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Acta Cryst. (2008). E64, o1876    [ doi:10.1107/S1600536808027712 ]

Triphenyl(3,4,5-trimethoxybenzyl)phosphonium chloride monohydrate

A. M. Barkell, J. Sharp and S. J. Simpson

Abstract top

The asymmetric unit of the title salt, C28H28O3P+·Cl-·H2O, contains a benzyltriphenylphosphonium cation, a chloride counter-ion, and a water molecule of crystallization. The 3,4,5-trimethoxy substituents of the benzylic functionality are arranged with the 3,5-methyl groups lying approximately in the aromatic ring plane while the 4-methyl group is out of the plane.

Comment top

The 3,4,5-trimethoxyphenyl group is found in a number of natural products with antifungal properties such as Brittonin A and B (Asakawa et al., 1976), and central nervous system therapeutic properties such as Kadsurin (Mervič et al., 1977). A number of anticancer chalcones also contain this functionality (Lawrence et al., 2006); common synthetic routes to these products involve Wittig chemistry or Knoevenagel condensation reactions. The title compound is a Wittig precursor requiring deprotonation in the presence of a carbonyl compound.

The activity of the molecule classes above is believed to be related to the conformation of the 3,4,5-trimethoxyphenyl group relative to the other aromatic ring present. One aspect of this may be due to the disposition of the three methoxy groups, and the title molecule was chosen to provide a simple starting reference point for a more extensive study.

The structure obtained shows that O—C vectors are directed at 7, 81, and 8° to the phenyl ring plane for the 3,4, and 5-methoxy groups respectively.

Related literature top

For background, see: Asakawa et al. (1976); Mervič et al. (1977); Lawrence et al. (2006).

Experimental top

The title compound was obtained from 3,4,5-trimethoxybenzyl alcohol in two steps.

The alcohol (20 g, 0.1 mol) was dissolved in diethylether (200 ml) and cooled to 0°C. Thionyl chloride (15 ml, 0.21 mol) was added dropwise over thirty minutes and the solution was stirred for two hours. Water (120 ml) was added portionwise and the ether layer was separated. Extraction of the aqueous layer with diethylether (3 x 25 ml), combination of the ether fractions, drying over granular calcium chloride, and removal of the solvent under reduced pressure gave white microcrystalline 3,4,5-trimethoxybenzyl chloride in near quantitative yield.

The product from the first stage was mixed with triphenylphosphine (37.2 g, 0.115 mol). Addition of toluene (200 ml) and pump-purging with nitrogen gave a colourless solution which was heated under nitrogen at reflux temperature for thirty hours. The reaction mixture was allowed to cool to room temperature before being filtered under nitrogen. The white microcrystalline product was washed with petroleum ether and dried under reduced pressure (42.1 g, 72%).

Crystallization of a small sample by layering petroleum ether (40–60°C) onto a concentrated dichloromethane solution produced crystals suitable for the structure determination.

Refinement top

H atoms bonded to the O atom were located in a difference map and refined with distance restraints of O—H = 0.84 Å, and with Uiso(H) = 1.2Ueq(O). Other H atoms were positioned geometrically and refined using a riding model, with C—H = 0.93–0.96 Å and with Uiso(H) = 1.2 (1.5 for methyl groups) times Ueq(C).

