Di-tert-butyl 3,5-dimethyl-1H-pyrrole-2,4-dicarboxyl-ate.

In the title mol-ecule, C(16)H(25)NO(4), the non-H atoms, except for the two tert-butyl groups, are roughly planar (r.m.s. deviation of the non-H atoms = 0.086 Å). In the crystal, mol-ecules are linked into inversion dimers by pairs of N-H⋯O hydrogen bonds, forming R(2) (2)(10) ring motifs.

Related literature

For complexes of Schiff bases containing a pyrrole unit, see: Wu et al. (2003 ▶); Wang et al. (2008 ▶). For the synthesis of the title compound, see: Sun et al. (2003 ▶).

Experimental

Crystal data

C16H25NO4

M = 295.37

Triclinic,

a = 5.8976 (10) Å

b = 11.511 (2) Å

c = 13.460 (2) Å

α = 103.956 (4)°

β = 90.078 (3)°

γ = 104.804 (3)°

V = 855.5 (3) Å3

Z = 2

Mo Kα radiation

μ = 0.08 mm−1

T = 296 K

0.21 × 0.19 × 0.16 mm

Data collection

Bruker SMART CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T min = 0.983, T max = 0.987

4496 measured reflections

2989 independent reflections

1704 reflections with I > 2σ(I)

R int = 0.023

Refinement

R[F 2 > 2σ(F 2)] = 0.058

wR(F 2) = 0.150

S = 1.04

2989 reflections

191 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.27 e Å−3

Δρmin = −0.21 e Å−3

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812026700/vm2177sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812026700/vm2177Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536812026700/vm2177Isup3.cml

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

C16H25NO4	Z = 2
Mr = 295.37	F(000) = 320
Triclinic, P1	Dx = 1.147 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.8976 (10) Å	Cell parameters from 771 reflections
b = 11.511 (2) Å	θ = 3.2–20.5°
c = 13.460 (2) Å	µ = 0.08 mm−1
α = 103.956 (4)°	T = 296 K
β = 90.078 (3)°	Plate, colorless
γ = 104.804 (3)°	0.21 × 0.19 × 0.16 mm
V = 855.5 (3) Å3

Bruker SMART CCD diffractometer	2989 independent reflections
Radiation source: fine-focus sealed tube	1704 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.023
φ and ω scans	θmax = 25.0°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Bruker, 2007)	h = −6→6
Tmin = 0.983, Tmax = 0.987	k = −13→13
4496 measured reflections	l = −16→13

