5-(Amino­methyl­ene)-2,2-dimethyl-1,3-dioxane-4,6-dione

In the title compound C₇H₉NO₄, the 1,3-dioxane-4,6-dione ring exhibits an envelope conformation. Inter­molecular hydrogen bonds connect the mol­ecules into chains. One intra­molecular N—H...O hydrogen bond to a carbonyl O atom is also observed, forming a six-membered ring.

Key indicators

• Single-crystal X-ray study
• T = 299 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.037
• wR factor = 0.103
• Data-to-parameter ratio = 10.4

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.15

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 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
   1 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: CAD-4 Software (Nonius, 1996); cell refinement: CAD-4 Software; data reduction: REDU4 (Stoe & Cie, 1987); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.

5-(Aminomethylene)-2,2-dimethyl-1,3-dioxane-4,6-dione

Crystal data

C7H9NO4	F(000) = 720
Mr = 171.15	Dx = 1.431 Mg m^−3
Monoclinic, C2/c	Cu Kα radiation, λ = 1.54180 Å
Hall symbol: -C 2yc	Cell parameters from 25 reflections
a = 9.830 (1) Å	θ = 6.9–21.6°
b = 9.609 (1) Å	µ = 1.02 mm^−1
c = 16.819 (2) Å	T = 299 K
β = 90.95 (1)°	Prism, colourless
V = 1588.4 (3) Å^3	0.20 × 0.15 × 0.10 mm
Z = 8

Data collection

Nonius CAD-4 diffractometer	Rint = 0.030
Radiation source: fine-focus sealed tube	θmax = 66.9°, θmin = 5.3°
Graphite monochromator	h = −11→11
ω/2θ scans	k = −11→0
1667 measured reflections	l = −20→2
1420 independent reflections	3 standard reflections every 120 min
1063 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: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.037	Only H-atom coordinates refined
wR(F^2) = 0.103	w = 1/[σ^2(Fo^2) + (0.0544P)^2 + 0.1561P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max = 0.004
1420 reflections	Δρmax = 0.19 e Å^−3
137 parameters	Δρmin = −0.13 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: 0.0016 (2)

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
C1	0.6466 (2)	0.4391 (2)	0.66911 (12)	0.0403 (5)
H1	0.689 (2)	0.453 (2)	0.7204 (13)	0.048*
C2	0.66179 (19)	0.30712 (18)	0.63814 (11)	0.0355 (4)
C3	0.60701 (17)	0.26959 (18)	0.56139 (10)	0.0329 (4)
C4	0.64782 (19)	0.03201 (19)	0.59874 (11)	0.0371 (4)
C5	0.7467 (2)	0.21068 (19)	0.68230 (12)	0.0417 (5)
C6	0.7055 (3)	−0.0943 (2)	0.55881 (15)	0.0487 (5)
H6A	0.736 (2)	−0.162 (2)	0.5992 (14)	0.058*
H6B	0.784 (2)	−0.070 (3)	0.5301 (14)	0.058*
H6C	0.639 (2)	−0.136 (2)	0.5222 (14)	0.058*
C7	0.5179 (2)	0.0036 (2)	0.64149 (13)	0.0487 (5)
H7A	0.482 (2)	0.089 (3)	0.6654 (14)	0.058*
H7B	0.452 (2)	−0.030 (2)	0.6046 (14)	0.058*
H7C	0.534 (2)	−0.072 (3)	0.6816 (14)	0.058*
N1	0.58076 (19)	0.54454 (19)	0.63843 (11)	0.0484 (5)
H11N	0.544 (2)	0.537 (2)	0.5928 (15)	0.058*
H12N	0.579 (2)	0.625 (3)	0.6697 (14)	0.058*
O1	0.62560 (13)	0.13499 (13)	0.53788 (7)	0.0358 (3)
O2	0.75203 (14)	0.07861 (13)	0.65398 (8)	0.0440 (4)
O3	0.54988 (14)	0.34806 (14)	0.51509 (8)	0.0445 (4)
O4	0.81619 (17)	0.23814 (15)	0.74028 (10)	0.0633 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0475 (11)	0.0389 (10)	0.0343 (10)	−0.0040 (9)	−0.0117 (8)	−0.0002 (8)
C2	0.0422 (10)	0.0328 (9)	0.0310 (9)	−0.0014 (8)	−0.0101 (8)	0.0010 (8)
C3	0.0358 (9)	0.0318 (9)	0.0311 (9)	−0.0010 (7)	−0.0049 (7)	0.0013 (7)
C4	0.0449 (10)	0.0339 (10)	0.0322 (9)	−0.0039 (8)	−0.0120 (8)	0.0026 (8)
C5	0.0515 (11)	0.0340 (10)	0.0391 (10)	−0.0052 (8)	−0.0153 (9)	0.0042 (8)
C6	0.0579 (13)	0.0360 (11)	0.0519 (13)	0.0044 (10)	−0.0092 (11)	−0.0040 (10)
C7	0.0591 (14)	0.0486 (13)	0.0384 (11)	−0.0106 (10)	−0.0025 (10)	0.0039 (10)
N1	0.0641 (12)	0.0355 (9)	0.0450 (10)	0.0081 (8)	−0.0182 (9)	−0.0056 (8)
O1	0.0487 (8)	0.0315 (7)	0.0269 (6)	−0.0002 (6)	−0.0063 (5)	0.0005 (5)
O2	0.0532 (8)	0.0325 (7)	0.0457 (8)	0.0009 (6)	−0.0208 (6)	0.0017 (6)
O3	0.0567 (8)	0.0396 (7)	0.0364 (7)	0.0038 (6)	−0.0181 (6)	0.0055 (6)
O4	0.0881 (11)	0.0420 (8)	0.0583 (10)	−0.0028 (8)	−0.0466 (9)	0.0014 (7)

