carpino et al. (2004 ); Janout et al. (2003 ); Gierasch et al. (2000 ). For structures of benzo-1,2,3-triazinones, see: Hjortås et al. (1973 ); Hunt et al. (1983 ); Reingruber et al. (2009 ). For bond-length data, see: Allen et al. (1987 ). For the synthesis, see: Gómez et al. (2005 ).

Experimental

Crystal data

C₁₁H₁₃N₃O₂
M_r = 219.24
Orthorhombic, P 2₁ 2₁ 2₁
a = 8.9668 (13) Å
b = 10.1506 (15) Å
c = 12.0238 (17) Å
V = 1094.4 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 298 K
0.32 × 0.10 × 0.10 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
9057 measured reflections
2000 independent reflections
1700 reflections with I > 2σ(I)
R_int = 0.044

Refinement

R[F² > 2σ(F²)] = 0.034
wR(F²) = 0.076
S = 0.93
2000 reflections
149 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.11 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯O1ⁱ	0.85 (1)	2.03 (1)	2.8712 (19)	171 (2)
Symmetry code: (i) $[x+{\script{1\over 2}}, -y+{\script{3\over 2}}, -z+2]$ .

Data collection: SMART (Bruker, 2007 ); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536812043802/zj2097sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812043802/zj2097Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812043802/zj2097Isup3.cml

checkCIF report

Comment top

Benzo-1,2,3-triazinones are compounds widely investigated for their potential biological and chemical properties. These heterocyclic compounds have been studied as anesthetic (Caliendo et al., 1999), anti-inflammatory (Zheng et al., 2005), anticancer (Vaisburg et al.., 2004; Chollet et al., 2002), and antitumoural (Le Diguarher et al., 2003; Clark et al., 1995) agents. In organic synthesis, 1,2,3-triazinones are used as an activating moiety in coupling agents for the preparation of peptides and amino acids (Carpino et al., 2004; Janout et al., 2003; Gierasch et al., 2000). As result of its biological and synthetic importance, we have developed an alternative method for obtaining compounds with 1,2,3-triazinone moiety and in this paper we are describing the crystal structure of the title compound (I, Figure 1).

In the molecular structure of I, the N1=N2 bond [1.2636 (17) Å] is longer than the typical values for N=N double bonds (1.236 Å), whereas the N2–N3 bond [1.3735 (18) Å] is shorter than typical values for a N–N single bonds (1.404 Å) (Allen et al.., 1987). The structure of I shows co-planarity between two rings (1.30°). These measurements are in agreement with other benzo-1,2,3-triazinone crystal structure reports (Hjortås et al., 1973; Hunt et al., 1983; Reingruber et al., 2009). Of interest to pharmaceutical applications, it has been suggested that co-planar structure in benzo-1,2,3-triazinones could give DNA-intercalating abilities such as those displayed by some anticancer agents (Reingruber et al., 2009).

In the crystal structure, adjacent units are arranged into one-dimensional chain along [100] direction via O–H···O intermolecular hydrogen bonds (Figure 2 and Table 1).

Related literature top

For biological and synthetic applications of benzo-1,2,3-triazinones, see: Caliendo et al. (1999); Zheng et al. (2005); Vaisburg et al. (2004); Chollet et al. (2002); Le Diguarher et al. (2003); Clark et al. (1995); Carpino et al. (2004); Janout et al. (2003); Gierasch et al. (2000). For structures of benzo-1,2,3-triazinones, see: Hjortås et al. (1973); Hunt et al. (1983); Reingruber et al. (2009). For bond-length data, see: Allen et al. (1987). For the synthesis, see: Gómez et al. (2005).

