Diethyl 4,6-diacetamido-isophthalate.

In the title compound, C(16)H(20)N(2)O(6), two intra-molecular N-H⋯O hydrogen bonds occur, in which the carbonyl O atoms of the ethyl acetate groups serve as the acceptor atoms; both motifs generate S(6) rings. In the crystal, mol-ecules are linked by weak C-H⋯O links (with the acceptor O atoms part of the amide groups), generating [001] chains.

Related literature

For background to intra­molecular hydrogen bonds this class of compound, see: Zhu et al. (2000 ▶); Yuan et al. (2004 ▶); Feng et al. (2009 ▶); Yan et al. (2010 ▶); Zhang et al. (2008 ▶). For a related structure, see: Zhang et al. (2006 ▶).

Experimental

Crystal data

C16H20N2O6

M = 336.34

Triclinic,

a = 7.951 (3) Å

b = 10.249 (3) Å

c = 11.109 (4) Å

α = 76.70 (3)°

β = 77.42 (3)°

γ = 76.50 (2)°

V = 843.7 (5) Å3

Z = 2

Mo Kα radiation

μ = 0.10 mm−1

T = 292 K

0.50 × 0.46 × 0.40 mm

Data collection

Enraf–Nonius CAD-4 diffractometer

3149 measured reflections

3094 independent reflections

1826 reflections with I > 2σ(I)

R int = 0.004

3 standard reflections every 150 reflections intensity decay: 4.5%

Refinement

R[F 2 > 2σ(F 2)] = 0.079

wR(F 2) = 0.268

S = 1.09

3094 reflections

223 parameters

4 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.59 e Å−3

Δρmin = −0.65 e Å−3

Data collection: DIFRAC (Gabe et al., 1993 ▶); cell refinement: DIFRAC; data reduction: NRCVAX (Gabe et al., 1989 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811013845/hb5828sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811013845/hb5828Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C16H20N2O6	Z = 2
Mr = 336.34	F(000) = 356
Triclinic, P1	Dx = 1.324 Mg m−3
a = 7.951 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.249 (3) Å	Cell parameters from 20 reflections
c = 11.109 (4) Å	θ = 5.4–6.7°
α = 76.70 (3)°	µ = 0.10 mm−1
β = 77.42 (3)°	T = 292 K
γ = 76.50 (2)°	Block, colourless
V = 843.7 (5) Å3	0.50 × 0.46 × 0.40 mm

Enraf–Nonius CAD-4 diffractometer	Rint = 0.004
Radiation source: fine-focus sealed tube	θmax = 25.5°, θmin = 1.9°
graphite	h = −9→9
ω/2θ scans	k = −1→12
3149 measured reflections	l = −12→13
3094 independent reflections	3 standard reflections every 150 reflections
1826 reflections with I > 2σ(I)	intensity decay: 4.5%

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.079	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.268	H atoms treated by a mixture of independent and constrained refinement
S = 1.09	w = 1/[σ2(Fo2) + (0.1639P)2 + 0.1078P] where P = (Fo2 + 2Fc2)/3
3094 reflections	(Δ/σ)max < 0.001
223 parameters	Δρmax = 0.59 e Å−3
4 restraints	Δρmin = −0.65 e Å−3

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.

