Methyl 2-methyl-5-oxo-4-p-tolyl-1,4,5,6,7,8-hexa­hydro­quinoline-3-carboxylate

The title compound, C₁₉H₂₁NO₃, was synthesized by the reaction of cyclo­hexane-1,3-dione, 4-methyl­benzaldehyde and methyl 3-amino­but-2-enoate in the presence of benzyl­triethyl­ammonium chloride in an aqueous medium. X-ray single-crystal analysis reveals that the heterocyclic ring and the fused six-membered ring adopt boat and envelope conformations, respectively. In the crystal structure, mol­ecules are linked by inter­molecular N—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 193 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.046
• wR factor = 0.124
• Data-to-parameter ratio = 16.8

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT063_ALERT_3_C Crystal Probably too Large for Beam Size .......       0.73 mm
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent .....          ?
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       2.60 Ratio
PLAT222_ALERT_3_C Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       3.04 Ratio

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   5 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
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion

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S1. Comment

Some of the derivatives of quinoline are naturally occurring alkaloids, so they are very attractive for their various bioactivities. For example, they have calcium modulatory properties (Rose & Draeger, 1992), antibacterial activity (Thomas et al., 2005), fungicidal activity (Prem et al., 2005), etc. As part of our programme aimed at developing new and environmentally friendly methodologies for the preparation of fine chemicals (Shi et al., 2004), we have synthesized the title compound, (I), in an aqueous medium. We report here the synthesis and crystal structure of (I).

In the molecular structure of (I) (Fig. 1, Table 1), atoms C3 and N1 deviate from the mean plane of atoms C1/C2/C4/C5 in the same direction, by 0.368 (1) and 0.166 (1) Å, respectively, so the pyridine ring adopts a boat conformation. The fused cyclohexene ring can be regarded as having an envelope conformation, with atom C8 out of the plane of atoms C1/C2/C6/C7/C9 by 0.687 (1) Å. In addition, the phenyl ring is almost perpendicular to the plane of atoms C1/C2/C4/C5, with a dihedral angle between them of 83.58 (5)°.

The crystal packing of (I) is stabilized by an intermolecular hydrogen bond (Table 2, Fig. 2).

S2. Experimental

The title compound was prepared by the reaction of 1,3-cyclohexanedione (0.22 g, 2 mmol), 4-methylbenzaldehyde (0.24 g, 2 mmol) and methyl-3-aminobut-2-enoate (0.23 g, 2 mmol) in the presence of triethylbenzylammonium chloride (0.2 g) in water (10 ml) at 298 K for 25 h (yield 83%). Single crystals of (I) suitable for X-ray diffraction were obtained by slow evaporation of an ethanol solution.

S3. Refinement

Atom H1, bonded to N1, was found in a Fourier map and refined with free coordinates and an isotropic displacement parameter. Other H atoms were positioned geometrically and treated as riding on their parent atoms with C—H = 0.95 Å and U_iso(H) = 1.2U_eq(C) for aromatic CH, C—H = 0.98 Å and U_iso(H) = 1.5U_eq(C) for methyl CH₃, C—H = 0.99 Å and U_iso(H) = 1.2U_eq(C) for methylene CH₂, and C—H = 1.00 Å and U_iso(H) = 1.2U_eq(C) for methine CH.

Computing details

Data collection: CrystalClear (Rigaku, 1999); cell refinement: CrystalClear; data reduction: CrystalStructure (Rigaku/MSC, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1999); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The structure of (I), showing 40% probability displacement ellipsoids and the atom-numbering scheme.
	Fig. 2. The molecular packing in the crystal structure of (I). Intermolecular hydrogen bonds are shown as dashed lines. H atoms not involved in hydrogen bonds have been omitted.

Methyl 2-methyl-5-oxo-4-p-tolyl-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate

Crystal data

C19H21NO3	F(000) = 664
Mr = 311.37	Dx = 1.300 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71070 Å
Hall symbol: -P 2ybc	Cell parameters from 7332 reflections
a = 7.8338 (15) Å	θ = 3.0–27.5°
b = 15.095 (3) Å	µ = 0.09 mm^−1
c = 13.962 (3) Å	T = 193 K
β = 105.436 (5)°	Block, colourless
V = 1591.5 (5) Å^3	0.73 × 0.62 × 0.25 mm
Z = 4

Data collection

Rigaku Mercury diffractometer	3637 independent reflections
Radiation source: fine-focus sealed tube	3378 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
Detector resolution: 7.31 pixels mm^-1	θmax = 27.5°, θmin = 3.0°
ω scans	h = −8→10
Absorption correction: multi-scan (Jacobson, 1998)	k = −16→19
Tmin = 0.939, Tmax = 0.978	l = −18→18
17357 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.124	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0636P)^2 + 0.5891P] where P = (Fo^2 + 2Fc^2)/3
3637 reflections	(Δ/σ)max < 0.001
216 parameters	Δρmax = 0.25 e Å^−3
0 restraints	Δρmin = −0.24 e Å^−3

