Felbamate: a carbamate-type anticonvulsant

In the crystal structure of 2-phen­yl-1,3-propane­diol dicarb­amate (felbamate), C₁₁H₁₄N₂O₄, the mol­ecule is in an extended conformation with respect to the phen­yl ring. In the crystal structure, the mol­ecules are connected via N—H...O hydrogen bonds to form one-dimensional ribbons running along the b axis. Stereochemical and mol­ecular modelling results indicate that the mechanism of the anti­convulsant action of felbamate is likely to differ from that of classical anticonvulsants.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.034
• wR factor = 0.093
• Data-to-parameter ratio = 9.2

checkCIF/PLATON results

No syntax errors found





Alert level A
PLAT027_ALERT_3_A _diffrn_reflns_theta_full (too) Low ............      64.98 Deg.

Author Response: ...'see _exptl_special_details'

Alert level C
REFNR01_ALERT_3_C  Ratio of reflections to parameters is < 10 for a
            centrosymmetric structure
            sine(theta)/lambda                0.5877
            Proportion of unique data used    1.0000
            Ratio reflections to parameters   9.1943
THETM01_ALERT_3_C  The value of sine(theta_max)/wavelength is less than 0.590
            Calculated sin(theta_max)/wavelength =    0.5877
PLAT023_ALERT_3_C Resolution (too) Low [sin(th)/Lambda < 0.6].....      64.98 Deg.
PLAT088_ALERT_3_C Poor Data / Parameter Ratio ....................       9.19

   1 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   5 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: Picker Operating Manual (Picker, 1967); cell refinement: Picker Operating Manual; data reduction: Picker Operating Manual; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

2-Phenyl-1,3-propanediol dicarbamate

Crystal data

C11H14N2O4	F(000) = 504
Mr = 238.24	Dx = 1.383 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54178 Å
a = 8.394 (3) Å	Cell parameters from 16 reflections
b = 5.158 (2) Å	θ = 20–48°
c = 26.972 (6) Å	µ = 0.90 mm^−1
β = 101.47 (2)°	T = 294 K
V = 1144.5 (7) Å^3	Transparent needle, colourless
Z = 4	0.45 × 0.15 × 0.10 mm

Data collection

Picker FACS-1 four-circle diffractometer	Rint = 0.000
Radiation source: fine-focus sealed tube	θmax = 65.0°, θmin = 3.3°
Ni-filtered radiation monochromator	h = 0→9
θ/2θ scans	k = 0→6
1940 measured reflections	l = −31→30
1940 independent reflections	3 standard reflections every 100 reflections
1634 reflections with I > 2σ(I)	intensity decay: 0.5%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.034	All H-atom parameters refined
wR(F^2) = 0.093	w = 1/[σ^2(Fo^2) + (0.0278P)^2 + 0.2981P] where P = (Fo^2 + 2Fc^2)/3
S = 1.01	(Δ/σ)max < 0.001
1940 reflections	Δρmax = 0.16 e Å^−3
211 parameters	Δρmin = −0.16 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0079 (6)

Special details

Experimental. There were no observable reflections above θ = 55°, only the background noise. The intensity data were collected on a crystal with dimensions 0.50 x 0.20 x. 22 mm mounted along its long axis.

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 (Ų)

