Pifithrin-β

Clegg, W.; Jamieson, C.

doi:10.1107/S160053680501264X

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 61| Part 5| May 2005| Pages o1486-o1488

https://doi.org/10.1107/S160053680501264X

Pifithrin-β

William Clegg ^a ^* and Clare Jamieson ^a

^aSchool of Natural Sciences (Chemistry), University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU, England
^*Correspondence e-mail: w.clegg@ncl.ac.uk

(Received 20 April 2005; accepted 21 April 2005; online 27 April 2005)

The title compound, 2-p-tolyl-5,6,7,8-tetrahydrobenzo[d]imidazo[2,1-b]thiazole, C₁₆H₁₆N₂S, is a condensation product of pifithrin-α, which has been previously reported as an inhibitor of the tumour suppressor protein p53. The molecule contains a planar fused pair of heterocyclic five-membered rings and the attached p-tolyl substituent is also essentially coplanar.

Comment

The compound pifithrin-α [2-(2-imino-4,5,6,7-tetrahydrobenzothiazol-3-yl)-1-(4-methylphenyl)ethanone, (1)] was previously reported to inhibit, in vitro, a number of processes involving the tumour suppressor protein p53; it was thus of interest in the development of cancer therapies (Komarov et al., 1999 ). During a further evaluation of the effectiveness of pifithrin-α, a crystalline sample was obtained and its structure investigated by X-ray diffraction. However, the material was found to be a condensation product of pifithrin-α, from which water had been eliminated in a ring closure. The product, referred to as pifithrin-β, (2), is more stable than pifithrin-α in tissue culture medium. The revelation of this transformation through crystallographic identification of the condensation product has led to an expansion of the original evaluation of pifithrin-α to include also pifithrin-β, and the recognition that some of the inhibitory effects previously ascribed to pifithrin-α are probably due instead to pifithrin-β or a combination of the two compounds (Walton et al., 2005 ).

The molecule of pifithrin-β (Fig. 1) contains three fused rings with a p-tolyl substituent. The cyclohexene ring (or tetrahydrobenzo group) is disordered over two conformations, in which the two saturated C atoms furthest from the double bond lie one on each side of the mean plane of the other atoms of the ring [by 0.377 (4) and 0.375 (4) Å for the major component]; the two disorder components have opposite senses of twist for this CH₂CH₂ segment (see the torsion angles in Table 1). The fused thiazole and imidazole rings are individually planar (r.m.s. deviations < 0.003 Å) and form a single planar unit [r.m.s. deviation 0.009 Å; dihedral angle between the two five-membered rings = 1.32 (5)°]. Such imidazo[2,1-b]thiazole fused ring systems have been found in ten other crystal structures in the Cambridge Structural Database (Version 5.26 plus one update, February 2005; Allen, 2002 ), and they are all planar.

The benzene ring of the p-tolyl substituent makes a dihedral angle of 2.32 (5)° with the imidazole ring to which it is attached. The whole molecule, excluding H atoms and the disordered CH₂CH₂ linkage, is thus essentially planar, with an r.m.s. deviation of 0.039 Å. There are no notable intermolecular interactions in the crystal structure. The molecules lie in almost planar sheets parallel to (001) (Fig. 2).

Figure 1
The molecular structure of (2

) with atom labels and 50% probability ellipsoids for non-H atoms. The minor disorder component has been omitted.

Figure 2
The crystal packing, viewed along the a axis, showing almost planar sheets of molecules parallel to (001).

Experimental

The compound was prepared by a condensation reaction of pifithrin-α, initially unintentionally during a study of anti-tumour agents, and subsequently by refluxing in aqueous methanol (Walton et al., 2005). It was recrystallized from methanol.

