cis-3-Aza­bicyclo­[3.2.0]heptane-2,4-dione

The title compound, C₆H₇NO₂, was synthesized from cis-1,2-cyclo­butane­dicarboxylic anhydride by reaction with ammonium acetate under microwave conditions. The crystal structure of the compound shows that the cyclo­butane ring is planar with angles ranging from 89.64 (12) to 90.37 (12)°. The cis-3-aza­bicyclo­[3.2.0]heptane-2,4-dione mol­ecules are linked into a chain formation through hydrogen N—H...O=C bonds. Parallel packing is seen between two cyclo­butane rings related by inversion symmetry.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.049
• wR factor = 0.134
• Data-to-parameter ratio = 13.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT057_ALERT_3_C Correction for Absorption Required   RT(exp) ...       1.12
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature .        293 K

   0 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

   2 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
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1999); software used to prepare material for publication: SHELXTL (Bruker, 1999).

cis-3-Azabicyclo[3.2.0]heptane-2,4-dione

Crystal data

C6H7NO2	F(000) = 264
Mr = 125.13	Dx = 1.409 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54178 Å
a = 9.4771 (5) Å	Cell parameters from 79 reflections
b = 7.6956 (5) Å	θ = 2.5–27.9°
c = 8.3279 (5) Å	µ = 0.90 mm^−1
β = 103.763 (4)°	T = 293 K
V = 589.93 (6) Å^3	Chunk, colorless
Z = 4	0.58 × 0.55 × 0.40 mm

Data collection

Bruker P4 diffractometer	Rint = 0.079
Radiation source: fine-focus sealed tube	θmax = 69.0°, θmin = 4.8°
Graphite monochromator	h = −11→11
2θ/ω scans	k = 0→9
1319 measured reflections	l = −10→10
1081 independent reflections	3 standard reflections every 97 reflections
1008 reflections with I > 2σ(I)	intensity decay: none

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.049	H-atom parameters constrained
wR(F^2) = 0.134	w = 1/[σ^2(Fo^2) + (0.0725P)^2 + 0.1848P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max = 0.001
1081 reflections	Δρmax = 0.23 e Å^−3
83 parameters	Δρmin = −0.19 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.078 (12)

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.

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

	x	y	z	Uiso*/Ueq
O1	0.50754 (15)	0.45880 (17)	0.2894 (2)	0.0671 (6)
O2	0.84373 (14)	0.15003 (17)	0.10039 (18)	0.0602 (5)
N	0.65817 (15)	0.27456 (17)	0.19275 (18)	0.0438 (5)
H2B	0.6013	0.1859	0.1779	0.053*
C1	0.62272 (18)	0.4310 (2)	0.2542 (2)	0.0435 (5)
C2	0.74626 (18)	0.5536 (2)	0.26244 (19)	0.0407 (5)
H2A	0.7836	0.6076	0.3708	0.049*
C3	0.7265 (2)	0.6799 (2)	0.1142 (2)	0.0518 (5)
H3A	0.6295	0.6784	0.0424	0.062*
H3B	0.7572	0.7979	0.1456	0.062*
C4	0.8375 (2)	0.5756 (2)	0.0472 (2)	0.0501 (5)
H4A	0.9241	0.6410	0.0432	0.060*
H4B	0.7967	0.5198	−0.0581	0.060*
C5	0.85891 (16)	0.4502 (2)	0.19739 (19)	0.0399 (5)
H5A	0.9569	0.4501	0.2700	0.048*
C6	0.79288 (17)	0.2736 (2)	0.15738 (19)	0.0399 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0669 (9)	0.0389 (8)	0.1108 (13)	0.0064 (6)	0.0518 (9)	0.0041 (7)
O2	0.0627 (9)	0.0392 (7)	0.0801 (10)	0.0126 (6)	0.0197 (7)	−0.0110 (6)
N	0.0440 (8)	0.0246 (7)	0.0630 (9)	−0.0025 (5)	0.0133 (6)	−0.0030 (6)
C1	0.0534 (10)	0.0278 (8)	0.0539 (10)	0.0035 (7)	0.0218 (7)	0.0028 (6)
C2	0.0567 (10)	0.0284 (8)	0.0396 (8)	−0.0038 (6)	0.0167 (7)	−0.0037 (6)
C3	0.0674 (12)	0.0342 (9)	0.0607 (10)	0.0063 (7)	0.0289 (9)	0.0112 (7)
C4	0.0656 (11)	0.0394 (9)	0.0517 (10)	0.0018 (8)	0.0264 (8)	0.0035 (7)
C5	0.0375 (8)	0.0345 (8)	0.0461 (8)	−0.0006 (6)	0.0068 (6)	0.0006 (6)
C6	0.0420 (9)	0.0308 (8)	0.0445 (8)	0.0061 (6)	0.0055 (6)	0.0002 (6)