Experimental top

The synthesis of the tittle compound included reagents and solvents of reagent grade, which were used without further purification. To a solution of 2-[(4R)-4-ethyl-4,5-dihydro-1,3-oxazol-2-yl]aniline (Gómez et al., 2005) (0.89 g, 4.7 mmol, dissolved in 85 ml of methanol) was slowly added isoamyl nitrite (4.40 g, 37.6 mmol, 8 equiv) and the reaction mixture was stirred at room temperature until the disappearance of the aniline (followed by TLC, hexane/ethyl acetate, 3:1). The solvent was evaporated under reduced pressure to give a crude product that was purified by washing with petroleum ether and recrystallization from hexane/ethyl acetate. Crystalline colorless prisms of I were grown by slow diffusion of hexane over saturated ethyl acetate solutions of I. Yield > 99%, based on 2-[(4R)-4-Ethyl-4,5-dihydro-1,3-oxazol-2-yl]aniline; m.p., 89–90 °C. = -5.45° (c 0.22, MeOH). FTIR (KBr pellet, cm^-1): 3439, 1686, 1663, 1296. ¹H NMR [(CD₃)₂CO, 200 MHz] d 8.29 (ddd, J = 0.6, 1.5, 7.9 Hz, 2H), 8.16 (ddd, J = 0.6, 1.5, 8.1 Hz, 2H), 8.07 (ddd, J = 1.5, 7.0, 8.2 Hz, 2H), 7.91 (ddd,, J = 1.5, 7.0, 7.9 Hz, 2H), 5.22 (ddd, J = 5.1, 7.6, 15.5 Hz, 2H), 4.10 (dd, J = 8.4, 11.3 Hz, 2H), 3.96 (dd, J = 5.1, 11.3 Hz, 2H), 1.99 (dd, J = 7.5, 15.0 Hz, 4H), 0.90 (t, J = 7.4 Hz, 6H). ¹³C NMR [(CD₃)₂CO, 50 MHz] d 156.6, 144.5, 135.8, 133.2, 128.8, 125.7, 120.3, 64.2, 62.3, 24.2, 10.8. ESI-HRMS:220.1091 (100), calculated for [M+H]⁺, C₁₁H₁₄N₃O₂⁺, 220.1081; 192.1025 (8), calculated for [M+H—N₂]⁺, C₁₁H₁₄NO₂⁺, 192.1019. Anal for C₁₁H₁₃N₃O₂ (% Calcd./found) C, 60.26/60.73; H, 5.98/6.45; N, 19.17/19.47.

Computing details top

Data collection: SMART (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. Molecular structure of (I) with displacement ellipsoids drawn at 50% probability.
	Fig. 2. Packing of I showing the H-bonds. The molecules are forming a one-dimensional chain in the [100] direction. H-bonds are indicated by dashed lines.

3-[(R)-1-Hydroxybutan-2-yl]-1,2,3-benzotriazin-4(3H)-one top

Crystal data top

C₁₁H₁₃N₃O₂	F(000) = 464
M_r = 219.24	D_x = 1.331 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 4276 reflections
a = 8.9668 (13) Å	θ = 2.6–25.2°
b = 10.1506 (15) Å	µ = 0.09 mm⁻¹
c = 12.0238 (17) Å	T = 298 K
V = 1094.4 (3) Å³	Prism, colourless
Z = 4	0.32 × 0.10 × 0.10 mm

Data collection top

Bruker SMART APEX CCD area-detector diffractometer	1700 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.044
Graphite monochromator	θ_max = 25.4°, θ_min = 2.6°
Detector resolution: 0.83 pixels mm^-1	h = −10→10
ω scans	k = −12→12
9057 measured reflections	l = −14→14
2000 independent reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.076	H atoms treated by a mixture of independent and constrained refinement
S = 0.93	w = 1/[σ²(F_o²) + (0.0412P)²] where P = (F_o² + 2F_c²)/3
2000 reflections	(Δ/σ)_max < 0.001
149 parameters	Δρ_max = 0.11 e Å⁻³
1 restraint	Δρ_min = −0.15 e Å⁻³

Crystal data top

C₁₁H₁₃N₃O₂	V = 1094.4 (3) Å³
M_r = 219.24	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 8.9668 (13) Å	µ = 0.09 mm⁻¹
b = 10.1506 (15) Å	T = 298 K
c = 12.0238 (17) Å	0.32 × 0.10 × 0.10 mm

Data collection top

Bruker SMART APEX CCD area-detector diffractometer	1700 reflections with I > 2σ(I)
9057 measured reflections	R_int = 0.044
2000 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.034	1 restraint
wR(F²) = 0.076	H atoms treated by a mixture of independent and constrained refinement
S = 0.93	Δρ_max = 0.11 e Å⁻³
2000 reflections	Δρ_min = −0.15 e Å⁻³
149 parameters