Computing details top

Data collection: XSCANS (Bruker, 1997); cell refinement: XSCANS (Bruker, 1997); data reduction: XSCANS (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the salt, with atom labels and 25% probability displacement ellipsoids for non-H atoms.
Triphenyl(3,4,5-trimethoxybenzyl)phosphonium chloride monohydrate top
Crystal data top
C28H28O3P+·Cl−·H2OZ = 2
Mr = 496.94F(000) = 524
Triclinic, P1Dx = 1.234 Mg m−3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 10.5818 (8) ÅCell parameters from 40 reflections
b = 10.6160 (15) Åθ = 9.0–12.5°
c = 13.8876 (15) ŵ = 0.23 mm−1
α = 111.020 (9)°T = 294 K
β = 95.895 (7)°Block, colourless
γ = 108.697 (11)°0.35 × 0.30 × 0.25 mm
V = 1337.0 (3) Å3
Data collection top
Bruker P4
diffractometer		Rint = 0.013
Radiation source: fine-focus sealed tube, Bruker P4θmax = 27.5°, θmin = 1.8°
graphiteh = −13→1
ω scansk = −12→12
6874 measured reflectionsl = −18→18
5905 independent reflections3 standard reflections every 147 reflections
4821 reflections with I > 2σ(I) intensity decay: 0.5%
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.041Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.112H atoms treated by a mixture of independent and constrained refinement
S = 1.03 w = 1/[σ2(Fo2) + (0.0485P)2 + 0.4603P]
where P = (Fo2 + 2Fc2)/3
5905 reflections(Δ/σ)max < 0.001
313 parametersΔρmax = 0.31 e Å−3
0 restraintsΔρmin = −0.33 e Å−3
0 constraints
Crystal data top
C28H28O3P+·Cl−·H2Oγ = 108.697 (11)°
Mr = 496.94V = 1337.0 (3) Å3
Triclinic, P1Z = 2
a = 10.5818 (8) ÅMo Kα radiation
b = 10.6160 (15) ŵ = 0.23 mm−1
c = 13.8876 (15) ÅT = 294 K
α = 111.020 (9)°0.35 × 0.30 × 0.25 mm
β = 95.895 (7)°
Data collection top
Bruker P4
diffractometer		Rint = 0.013
6874 measured reflectionsθmax = 27.5°
5905 independent reflections3 standard reflections every 147 reflections
4821 reflections with I > 2σ(I) intensity decay: 0.5%
Refinement top
R[F2 > 2σ(F2)] = 0.041H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.112Δρmax = 0.31 e Å−3
S = 1.03Δρmin = −0.33 e Å−3
5905 reflectionsAbsolute structure: ?
313 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
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
xyzUiso*/Ueq
C10.59549 (16)0.30260 (16)0.18593 (12)0.0346 (3)
C20.73649 (16)0.35116 (17)0.19652 (12)0.0369 (3)
H2A0.77800.28420.17410.044*
C30.81545 (16)0.49986 (17)0.24067 (12)0.0373 (3)