Crystal data

C₁₆H₁₆N₂S
M_r = 268.37
Monoclinic, P2₁/c
a = 7.1729 (4) Å
b = 13.5386 (8) Å
c = 14.3530 (8) Å
β = 103.917 (2)°
V = 1352.92 (13) Å³
Z = 4
D_x = 1.318 Mg m⁻³
Mo Kα radiation
Cell parameters from 9390 reflections
θ = 2.1–28.5°
μ = 0.23 mm⁻¹
T = 160 (2) K
Block, colourless
0.44 × 0.30 × 0.26 mm

Data collection

Bruker SMART 1K CCD diffractometer
Thin-slice ω scans
Absorption correction: multi-scan (SADABS; Sheldrick, 2003 ) T_min = 0.91, T_max = 0.94
11454 measured reflections
3222 independent reflections
2871 reflections with I > 2σ(I)
R_int = 0.022
θ_max = 28.5°
h = −9 → 9
k = −17 → 17
l = −18 → 18

Refinement

Refinement on F²
R[F² > 2σ(F²)] = 0.038
wR(F²) = 0.103
S = 1.05
3222 reflections
192 parameters
H-atom parameters constrained
w = 1/[σ²(F_o²) + (0.0542P)² + 0.5147P] where P = (F_o² + 2F_c²)/3
(Δ/σ)_max < 0.001
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Table 1
Selected geometric parameters (Å, °)

N1—C1	1.3949 (17)
N1—C2	1.3147 (17)
N2—C2	1.3666 (16)
N2—C8	1.3991 (16)
N2—C9	1.3770 (17)
S1—C2	1.7391 (13)
S1—C3	1.7650 (14)
C1—C9	1.3760 (18)
C3—C8	1.3447 (19)

C1—N1—C2	103.49 (11)
C2—N2—C8	115.28 (11)
C2—N2—C9	106.49 (11)
C8—N2—C9	138.21 (11)
C2—S1—C3	90.36 (6)
N1—C1—C9	111.16 (11)
N1—C1—C10	121.52 (11)
C9—C1—C10	127.32 (12)
N1—C2—N2	113.56 (11)
N1—C2—S1	136.19 (10)
N2—C2—S1	110.23 (10)
S1—C3—C4	123.59 (10)
S1—C3—C8	112.18 (10)
C4—C3—C8	124.22 (13)
N2—C8—C3	111.96 (11)
N2—C8—C7	122.51 (11)
C3—C8—C7	125.52 (12)
N2—C9—C1	105.31 (11)

C3—C4—C5—C6	−45.8 (3)
C4—C5—C6—C7	64.3 (3)
C3—C4—C5X—C6X	47.9 (8)
C4—C5X—C6X—C7	−61.1 (10)
C5X—C6X—C7—C8	41.1 (9)
C5—C6—C7—C8	−45.5 (3)
N1—C1—C10—C15	−1.16 (19)
C9—C1—C10—C11	−1.5 (2)

H atoms were positioned geometrically (C—H = 0.95–0.99 Å) and refined with a riding model (including free rotation about the C—C bond for the methyl group), and with U_iso values constrained to be 1.2 (1.5 for methyl groups) times U_eq of the carrier atom. Twofold disorder was resolved and refined for the central CH₂CH₂ linkage of the cyclohexene ring, with occupancy factors 0.766 (6):0.234 (6).

Data collection: SMART (Bruker, 2001 ); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2001 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and local programs.

Supporting information

Crystal structure: contains datablocks 2, global. DOI: https://doi.org/10.1107/S160053680501264X/bt6656sup1.cif

Structure factors: contains datablock 2. DOI: https://doi.org/10.1107/S160053680501264X/bt66562sup2.hkl

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and local programs.

2-p-tolyl-5,6,7,8-tetrahydrobenzo[d]imidazo[2,1-b]thiazole top

Crystal data top

C₁₆H₁₆N₂S	F(000) = 568
M_r = 268.37	D_x = 1.318 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.1729 (4) Å	Cell parameters from 9390 reflections
b = 13.5386 (8) Å	θ = 2.1–28.5°
c = 14.3530 (8) Å	µ = 0.23 mm⁻¹
β = 103.917 (2)°	T = 160 K
V = 1352.92 (13) Å³	Block, colourless
Z = 4	0.44 × 0.30 × 0.26 mm

Data collection top

Bruker SMART 1K CCD diffractometer	3222 independent reflections
Radiation source: sealed tube	2871 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.022
Detector resolution: 8.192 pixels mm^-1	θ_max = 28.5°, θ_min = 2.1°
thin–slice ω scans	h = −9→9
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	k = −17→17
T_min = 0.91, T_max = 0.94	l = −18→18
11454 measured 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)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.103	H-atom parameters constrained
S = 1.05	w = 1/[σ²(F_o²) + (0.0542P)² + 0.5147P] where P = (F_o² + 2F_c²)/3
3222 reflections	(Δ/σ)_max < 0.001
192 parameters	Δρ_max = 0.32 e Å⁻³
36 restraints	Δρ_min = −0.25 e Å⁻³