	x	y	z	Uiso*/Ueq
O1	0.9467 (4)	−0.1465 (3)	0.6464 (2)	0.0692 (9)
O2	1.1334 (4)	−0.2976 (3)	0.7586 (2)	0.0706 (9)
O3	1.0473 (5)	−0.3487 (3)	1.2179 (3)	0.0988 (12)
O4	0.7415 (4)	−0.0447 (3)	1.3243 (3)	0.0796 (9)
O5	0.5572 (4)	0.2164 (3)	0.7774 (3)	0.0692 (8)
O6	0.5009 (4)	0.2628 (3)	0.9676 (3)	0.0718 (8)
N1	1.0637 (4)	−0.3063 (3)	1.0068 (3)	0.0503 (8)
H1N	1.113 (4)	−0.338 (4)	0.938 (3)	0.046 (9)*
N2	0.6413 (4)	0.0776 (3)	1.1468 (3)	0.0514 (8)
H2N	0.581 (5)	0.150 (4)	1.120 (3)	0.044 (10)*
C1	0.9150 (4)	−0.1332 (4)	0.8583 (3)	0.0477 (8)
C2	0.9442 (4)	−0.1847 (3)	0.9824 (3)	0.0427 (8)
C3	0.8541 (4)	−0.1138 (3)	1.0777 (3)	0.0440 (8)
H3	0.8745	−0.1477	1.1594	0.053*
C4	0.7336 (4)	0.0075 (3)	1.0518 (3)	0.0413 (8)
C5	0.7021 (4)	0.0591 (3)	0.9291 (3)	0.0449 (8)
C6	0.7941 (4)	−0.0127 (3)	0.8356 (3)	0.0460 (8)
H6	0.7736	0.0216	0.7539	0.055*
C7	1.0103 (5)	−0.2022 (4)	0.7527 (3)	0.0539 (9)
C8	1.0398 (7)	−0.1987 (5)	0.5319 (4)	0.0871 (15)
H8A	1.1655	−0.2192	0.5310	0.104*
H8B	1.0160	−0.1303	0.4581	0.104*
C9	0.9772 (8)	−0.3269 (6)	0.5304 (5)	0.1008 (17)
H9A	1.0175	−0.3987	0.5961	0.151*
H9B	1.0233	−0.3543	0.4507	0.151*
H9C	0.8512	−0.3090	0.5434	0.151*
C10	1.1082 (5)	−0.3819 (4)	1.1169 (4)	0.0574 (10)
C11	1.2385 (6)	−0.5100 (4)	1.1039 (4)	0.0680 (11)
H11A	1.2382	−0.5696	1.1844	0.102*
H11B	1.3533	−0.4888	1.0722	0.102*
H11C	1.2081	−0.5544	1.0466	0.102*
C12	0.6424 (5)	0.0486 (4)	1.2735 (3)	0.0544 (9)
C13	0.5091 (6)	0.1480 (5)	1.3433 (4)	0.0723 (12)
H13A	0.3951	0.1530	1.3249	0.108*
H13B	0.5399	0.2367	1.3177	0.108*
H13C	0.5073	0.1177	1.4320	0.108*
C14	0.5778 (5)	0.1888 (4)	0.8965 (4)	0.0531 (9)
C15	0.4366 (9)	0.3443 (6)	0.7425 (5)	0.1109 (14)
H15A	0.4848	0.4216	0.7463	0.133*
H15B	0.3245	0.3465	0.7987	0.133*
C16	0.4146 (9)	0.3488 (6)	0.6092 (5)	0.1109 (14)
H16A	0.3796	0.2666	0.6051	0.166*
H16B	0.5239	0.3565	0.5534	0.166*
