(RS)-2-[(Furan-2-carbon­yl)amino]propionic acid

In the asymmetric unit of the title compound, C₈H₉NO₄, there is a pair of independent mol­ecules in different conformations. Each of these conformers forms a dimer via a pair of N—H...O hydrogen bonds with the respective enanti­omer. The enanti­omers within each dimer are related by inversion. The dimers are connected by strong O—H...O hydrogen bonds. In addition, there are C—H...O hydrogen bonds, as well as π–π inter­actions, between the furan rings of each dimer. Bond lengths and angles are unexceptional.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.043
• wR factor = 0.132
• Data-to-parameter ratio = 12.4

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT230_ALERT_2_B Hirshfeld Test Diff for    O1     -   C4      ..       8.82 su
PLAT230_ALERT_2_B Hirshfeld Test Diff for    C2     -   C3      ..       9.05 su

Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal (x 10000)         200 Deg.
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C3     -   C4      ..       6.70 su

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

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

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Computing details

Data collection: SMART (Bruker, 1999); cell refinement: SAINT-Plus (Bruker, 1999); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL.

(RS)-2-[(Furan-2-carbonyl)amino]propionic acid

Crystal data

C8H9NO4	Z = 4
Mr = 183.16	F(000) = 384
Triclinic, P1	Dx = 1.432 Mg m^−3
Hall symbol: -P 1	Melting point: 442 K
a = 8.4240 (11) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.1388 (13) Å	Cell parameters from 4361 reflections
c = 10.8220 (14) Å	θ = 2.2–27.0°
α = 104.146 (2)°	µ = 0.12 mm^−1
β = 94.137 (2)°	T = 173 K
γ = 106.413 (2)°	Block, colourless
V = 849.78 (19) Å^3	0.48 × 0.46 × 0.16 mm

Data collection

Bruker SMART 1K CCD area-detector diffractometer	2954 independent reflections
Radiation source: fine-focus sealed tube	2547 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.016
φ and ω scans	θmax = 25.0°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −10→9
Tmin = 0.946, Tmax = 0.982	k = −12→12
6167 measured reflections	l = −12→12

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.043	Hydrogen site location: difference Fourier map
wR(F^2) = 0.132	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0727P)^2 + 0.4583P] where P = (Fo^2 + 2Fc^2)/3
2954 reflections	(Δ/σ)max = 0.001
239 parameters	Δρmax = 0.45 e Å^−3
0 restraints	Δρmin = −0.36 e Å^−3
68 constraints

Special details

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.

The diffractions -1 1 0, -2 2 0, -3 3 0, -5 5 0, -8 4 0 were omitted from the refinement since their F_o were significantly lower than F_c from the calculated model. The refinement with these diffractions included convergerd to the indicators of refinement: _refine_ls_R_factor_all 0.0525 _refine_ls_R_factor_gt 0.0445 _refine_ls_wR_factor_ref 0.1508 _refine_ls_wR_factor_gt 0.1324 _refine_ls_goodness_of_fit_ref 1.082 _refine_ls_restrained_S_all 1.082 _refine_ls_shift/su_max 0.008 _refine_ls_shift/su_mean 0.002 _refine_ls_weighting_details 'calc w=1/[σ²(F_o²)+(0.0925P)²+0.4254P] where P=(F_o²+2Fc²)/3' _refine_ls_extinction_method none _refine_diff_density_max 0.469 _refine_diff_density_min -0.362