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)] = 0.058	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.150	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ2(Fo2) + (0.0557P)2 + 0.202P] where P = (Fo2 + 2Fc2)/3
2989 reflections	(Δ/σ)max < 0.001
191 parameters	Δρmax = 0.27 e Å−3
0 restraints	Δρmin = −0.21 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
C1	−0.2311 (4)	0.1845 (2)	−0.08222 (19)	0.0471 (7)
C2	−0.1610 (4)	0.2579 (2)	−0.14921 (19)	0.0476 (7)
C3	−0.3401 (5)	0.2180 (2)	−0.23018 (19)	0.0478 (7)
C4	−0.5147 (5)	0.1215 (2)	−0.2090 (2)	0.0484 (7)
C5	0.0637 (5)	0.3586 (3)	−0.1403 (2)	0.0673 (9)
H5A	0.1527	0.3670	−0.0781	0.101*
H5B	0.0276	0.4356	−0.1393	0.101*
H5C	0.1540	0.3375	−0.1980	0.101*
C6	−0.7463 (5)	0.0472 (3)	−0.2626 (2)	0.0691 (9)
H6A	−0.8212	−0.0121	−0.2255	0.104*
H6B	−0.7229	0.0045	−0.3308	0.104*
H6C	−0.8440	0.1015	−0.2660	0.104*
C7	−0.1316 (4)	0.1787 (2)	0.0145 (2)	0.0479 (7)
C8	0.1962 (5)	0.2870 (3)	0.1451 (2)	0.0537 (7)
C9	0.2769 (5)	0.1727 (3)	0.1469 (2)	0.0726 (9)
H9A	0.3721	0.1553	0.0903	0.109*
H9B	0.1424	0.1032	0.1415	0.109*
H9C	0.3674	0.1870	0.2101	0.109*
C10	0.0441 (5)	0.3201 (3)	0.2315 (2)	0.0693 (9)
H10A	−0.0005	0.3935	0.2274	0.104*
H10B	0.1301	0.3351	0.2960	0.104*
H10C	−0.0944	0.2529	0.2263	0.104*
C11	0.4029 (6)	0.3960 (3)	0.1429 (3)	0.0819 (10)
H11A	0.3469	0.4670	0.1417	0.123*
H11B	0.4861	0.3754	0.0827	0.123*
H11C	0.5067	0.4147	0.2030	0.123*
C12	−0.3408 (5)	0.2728 (3)	−0.3174 (2)	0.0549 (7)
C13	−0.5671 (6)	0.2464 (3)	−0.4787 (2)	0.0673 (9)
C14	−0.3574 (7)	0.2685 (4)	−0.5428 (3)	0.1043 (13)
H14A	−0.3103	0.1930	−0.5657	0.156*
H14B	−0.2298	0.3317	−0.5022	0.156*
H14C	−0.3990	0.2948	−0.6012	0.156*
C15	−0.6498 (7)	0.3616 (4)	−0.4426 (3)	0.1023 (13)
H15A	−0.7827	0.3448	−0.4023	0.153*
H15B	−0.6943	0.3873	−0.5009	0.153*
H15C	−0.5252	0.4265	−0.4017	0.153*
C16	−0.7630 (8)	0.1391 (4)	−0.5360 (3)	0.1329 (19)
H16A	−0.8932	0.1267	−0.4935	0.199*