	x	y	z	Uiso*/Ueq
C1	−0.11608 (19)	0.1854 (3)	0.32097 (6)	0.0378 (4)
C2	−0.1475 (2)	0.1293 (4)	0.26964 (6)	0.0462 (4)
C3	−0.2603 (2)	0.2703 (4)	0.23595 (7)	0.0531 (5)
C4	−0.3435 (2)	0.4700 (4)	0.25291 (8)	0.0551 (5)
C5	−0.3146 (3)	0.5273 (4)	0.30361 (8)	0.0606 (5)
C6	−0.2019 (2)	0.3868 (4)	0.33749 (7)	0.0535 (5)
C7	0.00891 (19)	0.0282 (3)	0.35710 (6)	0.0364 (4)
C8	−0.0523 (2)	−0.0297 (3)	0.40542 (6)	0.0403 (4)
C9	0.17351 (19)	0.1650 (3)	0.36608 (6)	0.0392 (4)
C10	0.15216 (19)	−0.1731 (3)	0.47427 (5)	0.0347 (4)
C11	0.43606 (18)	0.0546 (3)	0.41442 (6)	0.0364 (4)
N1	0.2222 (2)	−0.3802 (3)	0.49863 (6)	0.0485 (4)
N2	0.52996 (18)	−0.1472 (3)	0.43143 (6)	0.0494 (4)
O1	0.03725 (13)	−0.2389 (2)	0.43411 (4)	0.0400 (3)
O2	0.18685 (14)	0.05035 (19)	0.48699 (4)	0.0412 (3)
O3	0.29471 (13)	−0.0264 (2)	0.38596 (4)	0.0388 (3)
O4	0.47217 (15)	0.2810 (2)	0.42249 (5)	0.0510 (3)
H2	−0.086 (2)	−0.017 (4)	0.2577 (7)	0.058 (6)*
H3	−0.283 (3)	0.227 (4)	0.2008 (8)	0.067 (6)*
H4	−0.419 (3)	0.573 (4)	0.2303 (8)	0.062 (6)*
H5	−0.375 (3)	0.666 (5)	0.3160 (8)	0.072 (6)*
H6	−0.186 (2)	0.423 (4)	0.3739 (8)	0.063 (6)*
H7	0.0218 (18)	−0.137 (3)	0.3420 (6)	0.032 (4)*
H11	0.196 (2)	−0.536 (4)	0.4873 (7)	0.054 (6)*
H12	0.313 (3)	−0.355 (4)	0.5233 (8)	0.061 (6)*
H21	0.617 (3)	−0.117 (4)	0.4563 (8)	0.064 (6)*
H22	0.489 (3)	−0.305 (5)	0.4258 (8)	0.060 (6)*
H81	−0.0445 (19)	0.120 (3)	0.4271 (6)	0.032 (4)*
H82	−0.163 (2)	−0.100 (4)	0.3973 (6)	0.044 (5)*
H91	0.177 (2)	0.313 (4)	0.3902 (7)	0.046 (5)*
H92	0.194 (2)	0.232 (3)	0.3328 (7)	0.046 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0350 (8)	0.0348 (8)	0.0401 (8)	−0.0037 (6)	−0.0010 (6)	0.0027 (7)
C2	0.0427 (9)	0.0544 (11)	0.0400 (9)	0.0039 (8)	0.0045 (7)	0.0062 (8)
C3	0.0477 (10)	0.0675 (13)	0.0404 (10)	−0.0016 (9)	0.0002 (8)	0.0140 (9)
C4	0.0452 (10)	0.0507 (11)	0.0618 (12)	0.0001 (9)	−0.0081 (9)	0.0183 (9)
C5	0.0575 (12)	0.0438 (10)	0.0720 (13)	0.0136 (9)	−0.0077 (10)	−0.0009 (9)
C6	0.0577 (11)	0.0442 (10)	0.0509 (10)	0.0091 (9)	−0.0079 (8)	−0.0054 (8)
C7	0.0371 (8)	0.0330 (8)	0.0358 (8)	0.0014 (6)	−0.0005 (6)	−0.0020 (6)
C8	0.0392 (9)	0.0391 (9)	0.0402 (9)	0.0008 (7)	0.0022 (7)	0.0032 (7)
C9	0.0380 (9)	0.0345 (8)	0.0417 (9)	0.0035 (7)	0.0001 (7)	0.0036 (7)
C10	0.0405 (8)	0.0298 (8)	0.0332 (7)	−0.0029 (6)	0.0057 (6)	0.0006 (6)
C11	0.0362 (8)	0.0314 (8)	0.0396 (8)	−0.0013 (6)	0.0027 (6)	−0.0007 (6)
N1	0.0601 (9)	0.0264 (7)	0.0500 (8)	−0.0006 (7)	−0.0105 (7)	0.0017 (6)
N2	0.0395 (8)	0.0319 (8)	0.0681 (10)	−0.0003 (6)	−0.0104 (7)	−0.0006 (7)
O1	0.0488 (6)	0.0315 (6)	0.0356 (6)	−0.0036 (5)	−0.0013 (5)	0.0013 (4)
O2	0.0493 (7)	0.0264 (6)	0.0435 (6)	−0.0016 (5)	−0.0016 (5)	−0.0010 (4)
O3	0.0354 (6)	0.0327 (6)	0.0434 (6)	0.0021 (4)	−0.0042 (4)	−0.0033 (5)
O4	0.0482 (7)	0.0296 (6)	0.0675 (8)	−0.0049 (5)	−0.0071 (6)	0.0007 (5)

Geometric parameters (Å, º)