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

	x	y	z	U_iso*/U_eq	Occ. (<1)
N1	0.58299 (16)	0.17620 (8)	0.14058 (8)	0.0257 (2)
N2	0.69620 (16)	0.02495 (8)	0.12171 (8)	0.0242 (2)
S1	0.35910 (5)	0.00517 (3)	0.14928 (3)	0.03065 (12)
C1	0.76869 (18)	0.18220 (10)	0.12686 (9)	0.0237 (3)
C2	0.54752 (18)	0.08082 (10)	0.13678 (9)	0.0242 (3)
C3	0.4914 (2)	−0.10047 (10)	0.13244 (9)	0.0268 (3)
C4	0.4184 (2)	−0.20417 (11)	0.13456 (11)	0.0326 (3)
H4A	0.3239	−0.2189	0.0736	0.039*	0.766 (6)
H4B	0.3535	−0.2114	0.1877	0.039*	0.766 (6)
H4X	0.2834	−0.2088	0.0971	0.039*	0.234 (6)
H4Y	0.4246	−0.2247	0.2014	0.039*	0.234 (6)
C5	0.5846 (3)	−0.27551 (14)	0.1484 (2)	0.0333 (6)	0.766 (6)
H5A	0.5345	−0.3435	0.1347	0.040*	0.766 (6)
H5B	0.6590	−0.2732	0.2161	0.040*	0.766 (6)
C6	0.7167 (4)	−0.25056 (15)	0.0826 (2)	0.0316 (6)	0.766 (6)
H6A	0.6409	−0.2503	0.0152	0.038*	0.766 (6)
H6B	0.8164	−0.3023	0.0890	0.038*	0.766 (6)
C5X	0.5584 (10)	−0.2755 (5)	0.0866 (7)	0.035 (2)	0.234 (6)
H5X1	0.5311	−0.3456	0.0980	0.042*	0.234 (6)
H5X2	0.5273	−0.2647	0.0163	0.042*	0.234 (6)
C6X	0.7701 (13)	−0.2555 (6)	0.1274 (8)	0.0367 (19)	0.234 (6)
H6X1	0.8478	−0.3011	0.0981	0.044*	0.234 (6)
H6X2	0.8033	−0.2670	0.1976	0.044*	0.234 (6)
C7	0.8147 (2)	−0.14939 (10)	0.10651 (11)	0.0304 (3)
H7A	0.9181	−0.1539	0.1661	0.036*	0.766 (6)
H7B	0.8721	−0.1278	0.0537	0.036*	0.766 (6)
H7X	0.9395	−0.1306	0.1494	0.036*	0.234 (6)
H7Y	0.8282	−0.1451	0.0396	0.036*	0.234 (6)
C8	0.66567 (19)	−0.07719 (9)	0.11945 (9)	0.0249 (3)
C9	0.84012 (19)	0.08993 (10)	0.11508 (10)	0.0258 (3)
H9	0.9626	0.0744	0.1046	0.031*
C10	0.86652 (18)	0.27755 (10)	0.12710 (9)	0.0241 (3)
C11	1.05548 (19)	0.28174 (10)	0.11660 (10)	0.0291 (3)
H11	1.1197	0.2224	0.1077	0.035*
C12	1.1500 (2)	0.37143 (11)	0.11911 (10)	0.0315 (3)
H12	1.2785	0.3722	0.1122	0.038*
C13	1.0616 (2)	0.46007 (10)	0.13146 (9)	0.0288 (3)
C14	0.8730 (2)	0.45609 (11)	0.14183 (10)	0.0317 (3)
H14	0.8092	0.5156	0.1507	0.038*
C15	0.7773 (2)	0.36671 (10)	0.13934 (10)	0.0294 (3)
H15	0.6487	0.3661	0.1461	0.035*
C16	1.1659 (2)	0.55676 (11)	0.13264 (11)	0.0360 (3)
H16A	1.3047	0.5455	0.1534	0.054*
H16B	1.1261	0.6024	0.1772	0.054*
H16C	1.1348	0.5854	0.0680	0.054*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0233 (5)	0.0267 (5)	0.0276 (5)	0.0019 (4)	0.0071 (4)	0.0006 (4)
N2	0.0238 (5)	0.0234 (5)	0.0262 (5)	0.0018 (4)	0.0080 (4)	0.0015 (4)
S1	0.02331 (18)	0.02947 (19)	0.0411 (2)	−0.00072 (12)	0.01156 (14)	0.00096 (14)
C1	0.0233 (6)	0.0262 (6)	0.0220 (6)	0.0019 (5)	0.0060 (5)	0.0012 (5)
C2	0.0214 (6)	0.0265 (6)	0.0253 (6)	0.0021 (5)	0.0069 (5)	0.0010 (5)
C3	0.0279 (6)	0.0256 (6)	0.0266 (6)	0.0007 (5)	0.0059 (5)	0.0017 (5)
C4	0.0337 (7)	0.0292 (7)	0.0348 (7)	−0.0068 (6)	0.0081 (6)	0.0019 (6)
C5	0.0387 (11)	0.0231 (9)	0.0372 (16)	−0.0024 (7)	0.0074 (9)	0.0046 (8)
C6	0.0373 (13)	0.0232 (9)	0.0350 (14)	0.0043 (8)	0.0098 (10)	−0.0003 (10)
C5X	0.039 (4)	0.026 (3)	0.037 (5)	0.000 (2)	0.005 (3)	0.003 (3)
C6X	0.042 (4)	0.031 (3)	0.032 (4)	0.000 (3)	0.000 (3)	−0.001 (3)
C7	0.0314 (7)	0.0255 (6)	0.0358 (7)	0.0029 (5)	0.0114 (6)	0.0013 (5)
C8	0.0285 (6)	0.0219 (6)	0.0244 (6)	0.0011 (5)	0.0064 (5)	0.0018 (5)
C9	0.0236 (6)	0.0249 (6)	0.0305 (6)	0.0013 (5)	0.0094 (5)	0.0019 (5)
C10	0.0250 (6)	0.0254 (6)	0.0215 (6)	0.0003 (5)	0.0048 (5)	0.0007 (5)
C11	0.0268 (7)	0.0293 (7)	0.0320 (7)	0.0014 (5)	0.0083 (5)	−0.0032 (5)
C12	0.0249 (6)	0.0383 (8)	0.0319 (7)	−0.0043 (5)	0.0079 (5)	−0.0028 (6)
C13	0.0323 (7)	0.0305 (7)	0.0219 (6)	−0.0070 (5)	0.0033 (5)	−0.0005 (5)
C14	0.0337 (7)	0.0254 (7)	0.0368 (7)	0.0010 (5)	0.0101 (6)	0.0012 (5)
C15	0.0261 (7)	0.0270 (6)	0.0366 (7)	0.0014 (5)	0.0101 (5)	0.0017 (5)
C16	0.0391 (8)	0.0340 (7)	0.0332 (7)	−0.0118 (6)	0.0053 (6)	−0.0003 (6)