C40.75394 (17)0.60102 (16)0.27451 (12)0.0376 (3)
C50.61208 (17)0.55084 (17)0.26445 (13)0.0380 (3)
C60.53270 (16)0.40187 (17)0.21970 (13)0.0386 (3)
H6A0.43800.36880.21240.046*
C70.51360 (16)0.13991 (16)0.13848 (12)0.0366 (3)
H7A0.56830.09070.10090.055*
H7B0.43190.11740.08660.055*
P10.46139 (4)0.06666 (4)0.23356 (3)0.03399 (11)
C120.2474 (2)−0.2060 (2)0.15299 (17)0.0580 (5)
H12A0.1956−0.15790.18900.070*
C130.1887 (3)−0.3548 (2)0.0915 (2)0.0779 (8)
H13A0.0966−0.40650.08530.093*
C140.2640 (3)−0.4265 (2)0.03979 (18)0.0780 (8)
H14A0.2236−0.5270−0.00060.094*
C150.4004 (3)−0.3509 (2)0.04689 (17)0.0708 (7)
H15A0.4515−0.40090.01160.085*
C160.4617 (2)−0.2005 (2)0.10669 (15)0.0525 (4)
H16A0.5529−0.14900.11030.063*
C110.38491 (18)−0.12838 (17)0.16085 (13)0.0415 (4)
C220.68223 (19)0.26808 (19)0.40368 (14)0.0486 (4)
H22A0.65780.33860.39130.058*
C230.7940 (2)0.3093 (2)0.48553 (16)0.0608 (5)
H23A0.84450.40810.52790.073*
C240.8313 (2)0.2062 (3)0.50507 (17)0.0655 (6)
H24A0.90640.23510.56040.079*
C250.7571 (2)0.0608 (3)0.44254 (18)0.0672 (6)
H25A0.7821−0.00900.45560.081*
C260.6446 (2)0.0167 (2)0.35967 (16)0.0529 (4)
H26A0.5950−0.08240.31750.064*
C210.60641 (16)0.11974 (18)0.33980 (13)0.0384 (3)
C320.3431 (2)0.1799 (2)0.39684 (15)0.0560 (5)
H32A0.41500.18230.44290.067*
C330.2424 (3)0.2246 (3)0.43595 (17)0.0705 (6)
H33A0.24670.25700.50840.085*
C340.1362 (2)0.2213 (3)0.36822 (18)0.0630 (5)
H34A0.06960.25280.39520.076*
C350.12752 (19)0.1718 (2)0.26053 (16)0.0537 (5)
H35A0.05440.16820.21490.064*
C360.22765 (18)0.12755 (19)0.22064 (14)0.0449 (4)
H36A0.22250.09500.14810.054*
C310.33660 (16)0.13157 (17)0.28894 (13)0.0381 (3)
O10.95480 (12)0.55746 (13)0.25460 (11)0.0512 (3)
O20.83251 (14)0.74874 (12)0.32194 (10)0.0508 (3)
O30.56099 (14)0.65759 (14)0.30251 (12)0.0531 (3)
C501.0203 (2)0.4558 (2)0.2316 (2)0.0654 (6)
H50A1.11760.50710.24440.098*
H50B0.98390.38720.15830.098*
H50C1.00360.40440.27640.098*
C600.8700 (3)0.8112 (2)0.2485 (2)0.0795 (8)
H60A0.92400.91400.28690.119*
H60B0.78830.79680.20170.119*
H60C0.92290.76480.20750.119*
C700.4212 (2)0.6117 (2)0.3081 (2)0.0636 (6)
H70A0.39700.69550.33490.095*
H70B0.40900.56300.35480.095*
H70C0.36310.54580.23830.095*
Cl10.79294 (5)0.01474 (6)0.06989 (4)0.05847 (15)
O991.0516 (3)0.2095 (2)−0.0017 (2)0.1006 (7)
H99A1.095 (5)0.153 (5)−0.021 (3)0.151*