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.56004 (14)	0.68985 (11)	1.02583 (10)	0.0584 (4)
N1	0.87770 (16)	0.64809 (13)	0.79106 (11)	0.0438 (4)
O2	0.82337 (18)	0.99854 (13)	0.99816 (15)	0.0797 (5)
H2	0.885 (2)	0.9362 (16)	0.992 (2)	0.096*
N2	0.80536 (16)	0.75426 (13)	0.80106 (11)	0.0430 (4)
N3	0.70312 (14)	0.76906 (12)	0.88520 (11)	0.0372 (3)
C4	0.66320 (18)	0.67321 (15)	0.96026 (14)	0.0386 (4)
C4A	0.75154 (18)	0.55429 (16)	0.95179 (13)	0.0362 (4)
C5	0.7338 (2)	0.44941 (16)	1.02537 (14)	0.0469 (4)
H5	0.6642	0.4546	1.0826	0.056*
C6	0.8194 (2)	0.33848 (17)	1.01301 (16)	0.0545 (5)
H6	0.8081	0.2686	1.0623	0.065*
C7	0.9226 (2)	0.32979 (18)	0.92741 (17)	0.0568 (5)
H7	0.9790	0.2535	0.9191	0.068*
C8	0.94229 (19)	0.43244 (17)	0.85511 (16)	0.0517 (5)
H8	1.0127	0.4266	0.7985	0.062*
C8A	0.85625 (17)	0.54564 (15)	0.86684 (13)	0.0382 (4)
C9	0.62783 (18)	0.89954 (14)	0.88408 (15)	0.0420 (4)
H9	0.5594	0.9021	0.9476	0.050*
C10	0.7406 (2)	1.00892 (17)	0.89991 (17)	0.0553 (5)
H10A	0.8088	1.0088	0.8372	0.066*
H10B	0.6886	1.0927	0.8998	0.066*
C11	0.5352 (2)	0.91729 (17)	0.77929 (16)	0.0559 (5)
H11A	0.4838	1.0012	0.7833	0.067*
H11B	0.6015	0.9202	0.7156	0.067*
C12	0.4222 (2)	0.80997 (19)	0.76146 (19)	0.0765 (7)
H12A	0.3540	0.8081	0.8230	0.092*
H12B	0.4722	0.7266	0.7560	0.092*
H12C	0.3681	0.8266	0.6940	0.092*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0643 (8)	0.0449 (7)	0.0660 (9)	0.0042 (7)	0.0294 (8)	0.0035 (6)
N1	0.0471 (8)	0.0409 (8)	0.0434 (8)	0.0020 (7)	0.0101 (7)	−0.0012 (7)
O2	0.0754 (11)	0.0612 (10)	0.1026 (12)	0.0097 (8)	−0.0365 (10)	−0.0201 (9)
N2	0.0473 (8)	0.0401 (8)	0.0415 (8)	0.0014 (7)	0.0075 (7)	0.0013 (7)
N3	0.0410 (8)	0.0319 (7)	0.0387 (8)	0.0029 (6)	0.0047 (7)	0.0002 (6)
C4	0.0396 (9)	0.0364 (9)	0.0398 (9)	−0.0021 (8)	0.0043 (8)	−0.0018 (8)
C4A	0.0380 (9)	0.0339 (8)	0.0366 (9)	−0.0030 (7)	−0.0024 (8)	−0.0013 (7)
C5	0.0532 (11)	0.0426 (10)	0.0448 (10)	−0.0046 (9)	−0.0004 (9)	0.0019 (8)
C6	0.0638 (12)	0.0392 (10)	0.0604 (12)	−0.0009 (9)	−0.0109 (10)	0.0083 (9)
C7	0.0538 (12)	0.0365 (10)	0.0800 (14)	0.0100 (9)	−0.0071 (11)	−0.0013 (10)
C8	0.0435 (10)	0.0465 (11)	0.0651 (12)	0.0061 (9)	0.0060 (9)	−0.0089 (10)
C8A	0.0379 (9)	0.0352 (9)	0.0416 (10)	−0.0030 (7)	−0.0017 (8)	−0.0044 (8)
C9	0.0457 (9)	0.0337 (9)	0.0467 (10)	0.0058 (7)	0.0009 (9)	−0.0019 (8)
C10	0.0587 (11)	0.0362 (10)	0.0711 (12)	0.0034 (8)	−0.0022 (12)	−0.0055 (9)
C11	0.0648 (12)	0.0429 (10)	0.0600 (12)	0.0132 (9)	−0.0118 (10)	−0.0007 (9)
C12	0.0765 (14)	0.0602 (13)	0.0927 (17)	0.0111 (12)	−0.0357 (14)	−0.0133 (12)

