1,3,6-Trimethyl­pyrano[4,3-b]pyrrol-4(1H)-one

Abstract

All the non-H atoms of the title compound, C₁₀H₁₁NO₂, are almost coplanar [maximum deviation = 0.040 (3) Å]. The crystal structure is stabilized by C—H⋯O hydrogen bonds.

Related literature

For general background to isocoumarins, see: Barry (1964 ▶). For related structures, see: Abid et al. (2006 ▶, 2008 ▶); Hathwar et al. (2007 ▶).

Experimental

Crystal data

• C₁₀H₁₁NO₂

• M _r = 177.20

• Monoclinic,

• a = 7.5556 (7) Å

• b = 8.4819 (8) Å

• c = 14.3081 (14) Å

• β = 93.870 (6)°

• V = 914.86 (15) ų

• Z = 4

• Mo Kα radiation

• μ = 0.09 mm⁻¹

• T = 295 K

• 0.33 × 0.28 × 0.15 mm

Data collection

• Oxford Xcalibur Eos (Nova) CCD detector diffractometer

• Absorption correction: multi-scan (CrysAlis PRO RED; Oxford Diffraction, 2009 ▶) T _min = 0.916, T _max = 0.987

• 7291 measured reflections

• 1692 independent reflections

• 1176 reflections with I > 2σ(I)

• R _int = 0.034

Refinement

• R[F ² > 2σ(F ²)] = 0.051

• wR(F ²) = 0.179

• S = 1.18

• 1692 reflections

• 122 parameters

• H-atom parameters constrained

• Δρ_max = 0.27 e Å⁻³

• Δρ_min = −0.18 e Å⁻³

Data collection: CrysAlis PRO CCD (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis PRO CCD; data reduction: CrysAlis PRO RED (Oxford Diffraction, 2009 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and CAMERON (Watkin et al., 1993 ▶); software used to prepare material for publication: WinGX (Farrugia, 1997 ▶).

Supplementary Material

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C10—H10B⋯O1i	0.96	2.46	3.404 (3)	170

Symmetry code: (i) .

supplementary crystallographic information

Comment

Isocoumarins (Barry, 1964) are also useful intermediates in the synthesis of a variety of important compounds including some carbocyclic and heterocyclic compounds. In view of their natural occurrence, biological activities and utility as synthetic intermediates, we have synthesized the title compound, and reported herein its crystal structure.

Experimental

A mixture of 2-(carboxymethyl)-1, 4-dimethyl-1H-pyrrole-3-carboxylic acid (2 mmol) and acetic anhydride (8 mmol) in the presence of pyridine was refluxed for 4 h. Completion of the reaction was monitored by Thin Layer Chromatography. After completing of the reaction, the mixture was poured into crushed ice. The solids were separated and purified by silica gel column chromatography. The product was obtained with 90% yield.

Refinement

All the H atoms were positioned geometrically and refined using a riding model, fixing the bond lengths at 0.96 and 0.93 Å for CH₃ aromatic CH, respectively. The displacement parameters of the H atoms were constrained as U_iso(H) = 1.2U_eq (1.5U_eq for methyl) of the carrier atom.

Figures

Fig. 1.

A view of the title complex, showing 50% probability displacement ellipsoids and the atom-numbering scheme.

Fig. 2.

The packing diagram depicting C—H···O intermolecular interactions.

Crystal data

C10H11NO2	F(000) = 376
Mr = 177.20	Dx = 1.287 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1235 reflections
a = 7.5556 (7) Å	θ = 2.9–20.4°
b = 8.4819 (8) Å	µ = 0.09 mm−1
c = 14.3081 (14) Å	T = 295 K
β = 93.870 (6)°	Block, colorless
V = 914.86 (15) Å3	0.33 × 0.28 × 0.15 mm
Z = 4

Data collection

Oxford Xcalibur Eos (Nova) CCD detector diffractometer	1692 independent reflections
Radiation source: Enhance (Mo) X-ray Source	1176 reflections with I > 2σ(I)
graphite	Rint = 0.034
ω scans	θmax = 25.5°, θmin = 2.8°
Absorption correction: multi-scan (CrysAlis PRO RED; Oxford Diffraction, 2009)	h = −9→9
Tmin = 0.916, Tmax = 0.987	k = −9→10
7291 measured reflections	l = −17→17