H16B	−0.7085	0.0654	−0.5536	0.199*
H16C	−0.8123	0.1567	−0.5976	0.199*
N1	−0.4459 (4)	0.10303 (19)	−0.12068 (16)	0.0492 (6)
H1A	−0.526 (2)	0.0471 (17)	−0.0913 (9)	0.059*
O1	−0.2209 (3)	0.10146 (17)	0.06093 (14)	0.0565 (5)
O2	0.0654 (3)	0.26788 (16)	0.04613 (13)	0.0594 (6)
O3	−0.2064 (4)	0.3672 (2)	−0.32547 (15)	0.0789 (7)
O4	−0.5120 (4)	0.20430 (18)	−0.38930 (14)	0.0728 (7)

	U11	U22	U33	U12	U13	U23
C1	0.0392 (15)	0.0471 (16)	0.0494 (16)	0.0026 (13)	−0.0034 (13)	0.0109 (13)
C2	0.0431 (16)	0.0459 (16)	0.0501 (16)	0.0040 (13)	0.0011 (13)	0.0133 (13)
C3	0.0487 (17)	0.0433 (15)	0.0484 (16)	0.0059 (13)	−0.0017 (13)	0.0123 (12)
C4	0.0481 (17)	0.0447 (16)	0.0490 (16)	0.0062 (13)	−0.0060 (13)	0.0117 (13)
C5	0.0580 (19)	0.069 (2)	0.066 (2)	−0.0086 (16)	−0.0064 (16)	0.0271 (16)
C6	0.062 (2)	0.065 (2)	0.068 (2)	−0.0084 (16)	−0.0152 (16)	0.0191 (16)
C7	0.0364 (15)	0.0501 (16)	0.0511 (16)	0.0022 (13)	−0.0015 (13)	0.0109 (14)
C8	0.0435 (16)	0.0598 (18)	0.0503 (17)	0.0019 (14)	−0.0090 (13)	0.0121 (14)
C9	0.056 (2)	0.088 (2)	0.078 (2)	0.0266 (18)	−0.0060 (16)	0.0190 (18)
C10	0.068 (2)	0.070 (2)	0.064 (2)	0.0160 (17)	0.0038 (17)	0.0075 (16)
C11	0.058 (2)	0.089 (2)	0.079 (2)	−0.0151 (18)	−0.0104 (17)	0.0205 (18)
C12	0.0551 (18)	0.0514 (18)	0.0541 (17)	0.0048 (15)	−0.0033 (15)	0.0152 (14)
C13	0.067 (2)	0.075 (2)	0.0572 (19)	0.0036 (17)	−0.0113 (17)	0.0290 (16)
C14	0.103 (3)	0.154 (4)	0.063 (2)	0.040 (3)	0.009 (2)	0.033 (2)
C15	0.105 (3)	0.133 (4)	0.092 (3)	0.050 (3)	0.004 (2)	0.050 (2)
C16	0.137 (4)	0.125 (3)	0.107 (3)	−0.041 (3)	−0.073 (3)	0.053 (3)
N1	0.0457 (14)	0.0490 (13)	0.0491 (13)	0.0005 (11)	−0.0029 (11)	0.0181 (11)
O1	0.0495 (12)	0.0582 (12)	0.0572 (12)	−0.0030 (9)	−0.0060 (9)	0.0240 (10)
O2	0.0486 (12)	0.0636 (13)	0.0566 (12)	−0.0083 (10)	−0.0105 (9)	0.0220 (9)
O3	0.0853 (16)	0.0726 (15)	0.0676 (14)	−0.0133 (13)	−0.0132 (12)	0.0327 (11)
O4	0.0795 (15)	0.0684 (14)	0.0620 (13)	−0.0075 (11)	−0.0240 (11)	0.0292 (11)