Geometric parameters (Å, º) top

N1—C1	1.3949 (17)	C5X—C6X	1.515 (12)
N1—C2	1.3147 (17)	C6X—H6X1	0.990
N2—C2	1.3666 (16)	C6X—H6X2	0.990
N2—C8	1.3991 (16)	C6X—C7	1.518 (8)
N2—C9	1.3770 (17)	C7—H7A	0.990
S1—C2	1.7391 (13)	C7—H7B	0.990
S1—C3	1.7650 (14)	C7—H7X	0.990
C1—C9	1.3760 (18)	C7—H7Y	0.990
C1—C10	1.4689 (18)	C7—C8	1.4926 (18)
C3—C4	1.5014 (19)	C9—H9	0.950
C3—C8	1.3447 (19)	C10—C11	1.4005 (18)
C4—H4A	0.990	C10—C15	1.3971 (18)
C4—H4B	0.990	C11—H11	0.950
C4—H4X	0.990	C11—C12	1.387 (2)
C4—H4Y	0.990	C12—H12	0.950
C4—C5	1.510 (2)	C12—C13	1.389 (2)
C4—C5X	1.658 (7)	C13—C14	1.397 (2)
C5—H5A	0.990	C13—C16	1.5061 (19)
C5—H5B	0.990	C14—H14	0.950
C5—C6	1.528 (3)	C14—C15	1.388 (2)
C6—H6A	0.990	C15—H15	0.950
C6—H6B	0.990	C16—H16A	0.980
C6—C7	1.540 (3)	C16—H16B	0.980
C5X—H5X1	0.990	C16—H16C	0.980
C5X—H5X2	0.990