H16C	0.3262	0.4263	0.5848	0.166*

	U11	U22	U33	U12	U13	U23
O1	0.0823 (19)	0.0772 (19)	0.0456 (15)	0.0082 (15)	−0.0164 (13)	−0.0255 (13)
O2	0.0655 (17)	0.0820 (19)	0.0598 (17)	0.0178 (15)	−0.0127 (13)	−0.0357 (14)
O3	0.130 (3)	0.084 (2)	0.0577 (19)	0.040 (2)	−0.0244 (18)	−0.0185 (16)
O4	0.094 (2)	0.082 (2)	0.0529 (16)	0.0193 (18)	−0.0208 (15)	−0.0222 (14)
O5	0.0774 (19)	0.0613 (16)	0.0625 (17)	0.0094 (14)	−0.0272 (14)	−0.0076 (13)
O6	0.083 (2)	0.0520 (15)	0.0749 (19)	0.0166 (14)	−0.0225 (15)	−0.0227 (14)
N1	0.0532 (17)	0.0460 (16)	0.0500 (17)	0.0046 (13)	−0.0107 (14)	−0.0184 (13)
N2	0.0526 (18)	0.0501 (18)	0.0507 (18)	0.0036 (15)	−0.0115 (14)	−0.0189 (14)
C1	0.0476 (19)	0.0513 (19)	0.0465 (19)	−0.0098 (16)	−0.0054 (15)	−0.0161 (15)
C2	0.0392 (17)	0.0438 (17)	0.0469 (18)	−0.0060 (14)	−0.0068 (14)	−0.0147 (14)
C3	0.0455 (18)	0.0449 (18)	0.0428 (18)	−0.0052 (15)	−0.0074 (14)	−0.0147 (14)
C4	0.0353 (16)	0.0430 (17)	0.0480 (18)	−0.0066 (14)	−0.0029 (13)	−0.0182 (14)
C5	0.0436 (18)	0.0433 (18)	0.0492 (19)	−0.0035 (15)	−0.0102 (15)	−0.0143 (15)
C6	0.0485 (19)	0.0480 (18)	0.0430 (17)	−0.0067 (15)	−0.0100 (14)	−0.0120 (14)
C7	0.055 (2)	0.058 (2)	0.051 (2)	−0.0040 (18)	−0.0062 (16)	−0.0240 (17)
C8	0.105 (4)	0.096 (3)	0.054 (2)	0.007 (3)	−0.009 (2)	−0.032 (2)
C9	0.121 (4)	0.107 (4)	0.081 (3)	0.002 (3)	−0.026 (3)	−0.048 (3)
C10	0.058 (2)	0.051 (2)	0.062 (2)	0.0021 (17)	−0.0145 (18)	−0.0186 (18)
C11	0.076 (3)	0.048 (2)	0.077 (3)	0.0043 (19)	−0.021 (2)	−0.0148 (19)
C12	0.056 (2)	0.060 (2)	0.050 (2)	−0.0067 (18)	−0.0058 (17)	−0.0237 (17)
C13	0.071 (3)	0.081 (3)	0.063 (2)	0.005 (2)	−0.005 (2)	−0.035 (2)
C14	0.058 (2)	0.0453 (19)	0.058 (2)	−0.0045 (17)	−0.0150 (17)	−0.0146 (16)
C15	0.130 (3)	0.087 (3)	0.103 (3)	0.021 (2)	−0.050 (3)	−0.008 (2)
C16	0.130 (3)	0.087 (3)	0.103 (3)	0.021 (2)	−0.050 (3)	−0.008 (2)