C1—C2	1.375 (3)	C9—H9C	0.9600
C1—N1	1.381 (3)	C10—H10A	0.9600
C1—C7	1.450 (4)	C10—H10B	0.9600
C2—C3	1.422 (3)	C10—H10C	0.9600
C2—C5	1.504 (3)	C11—H11A	0.9600
C3—C4	1.394 (3)	C11—H11B	0.9600
C3—C12	1.462 (4)	C11—H11C	0.9600
C4—N1	1.337 (3)	C12—O3	1.200 (3)
C4—C6	1.490 (3)	C12—O4	1.342 (3)
C5—H5A	0.9600	C13—O4	1.466 (3)
C5—H5B	0.9600	C13—C15	1.502 (5)
C5—H5C	0.9600	C13—C16	1.505 (4)
C6—H6A	0.9600	C13—C14	1.512 (5)
C6—H6B	0.9600	C14—H14A	0.9600
C6—H6C	0.9600	C14—H14B	0.9600
C7—O1	1.220 (3)	C14—H14C	0.9600
C7—O2	1.328 (3)	C15—H15A	0.9600
C8—O2	1.479 (3)	C15—H15B	0.9600
C8—C10	1.506 (4)	C15—H15C	0.9600
C8—C9	1.514 (4)	C16—H16A	0.9600
C8—C11	1.516 (4)	C16—H16B	0.9600
C9—H9A	0.9600	C16—H16C	0.9600
C9—H9B	0.9600	N1—H1A	0.873 (17)
C2—C1—N1	107.7 (2)	C8—C10—H10C	109.5
C2—C1—C7	134.1 (2)	H10A—C10—H10C	109.5
N1—C1—C7	118.2 (2)	H10B—C10—H10C	109.5
C1—C2—C3	106.5 (2)	C8—C11—H11A	109.5
C1—C2—C5	126.9 (2)	C8—C11—H11B	109.5
C3—C2—C5	126.6 (2)	H11A—C11—H11B	109.5
C4—C3—C2	107.8 (2)	C8—C11—H11C	109.5
C4—C3—C12	127.0 (2)	H11A—C11—H11C	109.5
C2—C3—C12	125.2 (2)	H11B—C11—H11C	109.5
N1—C4—C3	107.2 (2)	O3—C12—O4	123.1 (3)
N1—C4—C6	120.3 (2)	O3—C12—C3	125.1 (3)
C3—C4—C6	132.5 (2)	O4—C12—C3	111.8 (2)
C2—C5—H5A	109.5	O4—C13—C15	108.9 (3)
C2—C5—H5B	109.5	O4—C13—C16	102.4 (2)
H5A—C5—H5B	109.5	C15—C13—C16	111.3 (3)
C2—C5—H5C	109.5	O4—C13—C14	111.3 (3)
H5A—C5—H5C	109.5	C15—C13—C14	111.4 (3)
H5B—C5—H5C	109.5	C16—C13—C14	111.2 (3)
C4—C6—H6A	109.5	C13—C14—H14A	109.5
C4—C6—H6B	109.5	C13—C14—H14B	109.5
H6A—C6—H6B	109.5	H14A—C14—H14B	109.5
C4—C6—H6C	109.5	C13—C14—H14C	109.5
H6A—C6—H6C	109.5	H14A—C14—H14C	109.5
H6B—C6—H6C	109.5	H14B—C14—H14C	109.5
O1—C7—O2	124.6 (2)	C13—C15—H15A	109.5
O1—C7—C1	123.5 (2)	C13—C15—H15B	109.5
O2—C7—C1	111.9 (2)	H15A—C15—H15B	109.5
O2—C8—C10	109.2 (2)	C13—C15—H15C	109.5
O2—C8—C9	109.9 (2)	H15A—C15—H15C	109.5
C10—C8—C9	112.8 (2)	H15B—C15—H15C	109.5
O2—C8—C11	101.8 (2)	C13—C16—H16A	109.5
C10—C8—C11	111.4 (2)	C13—C16—H16B	109.5
C9—C8—C11	111.2 (3)	H16A—C16—H16B	109.5
C8—C9—H9A	109.5	C13—C16—H16C	109.5
C8—C9—H9B	109.5	H16A—C16—H16C	109.5
H9A—C9—H9B	109.5	H16B—C16—H16C	109.5
C8—C9—H9C	109.5	C4—N1—C1	110.9 (2)
H9A—C9—H9C	109.5	C4—N1—H1A	124.5 (8)
H9B—C9—H9C	109.5	C1—N1—H1A	124.6 (8)
C8—C10—H10A	109.5	C7—O2—C8	122.9 (2)
C8—C10—H10B	109.5	C12—O4—C13	122.3 (2)
H10A—C10—H10B	109.5
N1—C1—C2—C3	−0.3 (3)	C2—C3—C12—O3	−9.7 (5)
C7—C1—C2—C3	−179.0 (3)	C4—C3—C12—O4	−12.0 (4)
N1—C1—C2—C5	−178.9 (2)	C2—C3—C12—O4	170.3 (2)
C7—C1—C2—C5	2.5 (5)	C3—C4—N1—C1	0.2 (3)
C1—C2—C3—C4	0.4 (3)	C6—C4—N1—C1	−177.7 (2)
C5—C2—C3—C4	179.0 (3)	C2—C1—N1—C4	0.1 (3)
C1—C2—C3—C12	178.5 (3)	C7—C1—N1—C4	179.0 (2)
C5—C2—C3—C12	−3.0 (4)	O1—C7—O2—C8	−2.5 (4)
C2—C3—C4—N1	−0.3 (3)	C1—C7—O2—C8	176.8 (2)
C12—C3—C4—N1	−178.3 (3)	C10—C8—O2—C7	−63.0 (3)
C2—C3—C4—C6	177.1 (3)	C9—C8—O2—C7	61.2 (3)
C12—C3—C4—C6	−0.9 (5)	C11—C8—O2—C7	179.2 (2)
C2—C1—C7—O1	−177.3 (3)	O3—C12—O4—C13	−7.2 (5)
N1—C1—C7—O1	4.1 (4)	C3—C12—O4—C13	172.8 (3)
C2—C1—C7—O2	3.3 (4)	C15—C13—O4—C12	−63.2 (4)
N1—C1—C7—O2	−175.2 (2)	C16—C13—O4—C12	178.9 (3)
C4—C3—C12—O3	168.0 (3)	C14—C13—O4—C12	60.0 (4)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O1i	0.873 (17)	2.087 (18)	2.933 (3)	163.2 (12)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯O1i	0.873 (17)	2.087 (18)	2.933 (3)	163.2 (12)

Symmetry code: (i) .