C1—N1—C2	103.49 (11)	C5X—C6X—C7	109.4 (7)
C2—N2—C8	115.28 (11)	H6X1—C6X—H6X2	108.2
C2—N2—C9	106.49 (11)	H6X1—C6X—C7	109.8
C8—N2—C9	138.21 (11)	H6X2—C6X—C7	109.8
C2—S1—C3	90.36 (6)	C6—C7—H7A	110.1
N1—C1—C9	111.16 (11)	C6—C7—H7B	110.1
N1—C1—C10	121.52 (11)	C6—C7—C8	107.94 (13)
C9—C1—C10	127.32 (12)	C6X—C7—H7X	108.8
N1—C2—N2	113.56 (11)	C6X—C7—H7Y	108.8
N1—C2—S1	136.19 (10)	C6X—C7—C8	113.9 (3)
N2—C2—S1	110.23 (10)	H7A—C7—H7B	108.4
S1—C3—C4	123.59 (10)	H7A—C7—C8	110.1
S1—C3—C8	112.18 (10)	H7B—C7—C8	110.1
C4—C3—C8	124.22 (13)	H7X—C7—H7Y	107.7
C3—C4—H4A	109.8	H7X—C7—C8	108.8
C3—C4—H4B	109.8	H7Y—C7—C8	108.8
C3—C4—H4X	110.4	N2—C8—C3	111.96 (11)
C3—C4—H4Y	110.4	N2—C8—C7	122.51 (11)
C3—C4—C5	109.43 (13)	C3—C8—C7	125.52 (12)
C3—C4—C5X	106.7 (2)	N2—C9—C1	105.31 (11)
H4A—C4—H4B	108.2	N2—C9—H9	127.3
H4A—C4—C5	109.8	C1—C9—H9	127.3
H4B—C4—C5	109.8	C1—C10—C11	120.64 (12)
H4X—C4—H4Y	108.6	C1—C10—C15	121.77 (12)
H4X—C4—C5X	110.4	C11—C10—C15	117.59 (12)
H4Y—C4—C5X	110.4	C10—C11—H11	119.6
C4—C5—H5A	109.4	C10—C11—C12	120.84 (13)
C4—C5—H5B	109.4	H11—C11—C12	119.6
C4—C5—C6	111.4 (2)	C11—C12—H12	119.2
H5A—C5—H5B	108.0	C11—C12—C13	121.61 (13)
H5A—C5—C6	109.4	H12—C12—C13	119.2
H5B—C5—C6	109.4	C12—C13—C14	117.66 (13)
C5—C6—H6A	109.2	C12—C13—C16	120.75 (14)
C5—C6—H6B	109.2	C14—C13—C16	121.58 (14)
C5—C6—C7	112.1 (2)	C13—C14—H14	119.4
H6A—C6—H6B	107.9	C13—C14—C15	121.12 (13)
H6A—C6—C7	109.2	H14—C14—C15	119.4
H6B—C6—C7	109.2	C10—C15—C14	121.18 (13)
C4—C5X—H5X1	109.0	C10—C15—H15	119.4
C4—C5X—H5X2	109.0	C14—C15—H15	119.4
C4—C5X—C6X	112.7 (6)	C13—C16—H16A	109.5
H5X1—C5X—H5X2	107.8	C13—C16—H16B	109.5
H5X1—C5X—C6X	109.0	C13—C16—H16C	109.5
H5X2—C5X—C6X	109.0	H16A—C16—H16B	109.5
C5X—C6X—H6X1	109.8	H16A—C16—H16C	109.5
C5X—C6X—H6X2	109.8	H16B—C16—H16C	109.5