Geometric parameters (Å, º) top

O1—C4	1.2271 (18)	C7—C8	1.368 (2)
N1—N2	1.2636 (17)	C7—H7	0.9300
N1—C8A	1.396 (2)	C8—C8A	1.391 (2)
O2—C10	1.399 (2)	C8—H8	0.9300
O2—H2	0.846 (9)	C9—C10	1.514 (2)
N2—N3	1.3735 (18)	C9—C11	1.520 (2)
N3—C4	1.3745 (19)	C9—H9	0.9800
N3—C9	1.4866 (19)	C10—H10A	0.9700
C4—C4A	1.447 (2)	C10—H10B	0.9700
C4A—C8A	1.390 (2)	C11—C12	1.503 (2)
C4A—C5	1.393 (2)	C11—H11A	0.9700
C5—C6	1.371 (2)	C11—H11B	0.9700
C5—H5	0.9300	C12—H12A	0.9600
C6—C7	1.387 (3)	C12—H12B	0.9600
C6—H6	0.9300	C12—H12C	0.9600

N2—N1—C8A	120.17 (13)	C8—C8A—N1	118.22 (15)
C10—O2—H2	109.5 (17)	N3—C9—C10	110.42 (13)
N1—N2—N3	120.40 (12)	N3—C9—C11	111.17 (14)
N2—N3—C4	125.45 (12)	C10—C9—C11	112.49 (14)
N2—N3—C9	113.20 (12)	N3—C9—H9	107.5
C4—N3—C9	121.22 (13)	C10—C9—H9	107.5
O1—C4—N3	121.38 (14)	C11—C9—H9	107.5
O1—C4—C4A	124.93 (15)	O2—C10—C9	113.91 (15)
N3—C4—C4A	113.68 (14)	O2—C10—H10A	108.8
C8A—C4A—C5	119.70 (15)	C9—C10—H10A	108.8
C8A—C4A—C4	118.29 (14)	O2—C10—H10B	108.8
C5—C4A—C4	122.01 (15)	C9—C10—H10B	108.8
C6—C5—C4A	119.66 (17)	H10A—C10—H10B	107.7
C6—C5—H5	120.2	C12—C11—C9	113.63 (15)
C4A—C5—H5	120.2	C12—C11—H11A	108.8
C5—C6—C7	120.42 (17)	C9—C11—H11A	108.8
C5—C6—H6	119.8	C12—C11—H11B	108.8
C7—C6—H6	119.8	C9—C11—H11B	108.8
C8—C7—C6	120.59 (17)	H11A—C11—H11B	107.7
C8—C7—H7	119.7	C11—C12—H12A	109.5
C6—C7—H7	119.7	C11—C12—H12B	109.5
C7—C8—C8A	119.55 (17)	H12A—C12—H12B	109.5
C7—C8—H8	120.2	C11—C12—H12C	109.5
C8A—C8—H8	120.2	H12A—C12—H12C	109.5
C4A—C8A—C8	120.07 (15)	H12B—C12—H12C	109.5
C4A—C8A—N1	121.71 (14)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1ⁱ	0.85 (1)	2.03 (1)	2.8712 (19)	171 (2)

Symmetry code: (i) x+1/2, −y+3/2, −z+2.

Experimental details

Crystal data
Chemical formula	C₁₁H₁₃N₃O₂
M_r	219.24
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	298
a, b, c (Å)	8.9668 (13), 10.1506 (15), 12.0238 (17)
V (Å³)	1094.4 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.32 × 0.10 × 0.10

Data collection
Diffractometer	Bruker SMART APEX CCD area-detector diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	9057, 2000, 1700
R_int	0.044
(sin θ/λ)_max (Å⁻¹)	0.603

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.034, 0.076, 0.93
No. of reflections	2000
No. of parameters	149
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.11, −0.15

Computer programs: SMART (Bruker, 2007), SAINT (Bruker, 2007), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1ⁱ	0.846 (9)	2.033 (11)	2.8712 (19)	171 (2)

Symmetry code: (i) x+1/2, −y+3/2, −z+2.