H99B0.982 (5)0.154 (5)0.016 (3)0.151*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0353 (8)0.0333 (7)0.0341 (7)0.0111 (6)0.0093 (6)0.0143 (6)
C20.0343 (8)0.0346 (8)0.0399 (8)0.0135 (6)0.0105 (6)0.0126 (6)
C30.0311 (7)0.0384 (8)0.0379 (8)0.0099 (6)0.0087 (6)0.0138 (6)
C40.0400 (8)0.0300 (7)0.0375 (8)0.0090 (6)0.0110 (6)0.0116 (6)
C50.0409 (8)0.0366 (8)0.0415 (8)0.0183 (7)0.0133 (7)0.0180 (7)
C60.0329 (8)0.0390 (8)0.0449 (9)0.0132 (6)0.0105 (6)0.0187 (7)
C70.0346 (8)0.0342 (8)0.0361 (8)0.0100 (6)0.0093 (6)0.0118 (6)
P10.03064 (19)0.03014 (19)0.0356 (2)0.00880 (15)0.00623 (15)0.01065 (15)
C120.0451 (10)0.0435 (10)0.0684 (13)0.0021 (8)0.0025 (9)0.0208 (9)
C130.0682 (15)0.0455 (12)0.0816 (16)−0.0120 (11)−0.0115 (13)0.0226 (12)
C140.112 (2)0.0323 (10)0.0544 (12)0.0001 (12)−0.0074 (13)0.0113 (9)
C150.122 (2)0.0448 (11)0.0487 (11)0.0387 (13)0.0235 (12)0.0161 (9)
C160.0687 (12)0.0404 (9)0.0480 (10)0.0202 (9)0.0172 (9)0.0178 (8)
C110.0442 (9)0.0326 (8)0.0392 (8)0.0080 (7)0.0036 (7)0.0133 (6)
C220.0499 (10)0.0407 (9)0.0444 (9)0.0121 (8)0.0030 (8)0.0130 (7)
C230.0533 (11)0.0555 (11)0.0454 (10)0.0058 (9)−0.0045 (9)0.0080 (9)
C240.0510 (11)0.0850 (16)0.0502 (11)0.0270 (11)−0.0031 (9)0.0202 (11)
C250.0725 (14)0.0727 (14)0.0609 (13)0.0404 (12)0.0008 (11)0.0259 (11)
C260.0563 (11)0.0456 (10)0.0520 (10)0.0211 (9)0.0019 (8)0.0168 (8)
C210.0344 (8)0.0380 (8)0.0376 (8)0.0118 (6)0.0061 (6)0.0128 (6)
C320.0555 (11)0.0788 (14)0.0410 (9)0.0340 (10)0.0164 (8)0.0246 (9)
C330.0757 (15)0.0980 (18)0.0470 (11)0.0454 (14)0.0307 (11)0.0256 (11)
C340.0559 (12)0.0736 (14)0.0702 (13)0.0359 (11)0.0319 (11)0.0273 (11)
C350.0397 (9)0.0608 (11)0.0604 (11)0.0224 (9)0.0116 (8)0.0226 (9)
C360.0405 (9)0.0494 (10)0.0404 (9)0.0172 (8)0.0083 (7)0.0143 (7)
C310.0352 (8)0.0386 (8)0.0375 (8)0.0122 (6)0.0113 (6)0.0139 (6)
O10.0307 (6)0.0434 (7)0.0654 (8)0.0083 (5)0.0126 (5)0.0122 (6)
O20.0550 (7)0.0310 (6)0.0530 (7)0.0068 (5)0.0177 (6)0.0102 (5)
O30.0512 (7)0.0418 (7)0.0751 (9)0.0260 (6)0.0240 (7)0.0242 (6)
C500.0370 (10)0.0626 (13)0.0881 (16)0.0218 (9)0.0163 (10)0.0193 (11)
C600.104 (2)0.0470 (12)0.0939 (18)0.0200 (12)0.0490 (16)0.0374 (12)
C700.0555 (12)0.0657 (13)0.0885 (16)0.0382 (10)0.0347 (11)0.0349 (12)
Cl10.0422 (2)0.0691 (3)0.0547 (3)0.0258 (2)0.00903 (19)0.0125 (2)
O990.1220 (19)0.0785 (13)0.1320 (18)0.0569 (13)0.0683 (15)0.0509 (13)
Geometric parameters (Å, °) top
C1—C21.386 (2)C23—H23A0.9300