C2—N1—C1—C9	0.04 (14)	C2—N2—C8—C3	0.29 (16)
C2—N1—C1—C10	−179.28 (11)	C2—N2—C8—C7	−178.23 (12)
C1—N1—C2—N2	0.03 (14)	C9—N2—C8—C3	178.36 (15)
C1—N1—C2—S1	177.90 (12)	C9—N2—C8—C7	−0.2 (2)
C8—N2—C2—N1	178.58 (11)	C6—C7—C8—N2	−166.19 (16)
C8—N2—C2—S1	0.15 (14)	C6—C7—C8—C3	15.5 (2)
C9—N2—C2—N1	−0.08 (15)	C6X—C7—C8—N2	167.5 (5)
C9—N2—C2—S1	−178.51 (9)	C6X—C7—C8—C3	−10.8 (5)
C3—S1—C2—N1	−178.32 (15)	N1—C1—C9—N2	−0.08 (15)
C3—S1—C2—N2	−0.39 (10)	C10—C1—C9—N2	179.18 (12)
C2—S1—C3—C4	179.36 (12)	C2—N2—C9—C1	0.10 (14)
C2—S1—C3—C8	0.57 (11)	C8—N2—C9—C1	−178.09 (14)
S1—C3—C4—C5	−162.66 (15)	N1—C1—C10—C11	177.71 (12)
S1—C3—C4—C5X	164.7 (3)	N1—C1—C10—C15	−1.16 (19)
C8—C3—C4—C5	16.0 (2)	C9—C1—C10—C11	−1.5 (2)
C8—C3—C4—C5X	−16.7 (4)	C9—C1—C10—C15	179.65 (13)
C3—C4—C5—C6	−45.8 (3)	C1—C10—C11—C12	−178.43 (12)
C4—C5—C6—C7	64.3 (3)	C15—C10—C11—C12	0.5 (2)
C3—C4—C5X—C6X	47.9 (8)	C10—C11—C12—C13	−0.4 (2)
C4—C5X—C6X—C7	−61.1 (10)	C11—C12—C13—C14	0.3 (2)
C5X—C6X—C7—C8	41.1 (9)	C11—C12—C13—C16	−179.17 (13)
C5—C6—C7—C8	−45.5 (3)	C12—C13—C14—C15	−0.3 (2)
S1—C3—C8—N2	−0.59 (14)	C16—C13—C14—C15	179.12 (13)
S1—C3—C8—C7	177.88 (11)	C13—C14—C15—C10	0.5 (2)
C4—C3—C8—N2	−179.37 (12)	C1—C10—C15—C14	178.36 (13)
C4—C3—C8—C7	−0.9 (2)	C11—C10—C15—C14	−0.5 (2)

Acknowledgements

We thank the EPSRC for financial support and Dr Ian Hardcastle for supplying the sample.

References

Allen, F. H. (2002). Acta Cryst. B58, 380–388. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Bruker (2001). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Komarov, P. G., Komarova, E. A., Kondratov, R. V, Christov-Tselkov, K., Coon, J. S., Chernov, M. V. & Gudkov, A. V. (1999). Science, 285, 1733–1737. Web of Science CrossRef PubMed CAS Google Scholar
Sheldrick, G. M. (2001). SHELXTL. Version 6. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Sheldrick, G. M. (2003). SADABS. University of Göttingen, Germany. Google Scholar
Walton, M. I., Wilson, S. C., Hardcastle, I. R., Mirza, A. R. & Workman, P. (2005). Mol. Cancer Ther. In the press. Google Scholar

© International Union of Crystallography. Prior permission is not required to reproduce short quotations, tables and figures from this article, provided the original authors and source are cited. For more information, click here.

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 61| Part 5| May 2005| Pages o1486-o1488

https://doi.org/10.1107/S160053680501264X

Format		BIBTeX
		EndNote
		RefMan
		Refer
		Medline
		CIF
		SGML
		Plain Text

Format		BIBTeX
		EndNote
		RefMan
		Refer
		Medline
		CIF
		SGML
		Plain Text

Search IUCr Journals		doi		Advanced search
Author		volume	page

organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Pifithrin-β

Comment

Experimental

Crystal data

Data collection

Refinement

Supporting information

Acknowledgements

References

organic compounds