Acknowledgements

We gratefully acknowledge support for this project by the Consejo Nacional de Ciencia y Tecnología (CONACyT grant 36435-E) and Consejo del Sistema Nacional de Educación Tecnológica (COSNET) grant 486–02-P. The authors are indebted to Adrián Ochoa Terán and Ignacio Rivero Espejel for their analytical support of this work.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, V., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CrossRef Google Scholar
Bruker (2007). SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Caliendo, G., Fiorino, F., Grieco, P., Perissutti, E., Santagada, V., Meli, R., Mattace-Raso, G., Zanesco, A. & De Nucci, G. (1999). Eur. J. Med. Chem. 34, 1043–1051. Web of Science CrossRef CAS Google Scholar
Carpino, L. A., Xia, J., Zhang, C. & El-Faham, A. (2004). J. Org. Chem. 69, 62–71. Web of Science CrossRef PubMed CAS Google Scholar
Chollet, A. M., Le Diguarher, T., Kucharczyk, N., Oynel, A., Bertrand, M., Tucker, G., Guilbaud, N., Burbridge, M., Pastoureau, P., Fradin, A., Sabatini, M., Fauchére, J.-L. & Casara, P. (2002). Bioorg. Med. Chem. 10, 531–544. Web of Science CrossRef PubMed CAS Google Scholar
Clark, A. S., Deans, B., Stevens, M. F. G., Tisdale, M. J., Wheelhouse, R. T., Denny, B. J. & Hartley, J. A. (1995). J. Med. Chem. 38, 1493–1504. CrossRef CAS PubMed Web of Science Google Scholar
Gierasch, T. M., Chytil, M., Didiuk, M. T., Park, J. Y., Urban, J. J., Nolan, S. P. & Verdine, G. L. (2000). Org. Lett. 2, 3999–4002. Web of Science CrossRef PubMed CAS Google Scholar
Gómez, M., Jansat, S., Muller, G., Aullón, G. & Maestro, M. A. (2005). Eur. J. Inorg. Chem. pp. 4341–4351. Google Scholar
Hjortås, J. (1973). Acta Cryst. B29, 1916–1922. CSD CrossRef IUCr Journals Web of Science Google Scholar
Hunt, W. E., Schwalbe, C. H. & Vaughan, K. (1983). Acta Cryst. C39, 738–740. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Janout, V., Jing, B., Staina, I. V. & Regen, S. L. (2003). J. Am. Chem. Soc. 125, 4436–4437. Web of Science CrossRef PubMed CAS Google Scholar
Le Diguarher, T., Chollet, A. M., Bertrand, M., Henning, P., Raimbaud, E., Sabatini, M. N., Guilbaud, N., Pierré, A., Tucker, G. C. & Casara, P. (2003). J. Med. Chem. 46, 3840–3852. Web of Science CrossRef PubMed CAS Google Scholar
Reingruber, R., Vanderheiden, S., Muller, T., Nieger, M., Es-Sayed, M. & Bräse, S. (2009). Tetrahedron Lett. 50, 3439–3442. Web of Science CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Vaisburg, A., Bernstein, N., Frechette, S., Allan, M., Abou-Khalil, E., Leit, S., Moradei, O., Bouchain, G., Wang, J., Hyung Woo, S., Fournel, M., Yan, P. T., Trachy-Bourget, M.-C., Kalita, A., Beaulieu, C., Li, Z., MacLeod, A. R., Bestermanb, J. M. & Delormea, D. (2004). Bioorg. Med. Chem. Lett. 14, 283–287. Web of Science CrossRef PubMed CAS Google Scholar
Zheng, G. Z., Bhatia, P., Daanen, J., Kolasa, T., Patel, M., Latshaw, S., El Kouhen, O. F., Chang, R., Uchic, M. E., Miller, L., Nakane, M., Lehto, S. J., Honore, M. P., Moreland, R. B., Brioni, J. D. & Stewart, A. O. (2005). J. Med. Chem. 48, 7374–7388. Web of Science CrossRef PubMed CAS Google Scholar