C1—C61.389 (2)C24—C251.369 (3)
C1—C71.508 (2)C24—H24A0.9300
C2—C31.386 (2)C25—C261.391 (3)
C2—H2A0.9300C25—H25A0.9300
C3—O11.3654 (19)C26—C211.384 (3)
C3—C41.395 (2)C26—H26A0.9300
C4—O21.3766 (19)C32—C331.384 (3)
C4—C51.396 (2)C32—C311.385 (2)
C5—O31.3704 (19)C32—H32A0.9300
C5—C61.389 (2)C33—C341.372 (3)
C6—H6A0.9300C33—H33A0.9300
C7—P11.8069 (16)C34—C351.378 (3)
C7—H7A0.9700C34—H34A0.9300
C7—H7B0.9700C35—C361.379 (3)
P1—C111.7943 (17)C35—H35A0.9300
P1—C311.7949 (17)C36—C311.395 (2)
P1—C211.7982 (16)C36—H36A0.9300
C12—C131.380 (3)O1—C501.423 (2)
C12—C111.393 (3)O2—C601.427 (3)
C12—H12A0.9300O3—C701.421 (2)
C13—C141.358 (4)C50—H50A0.9600
C13—H13A0.9300C50—H50B0.9600
C14—C151.381 (4)C50—H50C0.9600
C14—H14A0.9300C60—H60A0.9600
C15—C161.391 (3)C60—H60B0.9600
C15—H15A0.9300C60—H60C0.9600
C16—C111.387 (3)C70—H70A0.9600
C16—H16A0.9300C70—H70B0.9600
C22—C231.385 (3)C70—H70C0.9600
C22—C211.397 (2)O99—H99A0.85 (4)
C22—H22A0.9300O99—H99B0.89 (4)
C23—C241.377 (3)
C2—C1—C6120.50 (14)C22—C23—H23A119.5
C2—C1—C7118.08 (14)C25—C24—C23119.54 (19)
C6—C1—C7121.41 (14)C25—C24—H24A120.2
C3—C2—C1119.79 (15)C23—C24—H24A120.2
C3—C2—H2A120.1C24—C25—C26120.6 (2)
C1—C2—H2A120.1C24—C25—H25A119.7
O1—C3—C2123.80 (15)C26—C25—H25A119.7
O1—C3—C4115.76 (14)C21—C26—C25120.13 (18)
C2—C3—C4120.44 (14)C21—C26—H26A119.9
O2—C4—C3120.66 (15)C25—C26—H26A119.9
O2—C4—C5120.02 (15)C26—C21—C22119.22 (16)
C3—C4—C5119.26 (14)C26—C21—P1121.36 (13)
O3—C5—C6124.28 (15)C22—C21—P1119.41 (13)
O3—C5—C4115.34 (14)C33—C32—C31119.84 (19)
C6—C5—C4120.37 (15)C33—C32—H32A120.1
C5—C6—C1119.63 (15)C31—C32—H32A120.1
C5—C6—H6A120.2C34—C33—C32120.24 (19)
C1—C6—H6A120.2C34—C33—H33A119.9
C1—C7—P1114.83 (11)C32—C33—H33A119.9
C1—C7—H7A108.6C33—C34—C35120.53 (19)
P1—C7—H7A108.6C33—C34—H34A119.7
C1—C7—H7B108.6C35—C34—H34A119.7
P1—C7—H7B108.6C34—C35—C36119.77 (18)
H7A—C7—H7B107.5C34—C35—H35A120.1
C11—P1—C31109.68 (8)C36—C35—H35A120.1
C11—P1—C21110.92 (8)C35—C36—C31120.13 (16)
C31—P1—C21108.89 (8)C35—C36—H36A119.9
C11—P1—C7106.24 (7)C31—C36—H36A119.9
C31—P1—C7110.07 (8)C32—C31—C36119.49 (16)
C21—P1—C7111.01 (8)C32—C31—P1121.59 (14)
C13—C12—C11119.6 (2)C36—C31—P1118.87 (12)
C13—C12—H12A120.2C3—O1—C50116.07 (14)
C11—C12—H12A120.2C4—O2—C60114.00 (15)
C14—C13—C12120.6 (2)C5—O3—C70117.11 (14)
C14—C13—H13A119.7O1—C50—H50A109.5
C12—C13—H13A119.7O1—C50—H50B109.5
C13—C14—C15120.4 (2)H50A—C50—H50B109.5