Geometric parameters (Å, º)

C1—N1	1.304 (3)	C5—O4	1.210 (2)
C1—C2	1.380 (3)	C5—O2	1.357 (2)
C1—H1	0.96 (2)	C6—H6A	0.98 (2)
C2—C3	1.436 (2)	C6—H6B	0.94 (2)
C2—C5	1.445 (2)	C6—H6C	0.98 (2)
C3—O3	1.215 (2)	C7—H7A	0.98 (2)
C3—O1	1.366 (2)	C7—H7B	0.95 (2)
C4—O1	1.438 (2)	C7—H7C	1.01 (2)
C4—O2	1.443 (2)	N1—H11N	0.84 (2)
C4—C7	1.501 (3)	N1—H12N	0.93 (2)
C4—C6	1.503 (3)
N1—C1—C2	128.36 (18)	C4—C6—H6A	109.6 (13)
N1—C1—H1	117.0 (13)	C4—C6—H6B	110.0 (15)
C2—C1—H1	114.7 (13)	H6A—C6—H6B	106 (2)
C1—C2—C3	121.92 (17)	C4—C6—H6C	111.3 (14)
C1—C2—C5	117.42 (16)	H6A—C6—H6C	110.8 (19)
C3—C2—C5	120.39 (16)	H6B—C6—H6C	109 (2)
O3—C3—O1	117.70 (15)	C4—C7—H7A	111.1 (14)
O3—C3—C2	125.64 (17)	C4—C7—H7B	109.0 (14)
O1—C3—C2	116.62 (15)	H7A—C7—H7B	108 (2)
O1—C4—O2	110.05 (14)	C4—C7—H7C	108.9 (12)
O1—C4—C7	110.22 (16)	H7A—C7—H7C	112.8 (19)
O2—C4—C7	110.39 (16)	H7B—C7—H7C	106.8 (19)
O1—C4—C6	106.97 (16)	C1—N1—H11N	119.6 (16)
O2—C4—C6	105.61 (16)	C1—N1—H12N	115.5 (14)
C7—C4—C6	113.45 (19)	H11N—N1—H12N	125 (2)
O4—C5—O2	117.54 (17)	C3—O1—C4	117.72 (13)
O4—C5—C2	126.02 (18)	C5—O2—C4	119.04 (14)
O2—C5—C2	116.40 (15)
N1—C1—C2—C3	2.6 (3)	O3—C3—O1—C4	−158.75 (16)
N1—C1—C2—C5	176.7 (2)	C2—C3—O1—C4	23.5 (2)
C1—C2—C3—O3	4.0 (3)	O2—C4—O1—C3	−49.2 (2)
C5—C2—C3—O3	−169.83 (19)	C7—C4—O1—C3	72.73 (19)
C1—C2—C3—O1	−178.45 (18)	C6—C4—O1—C3	−163.51 (16)
C5—C2—C3—O1	7.7 (3)	O4—C5—O2—C4	164.55 (19)
C1—C2—C5—O4	−7.3 (3)	C2—C5—O2—C4	−17.7 (3)
C3—C2—C5—O4	166.9 (2)	O1—C4—O2—C5	46.4 (2)
C1—C2—C5—O2	175.20 (18)	C7—C4—O2—C5	−75.5 (2)
C3—C2—C5—O2	−10.7 (3)	C6—C4—O2—C5	161.51 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H11N···O3	0.84 (2)	2.24 (2)	2.818 (2)	126 (2)
N1—H11N···O3^i	0.84 (2)	2.30 (2)	3.045 (2)	146 (2)
N1—H12N···O4^ii	0.93 (2)	2.12 (2)	2.929 (2)	145 (2)
C1—H1···O2^ii	0.96 (2)	2.50 (2)	3.398 (2)	156.7 (17)

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+3/2, y+1/2, −z+3/2.