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O7	0.88533 (17)	0.48529 (14)	0.17458 (12)	0.0294 (3)
O6	0.82914 (17)	0.77792 (15)	0.15239 (13)	0.0328 (3)
O8	0.60495 (17)	0.40647 (16)	0.14406 (14)	0.0358 (4)
H8	0.6191	0.3686	0.2031	0.054*
O5	1.14504 (18)	0.82727 (15)	−0.04796 (14)	0.0354 (4)
N2	0.87554 (19)	0.62377 (16)	−0.01770 (15)	0.0265 (4)
H2	0.9374	0.6062	−0.0780	0.032*
C13	0.9166 (2)	0.7531 (2)	0.06724 (18)	0.0262 (4)
C15	0.7514 (2)	0.46839 (19)	0.11436 (18)	0.0255 (4)
C12	1.0662 (2)	0.8620 (2)	0.05472 (19)	0.0282 (4)
C14	0.7273 (2)	0.5130 (2)	−0.00867 (18)	0.0268 (4)
H14	0.6314	0.5529	−0.0053	0.032*
C11	1.1446 (3)	0.9965 (2)	0.12720 (19)	0.0315 (4)
H11	1.1138	1.0456	0.2036	0.038*
C9	1.2780 (3)	0.9454 (3)	−0.0385 (2)	0.0389 (5)
H9	1.3558	0.9520	−0.0977	0.047*
C16	0.6842 (3)	0.3842 (2)	−0.12639 (19)	0.0358 (5)
H16A	0.7775	0.3442	−0.1322	0.054*
H16B	0.6642	0.4139	−0.2042	0.054*
H16C	0.5832	0.3115	−0.1187	0.054*
C10	1.2833 (3)	1.0505 (2)	0.0660 (2)	0.0392 (5)
H10	1.3639	1.1429	0.0939	0.047*
O4	0.86090 (18)	0.01481 (16)	0.32185 (14)	0.0382 (4)
H4	0.8421	−0.0650	0.2677	0.057*
O2	0.61859 (18)	0.26684 (15)	0.31252 (13)	0.0344 (4)
O3	0.58716 (18)	−0.06618 (15)	0.32960 (13)	0.0349 (4)
N1	0.6097 (2)	0.20140 (17)	0.49555 (15)	0.0284 (4)
H1	0.5589	0.1915	0.5625	0.034*
O1	0.3228 (2)	0.34143 (18)	0.34330 (16)	0.0478 (4)
C7	0.7229 (2)	0.0227 (2)	0.36757 (18)	0.0270 (4)
C5	0.5510 (2)	0.25636 (19)	0.40916 (18)	0.0271 (4)
C4	0.4056 (2)	0.3051 (2)	0.43500 (19)	0.0295 (4)
C6	0.7586 (2)	0.1580 (2)	0.47817 (18)	0.0303 (4)
H6	0.8454	0.2367	0.4578	0.036*
C3	0.3388 (3)	0.3241 (2)	0.54376 (19)	0.0333 (5)
H3	0.3728	0.3047	0.6213	0.040*
C8	0.8276 (3)	0.1338 (3)	0.6018 (2)	0.0445 (6)
H8A	0.7394	0.0653	0.6289	0.067*
H8B	0.8664	0.2248	0.6696	0.067*
H8C	0.9214	0.0958	0.5865	0.067*
C1	0.1975 (3)	0.3867 (3)	0.3992 (3)	0.0474 (6)
H1A	0.1181	0.4180	0.3571	0.057*
C2	0.2050 (3)	0.3799 (3)	0.5187 (3)	0.0516 (7)