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.051	H-atom parameters constrained
wR(F2) = 0.179	w = 1/[σ2(Fo2) + (0.0888P)2 + 0.144P] where P = (Fo2 + 2Fc2)/3
S = 1.18	(Δ/σ)max < 0.001
1692 reflections	Δρmax = 0.27 e Å−3
122 parameters	Δρmin = −0.18 e Å−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.004 (1)

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

	x	y	z	Uiso*/Ueq
N1	0.1293 (2)	0.4172 (2)	0.87406 (12)	0.0412 (5)
O1	0.3720 (3)	0.1280 (3)	1.12304 (13)	0.0818 (7)
O2	0.3792 (2)	0.3881 (2)	1.13262 (10)	0.0586 (6)
C1	0.1778 (3)	0.1674 (3)	0.92158 (16)	0.0466 (6)
C2	0.1079 (3)	0.2591 (3)	0.85100 (16)	0.0466 (6)
H2	0.0534	0.2216	0.7951	0.056*
C3	0.2612 (3)	0.5620 (3)	1.01528 (16)	0.0460 (6)
H3	0.2372	0.6633	0.9929	0.055*
C4	0.3421 (3)	0.5382 (3)	1.09968 (17)	0.0507 (7)
C5	0.3331 (3)	0.2497 (3)	1.08310 (16)	0.0526 (7)
C6	0.2454 (3)	0.2744 (3)	0.99253 (14)	0.0420 (6)
C7	0.2128 (3)	0.4269 (2)	0.96087 (14)	0.0389 (6)
C8	0.4000 (4)	0.6605 (4)	1.1693 (2)	0.0749 (9)
H8A	0.3742	0.7631	1.1435	0.112*
H8B	0.5253	0.6511	1.1842	0.112*
H8C	0.3380	0.6465	1.2251	0.112*
C9	0.1882 (4)	−0.0092 (3)	0.9237 (2)	0.0702 (9)
H9A	0.1145	−0.0518	0.8725	0.105*
H9B	0.1480	−0.0472	0.9818	0.105*
H9C	0.3087	−0.0416	0.9181	0.105*
C10	0.0743 (4)	0.5500 (3)	0.81496 (17)	0.0551 (7)
H10A	0.0008	0.6192	0.8487	0.083*
H10B	0.0085	0.5123	0.7597	0.083*
H10C	0.1771	0.6063	0.7974	0.083*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
N1	0.0466 (11)	0.0379 (11)	0.0382 (10)	0.0025 (8)	−0.0049 (8)	0.0018 (8)
O1	0.1038 (17)	0.0781 (16)	0.0623 (12)	0.0317 (12)	−0.0034 (11)	0.0266 (11)
O2	0.0562 (11)	0.0777 (14)	0.0403 (9)	0.0065 (9)	−0.0082 (7)	−0.0015 (9)
C1	0.0506 (13)	0.0375 (13)	0.0521 (14)	−0.0005 (11)	0.0074 (11)	−0.0007 (11)
C2	0.0488 (13)	0.0463 (14)	0.0442 (12)	−0.0021 (11)	−0.0008 (10)	−0.0089 (12)
C3	0.0474 (13)	0.0415 (14)	0.0489 (13)	−0.0035 (10)	0.0016 (10)	−0.0050 (10)
C4	0.0443 (13)	0.0604 (17)	0.0471 (13)	−0.0021 (12)	0.0015 (10)	−0.0097 (11)
C5	0.0541 (15)	0.0589 (17)	0.0448 (13)	0.0102 (13)	0.0022 (11)	0.0066 (13)
C6	0.0432 (12)	0.0416 (13)	0.0409 (12)	0.0030 (10)	0.0017 (9)	0.0050 (10)
C7	0.0392 (12)	0.0400 (13)	0.0372 (11)	0.0023 (10)	0.0005 (9)	0.0033 (9)
C8	0.0654 (18)	0.096 (2)	0.0630 (17)	−0.0162 (17)	−0.0004 (13)	−0.0329 (16)
C9	0.085 (2)	0.0395 (16)	0.087 (2)	0.0000 (15)	0.0159 (16)	−0.0025 (15)
C10	0.0634 (16)	0.0556 (17)	0.0450 (13)	0.0061 (13)	−0.0055 (11)	0.0116 (11)