O1—C7	1.338 (4)	C5—C14	1.482 (5)
O1—C8	1.474 (5)	C6—H6	0.9300
O2—C7	1.212 (4)	C8—C9	1.514 (6)
O3—C10	1.212 (5)	C8—H8A	0.9700
O4—C12	1.204 (5)	C8—H8B	0.9700
O5—C14	1.326 (4)	C9—H9A	0.9600
O5—C15	1.459 (5)	C9—H9B	0.9600
O6—C14	1.192 (4)	C9—H9C	0.9600
N1—C10	1.359 (5)	C10—C11	1.485 (5)
N1—C2	1.390 (4)	C11—H11A	0.9600
N1—H1N	0.88 (4)	C11—H11B	0.9600
N2—C12	1.371 (5)	C11—H11C	0.9600
N2—C4	1.391 (4)	C12—C13	1.505 (5)
N2—H2N	0.81 (4)	C13—H13A	0.9600
C1—C6	1.386 (5)	C13—H13B	0.9600
C1—C2	1.408 (5)	C13—H13C	0.9600
C1—C7	1.482 (5)	C15—C16	1.517 (7)
C2—C3	1.393 (4)	C15—H15A	0.9700
C3—C4	1.395 (4)	C15—H15B	0.9700
C3—H3	0.9300	C16—H16A	0.9600
C4—C5	1.398 (5)	C16—H16B	0.9600
C5—C6	1.388 (4)	C16—H16C	0.9600
C7—O1—C8	117.5 (3)	H9A—C9—H9B	109.5
C14—O5—C15	114.2 (3)	C8—C9—H9C	109.5
C10—N1—C2	130.8 (3)	H9A—C9—H9C	109.5
C10—N1—H1N	117 (2)	H9B—C9—H9C	109.5
C2—N1—H1N	112 (2)	O3—C10—N1	123.3 (3)
C12—N2—C4	131.2 (3)	O3—C10—C11	122.3 (4)
C12—N2—H2N	116 (3)	N1—C10—C11	114.4 (3)
C4—N2—H2N	112 (3)	C10—C11—H11A	109.5
C6—C1—C2	118.0 (3)	C10—C11—H11B	109.5
C6—C1—C7	119.7 (3)	H11A—C11—H11B	109.5
C2—C1—C7	122.3 (3)	C10—C11—H11C	109.5
N1—C2—C3	121.5 (3)	H11A—C11—H11C	109.5
N1—C2—C1	118.7 (3)	H11B—C11—H11C	109.5
C3—C2—C1	119.9 (3)	O4—C12—N2	124.0 (3)
C2—C3—C4	120.7 (3)	O4—C12—C13	122.9 (4)
C2—C3—H3	119.6	N2—C12—C13	113.1 (3)
C4—C3—H3	119.6	C12—C13—H13A	109.5
N2—C4—C3	121.0 (3)	C12—C13—H13B	109.5
N2—C4—C5	119.0 (3)	H13A—C13—H13B	109.5
C3—C4—C5	120.0 (3)	C12—C13—H13C	109.5
C6—C5—C4	118.3 (3)	H13A—C13—H13C	109.5
C6—C5—C14	119.7 (3)	H13B—C13—H13C	109.5
C4—C5—C14	122.0 (3)	O6—C14—O5	121.7 (3)
C1—C6—C5	123.0 (3)	O6—C14—C5	125.2 (3)
C1—C6—H6	118.5	O5—C14—C5	113.1 (3)
C5—C6—H6	118.5	O5—C15—C16	106.1 (4)
O2—C7—O1	122.4 (3)	O5—C15—H15A	110.5
O2—C7—C1	125.2 (3)	C16—C15—H15A	110.5
O1—C7—C1	112.4 (3)	O5—C15—H15B	110.5
O1—C8—C9	108.6 (4)	C16—C15—H15B	110.5
O1—C8—H8A	110.0	H15A—C15—H15B	108.7
C9—C8—H8A	110.0	C15—C16—H16A	109.5
O1—C8—H8B	110.0	C15—C16—H16B	109.5
C9—C8—H8B	110.0	H16A—C16—H16B	109.5
H8A—C8—H8B	108.3	C15—C16—H16C	109.5
C8—C9—H9A	109.5	H16A—C16—H16C	109.5
C8—C9—H9B	109.5	H16B—C16—H16C	109.5
C10—N1—C2—C3	4.6 (6)	C14—C5—C6—C1	178.7 (3)
C10—N1—C2—C1	−175.5 (3)	C8—O1—C7—O2	−4.3 (6)
C6—C1—C2—N1	179.3 (3)	C8—O1—C7—C1	175.0 (3)
C7—C1—C2—N1	−1.5 (5)	C6—C1—C7—O2	170.3 (4)
C6—C1—C2—C3	−0.8 (5)	C2—C1—C7—O2	−8.9 (6)
C7—C1—C2—C3	178.4 (3)	C6—C1—C7—O1	−9.1 (5)
N1—C2—C3—C4	−179.5 (3)	C2—C1—C7—O1	171.8 (3)
C1—C2—C3—C4	0.6 (5)	C7—O1—C8—C9	83.1 (5)
C12—N2—C4—C3	−1.0 (6)	C2—N1—C10—O3	−2.1 (7)
C12—N2—C4—C5	178.0 (3)	C2—N1—C10—C11	177.7 (3)
C2—C3—C4—N2	179.0 (3)	C4—N2—C12—O4	6.1 (7)
C2—C3—C4—C5	0.0 (5)	C4—N2—C12—C13	−175.2 (3)
N2—C4—C5—C6	−179.4 (3)	C15—O5—C14—O6	1.0 (6)
C3—C4—C5—C6	−0.4 (5)	C15—O5—C14—C5	−179.4 (4)
N2—C4—C5—C14	2.1 (5)	C6—C5—C14—O6	−174.9 (4)
C3—C4—C5—C14	−178.9 (3)	C4—C5—C14—O6	3.6 (6)
C2—C1—C6—C5	0.4 (5)	C6—C5—C14—O5	5.6 (5)
C7—C1—C6—C5	−178.8 (3)	C4—C5—C14—O5	−176.0 (3)
C4—C5—C6—C1	0.2 (5)	C14—O5—C15—C16	−173.5 (4)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O2	0.88 (4)	1.92 (3)	2.676 (4)	144 (3)
N2—H2N···O6	0.81 (4)	1.96 (4)	2.656 (4)	143 (3)
C9—H9B···O3i	0.96	2.54	3.445 (6)	157
C16—H16A···O4ii	0.96	2.57	3.485 (7)	160

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O2	0.88 (4)	1.92 (3)	2.676 (4)	144 (3)
N2—H2N⋯O6	0.81 (4)	1.96 (4)	2.656 (4)	143 (3)
C9—H9B⋯O3i	0.96	2.54	3.445 (6)	157
C16—H16A⋯O4ii	0.96	2.57	3.485 (7)	160

Symmetry codes: (i) ; (ii) .