C1—C2	1.387 (2)	C8—H81	0.964 (17)
C1—C6	1.387 (3)	C8—H82	0.984 (19)
C1—C7	1.517 (2)	C9—O3	1.4420 (18)
C2—C3	1.381 (2)	C9—H91	0.998 (19)
C2—H2	1.00 (2)	C9—H92	1.008 (18)
C3—C4	1.373 (3)	C10—O2	1.2212 (18)
C3—H3	0.95 (2)	C10—N1	1.328 (2)
C4—C5	1.373 (3)	C10—O1	1.3429 (18)
C4—H4	0.95 (2)	C11—O4	1.2152 (19)
C5—C6	1.382 (3)	C11—N2	1.331 (2)
C5—H5	0.97 (2)	C11—O3	1.3451 (19)
C6—H6	0.98 (2)	N1—H11	0.87 (2)
C7—C8	1.523 (2)	N1—H12	0.92 (2)
C7—C9	1.527 (2)	N2—H21	0.90 (2)
C7—H7	0.959 (17)	N2—H22	0.89 (2)
C8—O1	1.4478 (19)
C2—C1—C6	117.95 (15)	O1—C8—H81	108.0 (9)
C2—C1—C7	119.98 (15)	C7—C8—H81	111.6 (9)
C6—C1—C7	122.07 (15)	O1—C8—H82	102.4 (11)
C3—C2—C1	121.08 (18)	C7—C8—H82	110.3 (10)
C3—C2—H2	120.9 (11)	H81—C8—H82	112.2 (14)
C1—C2—H2	118.0 (11)	O3—C9—C7	106.97 (13)
C4—C3—C2	120.20 (18)	O3—C9—H91	110.6 (10)
C4—C3—H3	119.3 (13)	C7—C9—H91	111.5 (10)
C2—C3—H3	120.4 (13)	O3—C9—H92	109.2 (10)
C5—C4—C3	119.52 (17)	C7—C9—H92	109.2 (10)
C5—C4—H4	118.8 (12)	H91—C9—H92	109.4 (14)
C3—C4—H4	121.6 (12)	O2—C10—N1	124.24 (15)
C4—C5—C6	120.5 (2)	O2—C10—O1	123.90 (14)
C4—C5—H5	119.9 (13)	N1—C10—O1	111.85 (13)
C6—C5—H5	119.6 (13)	O4—C11—N2	125.47 (15)
C5—C6—C1	120.74 (18)	O4—C11—O3	124.12 (14)
C5—C6—H6	119.9 (12)	N2—C11—O3	110.40 (14)
C1—C6—H6	119.3 (12)	C10—N1—H11	120.7 (13)
C1—C7—C8	110.29 (13)	C10—N1—H12	117.9 (14)
C1—C7—C9	110.07 (13)	H11—N1—H12	120.1 (19)
C8—C7—C9	113.80 (13)	C11—N2—H21	117.4 (14)
C1—C7—H7	108.9 (9)	C11—N2—H22	118.3 (14)
C8—C7—H7	105.9 (9)	H21—N2—H22	121 (2)
C9—C7—H7	107.6 (9)	C10—O1—C8	117.15 (12)
O1—C8—C7	112.08 (13)	C11—O3—C9	118.47 (12)
C6—C1—C2—C3	0.3 (3)	C6—C1—C7—C9	−85.1 (2)
C7—C1—C2—C3	−179.72 (16)	C1—C7—C8—O1	162.85 (13)
C1—C2—C3—C4	0.1 (3)	C9—C7—C8—O1	−72.89 (18)
C2—C3—C4—C5	−0.4 (3)	C1—C7—C9—O3	−161.33 (13)
C3—C4—C5—C6	0.4 (3)	C8—C7—C9—O3	74.29 (17)
C4—C5—C6—C1	−0.1 (3)	O2—C10—O1—C8	−1.6 (2)
C2—C1—C6—C5	−0.2 (3)	N1—C10—O1—C8	177.84 (14)
C7—C1—C6—C5	179.75 (18)	C7—C8—O1—C10	101.11 (16)
C2—C1—C7—C8	−138.71 (16)	O4—C11—O3—C9	−3.9 (2)
C6—C1—C7—C8	41.3 (2)	N2—C11—O3—C9	177.11 (14)
C2—C1—C7—C9	94.91 (18)	C7—C9—O3—C11	−155.06 (13)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H11···O2^i	0.87 (2)	2.14 (2)	2.963 (2)	158.1 (18)
N1—H12···O4^ii	0.92 (2)	2.12 (2)	3.033 (2)	176.7 (18)
N2—H21···O2^ii	0.90 (2)	2.04 (2)	2.943 (2)	180 (2)
N2—H22···O4^i	0.89 (2)	2.14 (2)	2.991 (2)	160.7 (19)

Symmetry codes: (i) x, y−1, z; (ii) −x+1, −y, −z+1.