Geometric parameters (Å, °)

N1—C7	1.357 (3)	C4—C8	1.483 (4)
N1—C2	1.388 (3)	C5—C6	1.431 (3)
N1—C10	1.452 (3)	C6—C7	1.387 (3)
O1—C5	1.206 (3)	C8—H8A	0.9600
O2—C4	1.380 (3)	C8—H8B	0.9600
O2—C5	1.403 (3)	C8—H8C	0.9600
C1—C2	1.353 (3)	C9—H9A	0.9600
C1—C6	1.430 (3)	C9—H9B	0.9600
C1—C9	1.500 (4)	C9—H9C	0.9600
C2—H2	0.9300	C10—H10A	0.9600
C3—C4	1.332 (3)	C10—H10B	0.9600
C3—C7	1.419 (3)	C10—H10C	0.9600
C3—H3	0.9300
C7—N1—C2	108.41 (19)	N1—C7—C6	107.66 (19)
C7—N1—C10	125.64 (19)	N1—C7—C3	129.6 (2)
C2—N1—C10	125.94 (19)	C6—C7—C3	122.7 (2)
C4—O2—C5	124.21 (19)	C4—C8—H8A	109.5
C2—C1—C6	105.5 (2)	C4—C8—H8B	109.5
C2—C1—C9	127.3 (2)	H8A—C8—H8B	109.5
C6—C1—C9	127.2 (2)	C4—C8—H8C	109.5
C1—C2—N1	110.2 (2)	H8A—C8—H8C	109.5
C1—C2—H2	124.9	H8B—C8—H8C	109.5
N1—C2—H2	124.9	C1—C9—H9A	109.5
C4—C3—C7	117.4 (2)	C1—C9—H9B	109.5
C4—C3—H3	121.3	H9A—C9—H9B	109.5
C7—C3—H3	121.3	C1—C9—H9C	109.5
C3—C4—O2	121.3 (2)	H9A—C9—H9C	109.5
C3—C4—C8	126.8 (3)	H9B—C9—H9C	109.5
O2—C4—C8	111.9 (2)	N1—C10—H10A	109.5
O1—C5—O2	115.6 (2)	N1—C10—H10B	109.5
O1—C5—C6	129.6 (3)	H10A—C10—H10B	109.5
O2—C5—C6	114.8 (2)	N1—C10—H10C	109.5
C7—C6—C1	108.3 (2)	H10A—C10—H10C	109.5
C7—C6—C5	119.6 (2)	H10B—C10—H10C	109.5
C1—C6—C5	132.2 (2)
C6—C1—C2—N1	0.3 (2)	O1—C5—C6—C7	179.4 (2)
C9—C1—C2—N1	−177.7 (2)	O2—C5—C6—C7	0.0 (3)
C7—N1—C2—C1	−0.5 (2)	O1—C5—C6—C1	−0.4 (4)
C10—N1—C2—C1	178.7 (2)	O2—C5—C6—C1	−179.8 (2)
C7—C3—C4—O2	0.6 (3)	C2—N1—C7—C6	0.4 (2)
C7—C3—C4—C8	−178.2 (2)	C10—N1—C7—C6	−178.74 (19)
C5—O2—C4—C3	−1.5 (3)	C2—N1—C7—C3	−178.8 (2)
C5—O2—C4—C8	177.5 (2)	C10—N1—C7—C3	2.1 (4)
C4—O2—C5—O1	−178.4 (2)	C1—C6—C7—N1	−0.2 (2)
C4—O2—C5—C6	1.1 (3)	C5—C6—C7—N1	179.96 (18)
C2—C1—C6—C7	−0.1 (2)	C1—C6—C7—C3	179.06 (19)
C9—C1—C6—C7	177.9 (2)	C5—C6—C7—C3	−0.8 (3)
C2—C1—C6—C5	179.7 (2)	C4—C3—C7—N1	179.6 (2)
C9—C1—C6—C5	−2.2 (4)	C4—C3—C7—C6	0.5 (3)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
C10—H10B···O1i	0.96	2.46	3.404 (3)	170

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