C13—C14—H14A119.8O1—C50—H50C109.5
C15—C14—H14A119.8H50A—C50—H50C109.5
C14—C15—C16120.3 (2)H50B—C50—H50C109.5
C14—C15—H15A119.9O2—C60—H60A109.5
C16—C15—H15A119.9O2—C60—H60B109.5
C11—C16—C15119.1 (2)H60A—C60—H60B109.5
C11—C16—H16A120.5O2—C60—H60C109.5
C15—C16—H16A120.5H60A—C60—H60C109.5
C16—C11—C12120.02 (17)H60B—C60—H60C109.5
C16—C11—P1119.19 (14)O3—C70—H70A109.5
C12—C11—P1120.66 (15)O3—C70—H70B109.5
C23—C22—C21119.55 (18)H70A—C70—H70B109.5
C23—C22—H22A120.2O3—C70—H70C109.5
C21—C22—H22A120.2H70A—C70—H70C109.5
C24—C23—C22120.96 (19)H70B—C70—H70C109.5
C24—C23—H23A119.5H99A—O99—H99B100 (4)
C6—C1—C2—C3−0.3 (2)C21—C22—C23—C24−0.1 (3)
C7—C1—C2—C3−179.41 (14)C22—C23—C24—C250.1 (4)
C1—C2—C3—O1179.69 (15)C23—C24—C25—C260.0 (4)
C1—C2—C3—C40.0 (2)C24—C25—C26—C21−0.2 (4)
O1—C3—C4—O2−2.1 (2)C25—C26—C21—C220.2 (3)
C2—C3—C4—O2177.63 (14)C25—C26—C21—P1−179.85 (17)
O1—C3—C4—C5−179.06 (15)C23—C22—C21—C260.0 (3)
C2—C3—C4—C50.7 (2)C23—C22—C21—P1−179.99 (16)
O2—C4—C5—O31.2 (2)C11—P1—C21—C26−1.85 (18)
C3—C4—C5—O3178.17 (14)C31—P1—C21—C26118.94 (16)
O2—C4—C5—C6−178.00 (14)C7—P1—C21—C26−119.73 (16)
C3—C4—C5—C6−1.0 (2)C11—P1—C21—C22178.12 (14)
O3—C5—C6—C1−178.40 (15)C31—P1—C21—C22−61.09 (16)
C4—C5—C6—C10.7 (2)C7—P1—C21—C2260.24 (16)
C2—C1—C6—C50.0 (2)C31—C32—C33—C340.0 (4)
C7—C1—C6—C5179.03 (14)C32—C33—C34—C350.9 (4)
C2—C1—C7—P1103.56 (15)C33—C34—C35—C36−1.2 (3)
C6—C1—C7—P1−75.54 (17)C34—C35—C36—C310.6 (3)
C1—C7—P1—C11−173.31 (12)C33—C32—C31—C36−0.5 (3)
C1—C7—P1—C3168.01 (13)C33—C32—C31—P1−177.89 (18)
C1—C7—P1—C21−52.62 (14)C35—C36—C31—C320.2 (3)
C11—C12—C13—C140.9 (4)C35—C36—C31—P1177.66 (14)
C12—C13—C14—C15−0.9 (4)C11—P1—C31—C32107.02 (17)
C13—C14—C15—C16−0.3 (4)C21—P1—C31—C32−14.53 (18)
C14—C15—C16—C111.5 (3)C7—P1—C31—C32−136.43 (16)
C15—C16—C11—C12−1.4 (3)C11—P1—C31—C36−70.42 (15)
C15—C16—C11—P1−177.44 (15)C21—P1—C31—C36168.03 (13)
C13—C12—C11—C160.3 (3)C7—P1—C31—C3646.13 (15)
C13—C12—C11—P1176.19 (17)C2—C3—O1—C50−6.6 (3)
C31—P1—C11—C16176.66 (14)C4—C3—O1—C50173.14 (17)
C21—P1—C11—C16−63.01 (16)C3—C4—O2—C6081.1 (2)
C7—P1—C11—C1657.73 (16)C5—C4—O2—C60−102.0 (2)
C31—P1—C11—C120.69 (18)C6—C5—O3—C708.1 (3)
C21—P1—C11—C12121.01 (16)C4—C5—O3—C70−171.10 (17)
C7—P1—C11—C12−118.25 (16)
Acknowledgements top

We thank Dr N. M. Boag (Salford University) for access to the diffractometer.

references
References top

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