Geometric parameters (Å, º)

O1—C1	1.2146 (19)	C3—C4	1.531 (2)
O2—C6	1.213 (2)	C3—H3A	0.9700
N—C6	1.377 (2)	C3—H3B	0.9700
N—C1	1.380 (2)	C4—C5	1.554 (2)
N—H2B	0.8600	C4—H4A	0.9700
C1—C2	1.493 (2)	C4—H4B	0.9700
C2—C5	1.530 (2)	C5—C6	1.500 (2)
C2—C3	1.547 (2)	C5—H5A	0.9800
C2—H2A	0.9800
C6—N—C1	113.81 (13)	H3A—C3—H3B	110.9
C6—N—H2B	123.1	C3—C4—C5	90.10 (12)
C1—N—H2B	123.1	C3—C4—H4A	113.6
O1—C1—N	123.72 (15)	C5—C4—H4A	113.6
O1—C1—C2	128.14 (15)	C3—C4—H4B	113.6
N—C1—C2	108.11 (13)	C5—C4—H4B	113.6
C1—C2—C5	105.12 (13)	H4A—C4—H4B	110.9
C1—C2—C3	114.58 (15)	C6—C5—C2	105.09 (12)
C5—C2—C3	90.37 (12)	C6—C5—C4	114.57 (14)
C1—C2—H2A	114.7	C2—C5—C4	89.64 (12)
C5—C2—H2A	114.7	C6—C5—H5A	114.8
C3—C2—H2A	114.7	C2—C5—H5A	114.8
C4—C3—C2	89.88 (12)	C4—C5—H5A	114.8
C4—C3—H3A	113.7	O2—C6—N	124.25 (16)
C2—C3—H3A	113.7	O2—C6—C5	127.86 (16)
C4—C3—H3B	113.7	N—C6—C5	107.87 (13)
C2—C3—H3B	113.7
C6—N—C1—O1	178.34 (16)	C1—C2—C5—C4	114.90 (14)
C6—N—C1—C2	0.17 (19)	C3—C2—C5—C4	−0.74 (13)
O1—C1—C2—C5	−177.83 (17)	C3—C4—C5—C6	107.21 (15)
N—C1—C2—C5	0.24 (18)	C3—C4—C5—C2	0.74 (13)
O1—C1—C2—C3	−80.3 (2)	C1—N—C6—O2	−178.99 (15)
N—C1—C2—C3	97.76 (16)	C1—N—C6—C5	−0.51 (18)
C1—C2—C3—C4	−106.10 (16)	C2—C5—C6—O2	179.03 (16)
C5—C2—C3—C4	0.75 (14)	C4—C5—C6—O2	82.4 (2)
C2—C3—C4—C5	−0.74 (13)	C2—C5—C6—N	0.62 (16)
C1—C2—C5—C6	−0.51 (16)	C4—C5—C6—N	−96.05 (16)
C3—C2—C5—C6	−116.14 (14)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N—H2B···O1^i	0.86	2.08	2.9163 (19)	164

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