H2A	0.1345	0.4071	0.5781	0.062*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O7	0.0283 (7)	0.0336 (7)	0.0266 (7)	0.0106 (6)	0.0059 (6)	0.0072 (6)
O6	0.0356 (8)	0.0305 (7)	0.0345 (8)	0.0123 (6)	0.0147 (6)	0.0079 (6)
O8	0.0289 (8)	0.0443 (9)	0.0360 (8)	0.0056 (6)	0.0076 (6)	0.0203 (7)
O5	0.0335 (8)	0.0355 (8)	0.0351 (8)	0.0079 (6)	0.0098 (6)	0.0081 (6)
N2	0.0273 (8)	0.0273 (8)	0.0261 (8)	0.0081 (7)	0.0101 (6)	0.0081 (7)
C13	0.0274 (10)	0.0269 (10)	0.0277 (10)	0.0113 (8)	0.0049 (8)	0.0098 (8)
C15	0.0273 (10)	0.0225 (9)	0.0261 (9)	0.0080 (8)	0.0077 (8)	0.0041 (7)
C12	0.0280 (10)	0.0308 (10)	0.0299 (10)	0.0120 (8)	0.0062 (8)	0.0117 (8)
C14	0.0243 (9)	0.0272 (10)	0.0287 (10)	0.0073 (8)	0.0059 (7)	0.0078 (8)
C11	0.0345 (11)	0.0313 (10)	0.0282 (10)	0.0109 (9)	0.0028 (8)	0.0068 (8)
C9	0.0264 (11)	0.0501 (13)	0.0412 (12)	0.0059 (9)	0.0081 (9)	0.0202 (11)
C16	0.0380 (12)	0.0345 (11)	0.0280 (10)	0.0036 (9)	0.0028 (8)	0.0060 (9)
C10	0.0325 (11)	0.0327 (11)	0.0464 (13)	−0.0006 (9)	−0.0027 (9)	0.0150 (10)
O4	0.0324 (8)	0.0389 (8)	0.0380 (8)	0.0133 (6)	0.0093 (6)	−0.0024 (7)
O2	0.0405 (8)	0.0362 (8)	0.0315 (8)	0.0143 (6)	0.0136 (6)	0.0134 (6)
O3	0.0346 (8)	0.0331 (8)	0.0323 (8)	0.0049 (7)	0.0097 (6)	0.0060 (6)
N1	0.0314 (9)	0.0331 (9)	0.0241 (8)	0.0130 (7)	0.0103 (7)	0.0086 (7)
O1	0.0506 (10)	0.0528 (10)	0.0462 (10)	0.0217 (8)	0.0104 (8)	0.0174 (8)
C7	0.0310 (11)	0.0301 (10)	0.0243 (9)	0.0123 (9)	0.0075 (8)	0.0112 (8)
C5	0.0314 (10)	0.0209 (9)	0.0260 (10)	0.0051 (8)	0.0080 (8)	0.0034 (7)
C4	0.0286 (10)	0.0237 (9)	0.0342 (11)	0.0068 (8)	0.0022 (8)	0.0067 (8)
C6	0.0300 (10)	0.0334 (11)	0.0271 (10)	0.0121 (8)	0.0061 (8)	0.0045 (8)
C3	0.0319 (11)	0.0406 (12)	0.0219 (9)	0.0030 (9)	0.0034 (8)	0.0085 (8)
C8	0.0454 (13)	0.0618 (15)	0.0297 (11)	0.0285 (12)	0.0025 (9)	0.0058 (10)
C1	0.0376 (13)	0.0435 (13)	0.0653 (17)	0.0215 (11)	0.0044 (11)	0.0130 (12)
C2	0.0353 (13)	0.0507 (14)	0.0546 (16)	0.0070 (11)	0.0178 (11)	−0.0066 (12)

Geometric parameters (Å, º)

O7—C15	1.207 (2)	O4—C7	1.311 (2)
O6—C13	1.243 (2)	O4—H4	0.8400
O8—C15	1.318 (2)	O2—C5	1.239 (2)
O8—H8	0.8400	O3—C7	1.207 (2)
O5—C12	1.359 (2)	N1—C5	1.332 (3)
O5—C9	1.365 (3)	N1—C6	1.451 (2)
N2—C13	1.339 (2)	N1—H1	0.8800
N2—C14	1.453 (2)	O1—C4	1.353 (3)
N2—H2	0.8800	O1—C1	1.386 (3)
C13—C12	1.462 (3)	C7—C6	1.522 (3)
C15—C14	1.525 (3)	C5—C4	1.465 (3)
C12—C11	1.343 (3)	C4—C3	1.336 (3)
C14—C16	1.520 (3)	C6—C8	1.522 (3)
C14—H14	1.0000	C6—H6	1.0000
C11—C10	1.425 (3)	C3—C2	1.434 (3)
C11—H11	0.9500	C3—H3	0.9500
C9—C10	1.339 (3)	C8—H8A	0.9800
C9—H9	0.9500	C8—H8B	0.9800
C16—H16A	0.9800	C8—H8C	0.9800
C16—H16B	0.9800	C1—C2	1.310 (4)
C16—H16C	0.9800	C1—H1A	0.9500
C10—H10	0.9500	C2—H2A	0.9500
C15—O8—H8	109.5	C7—O4—H4	109.5
C12—O5—C9	106.07 (16)	C5—N1—C6	119.31 (16)
C13—N2—C14	118.93 (15)	C5—N1—H1	120.3
C13—N2—H2	120.5	C6—N1—H1	120.3
C14—N2—H2	120.5	C4—O1—C1	106.02 (18)
O6—C13—N2	120.54 (17)	O3—C7—O4	124.96 (18)
O6—C13—C12	122.12 (17)	O3—C7—C6	124.59 (17)
N2—C13—C12	117.34 (16)	O4—C7—C6	110.43 (16)
O7—C15—O8	124.96 (17)	O2—C5—N1	120.92 (18)
O7—C15—C14	124.87 (17)	O2—C5—C4	122.11 (18)
O8—C15—C14	110.15 (16)	N1—C5—C4	116.97 (17)
C11—C12—O5	110.86 (17)	C3—C4—O1	110.99 (18)
C11—C12—C13	131.79 (18)	C3—C4—C5	128.52 (19)
O5—C12—C13	117.35 (17)	O1—C4—C5	120.47 (18)
N2—C14—C16	110.92 (15)	N1—C6—C8	110.23 (16)
N2—C14—C15	110.72 (15)	N1—C6—C7	111.58 (16)
C16—C14—C15	110.55 (16)	C8—C6—C7	109.64 (17)
N2—C14—H14	108.2	N1—C6—H6	108.4
C16—C14—H14	108.2	C8—C6—H6	108.4
C15—C14—H14	108.2	C7—C6—H6	108.4
C12—C11—C10	105.98 (18)	C4—C3—C2	105.47 (19)
C12—C11—H11	127.0	C4—C3—H3	127.3
C10—C11—H11	127.0	C2—C3—H3	127.3
C10—C9—O5	110.53 (18)	C6—C8—H8A	109.5
C10—C9—H9	124.7	C6—C8—H8B	109.5
O5—C9—H9	124.7	H8A—C8—H8B	109.5
C14—C16—H16A	109.5	C6—C8—H8C	109.5
C14—C16—H16B	109.5	H8A—C8—H8C	109.5
H16A—C16—H16B	109.5	H8B—C8—H8C	109.5
C14—C16—H16C	109.5	C2—C1—O1	109.8 (2)
H16A—C16—H16C	109.5	C2—C1—H1A	125.1
H16B—C16—H16C	109.5	O1—C1—H1A	125.1
C9—C10—C11	106.56 (18)	C1—C2—C3	107.6 (2)
C9—C10—H10	126.7	C1—C2—H2A	126.2
C11—C10—H10	126.7	C3—C2—H2A	126.2
C14—N2—C13—O6	−0.1 (3)	C6—N1—C5—O2	2.2 (3)
C14—N2—C13—C12	−179.73 (16)	C6—N1—C5—C4	−176.92 (16)
C9—O5—C12—C11	0.1 (2)	C1—O1—C4—C3	0.5 (2)
C9—O5—C12—C13	179.53 (17)	C1—O1—C4—C5	−178.05 (18)
O6—C13—C12—C11	4.6 (3)	O2—C5—C4—C3	−167.0 (2)
N2—C13—C12—C11	−175.8 (2)	N1—C5—C4—C3	12.1 (3)
O6—C13—C12—O5	−174.75 (17)	O2—C5—C4—O1	11.2 (3)
N2—C13—C12—O5	4.9 (3)	N1—C5—C4—O1	−169.72 (17)
C13—N2—C14—C16	169.72 (17)	C5—N1—C6—C8	166.01 (18)
C13—N2—C14—C15	−67.2 (2)	C5—N1—C6—C7	−71.9 (2)
O7—C15—C14—N2	−21.9 (3)	O3—C7—C6—N1	−25.3 (3)
O8—C15—C14—N2	159.21 (15)	O4—C7—C6—N1	156.30 (16)
O7—C15—C14—C16	101.4 (2)	O3—C7—C6—C8	97.1 (2)
O8—C15—C14—C16	−77.5 (2)	O4—C7—C6—C8	−81.3 (2)
O5—C12—C11—C10	−0.2 (2)	O1—C4—C3—C2	−1.3 (2)
C13—C12—C11—C10	−179.6 (2)	C5—C4—C3—C2	177.04 (19)
C12—O5—C9—C10	0.1 (2)	C4—O1—C1—C2	0.7 (3)
O5—C9—C10—C11	−0.2 (2)	O1—C1—C2—C3	−1.5 (3)
C12—C11—C10—C9	0.3 (2)	C4—C3—C2—C1	1.7 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O8—H8···O2	0.84	1.75	2.581 (2)	171
N2—H2···O7^i	0.88	2.17	3.000 (2)	157
O4—H4···O6^ii	0.84	1.74	2.572 (2)	173
N1—H1···O3^iii	0.88	2.13	2.941 (2)	153
N2—H2···O5	0.88	2.35	2.704 (2)	104
C11—H11···O4^iv	0.95	2.55	3.312 (3)	138
C14—H14···O8^v	1.00	2.59	3.454 (2)	144

Symmetry codes: (i) −x+2, −y+1, −z; (ii) x, y−1, z; (iii) −x+1, −y, −z+1; (iv) x, y+1, z; (v) −x+1, −y+1, −z.