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	0.39522 (14)	0.21452 (7)	0.09977 (7)	0.0346 (2)
O2	0.96668 (14)	0.41203 (9)	0.41562 (8)	0.0441 (3)
O3	0.86076 (12)	0.42985 (7)	0.25115 (7)	0.0309 (2)
N1	0.43779 (14)	0.33862 (7)	0.41278 (8)	0.0251 (2)
C1	0.35039 (16)	0.28794 (8)	0.33350 (9)	0.0220 (2)
C2	0.40187 (15)	0.28928 (8)	0.24778 (8)	0.0210 (2)
C3	0.53959 (15)	0.35590 (8)	0.23502 (8)	0.0221 (3)
H3	0.6117	0.3276	0.1941	0.027*
C4	0.66256 (16)	0.37812 (8)	0.33611 (9)	0.0230 (3)
C5	0.60375 (16)	0.37424 (8)	0.41910 (9)	0.0238 (3)
C6	0.33129 (16)	0.22424 (8)	0.17099 (9)	0.0244 (3)
C7	0.18101 (18)	0.16599 (9)	0.18145 (11)	0.0319 (3)
H7A	0.2293	0.1081	0.2093	0.038*
H7B	0.1000	0.1552	0.1148	0.038*
C8	0.07639 (18)	0.20670 (9)	0.24836 (10)	0.0309 (3)
H8A	0.0133	0.2603	0.2164	0.037*
H8B	−0.0128	0.1638	0.2585	0.037*
C9	0.20191 (18)	0.23118 (9)	0.34801 (10)	0.0294 (3)
H9A	0.1361	0.2636	0.3885	0.035*
H9B	0.2511	0.1766	0.3843	0.035*
C10	0.44748 (16)	0.43728 (8)	0.17868 (9)	0.0240 (3)
C11	0.3751 (3)	0.43195 (11)	0.07656 (11)	0.0461 (4)
H11	0.3873	0.3787	0.0427	0.055*
C12	0.2854 (3)	0.50304 (12)	0.02328 (12)	0.0546 (5)
H12	0.2369	0.4974	−0.0464	0.065*
C13	0.2648 (2)	0.58212 (10)	0.06909 (11)	0.0367 (3)
C14	0.33865 (18)	0.58778 (9)	0.17087 (10)	0.0303 (3)
H14	0.3277	0.6414	0.2044	0.036*
C15	0.42844 (16)	0.51653 (9)	0.22486 (9)	0.0266 (3)
H15	0.4775	0.5223	0.2945	0.032*
C16	0.84361 (17)	0.40792 (9)	0.34183 (9)	0.0258 (3)
C17	1.03324 (17)	0.46132 (10)	0.24855 (11)	0.0332 (3)
H17A	1.0679	0.5111	0.2947	0.050*
H17B	1.0292	0.4809	0.1811	0.050*
H17C	1.1198	0.4133	0.2681	0.050*
C18	0.69805 (19)	0.40596 (10)	0.52161 (10)	0.0333 (3)
H18A	0.7600	0.3562	0.5609	0.050*
H18B	0.6117	0.4306	0.5538	0.050*
H18C	0.7840	0.4518	0.5169	0.050*
C19	0.1671 (3)	0.65923 (12)	0.00988 (14)	0.0545 (5)
H19A	0.1741	0.7107	0.0536	0.082*
H19B	0.0427	0.6431	−0.0184	0.082*
H19C	0.2212	0.6739	−0.0439	0.082*
H1	0.404 (2)	0.3317 (12)	0.4656 (13)	0.036 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0417 (6)	0.0396 (6)	0.0250 (5)	−0.0066 (4)	0.0132 (4)	−0.0112 (4)
O2	0.0264 (5)	0.0687 (8)	0.0327 (6)	−0.0094 (5)	−0.0001 (4)	0.0002 (5)
O3	0.0225 (4)	0.0420 (6)	0.0297 (5)	−0.0061 (4)	0.0096 (4)	−0.0002 (4)
N1	0.0271 (5)	0.0338 (6)	0.0162 (5)	−0.0025 (4)	0.0088 (4)	−0.0009 (4)
C1	0.0220 (5)	0.0234 (6)	0.0204 (5)	0.0018 (4)	0.0052 (4)	0.0019 (4)
C2	0.0200 (5)	0.0234 (6)	0.0197 (5)	−0.0001 (4)	0.0053 (4)	0.0002 (4)
C3	0.0225 (6)	0.0271 (6)	0.0179 (5)	−0.0031 (5)	0.0072 (4)	−0.0024 (4)
C4	0.0216 (6)	0.0260 (6)	0.0208 (6)	−0.0009 (5)	0.0048 (4)	−0.0018 (4)
C5	0.0242 (6)	0.0264 (6)	0.0198 (6)	0.0012 (5)	0.0041 (4)	−0.0011 (4)
C6	0.0260 (6)	0.0249 (6)	0.0216 (6)	0.0008 (5)	0.0052 (5)	−0.0013 (4)
C7	0.0308 (7)	0.0294 (7)	0.0344 (7)	−0.0070 (5)	0.0068 (5)	−0.0066 (5)
C8	0.0258 (6)	0.0313 (7)	0.0360 (7)	−0.0062 (5)	0.0089 (5)	−0.0009 (5)
C9	0.0302 (6)	0.0329 (7)	0.0276 (6)	−0.0050 (5)	0.0120 (5)	0.0030 (5)
C10	0.0248 (6)	0.0281 (6)	0.0195 (6)	−0.0060 (5)	0.0064 (5)	0.0009 (4)
C11	0.0779 (12)	0.0317 (8)	0.0219 (7)	0.0030 (8)	0.0013 (7)	−0.0022 (6)
C12	0.0893 (14)	0.0386 (9)	0.0232 (7)	0.0040 (9)	−0.0070 (8)	0.0028 (6)
C13	0.0424 (8)	0.0316 (7)	0.0323 (7)	−0.0039 (6)	0.0034 (6)	0.0079 (6)
C14	0.0280 (6)	0.0288 (7)	0.0342 (7)	−0.0044 (5)	0.0084 (5)	−0.0016 (5)
C15	0.0247 (6)	0.0323 (7)	0.0228 (6)	−0.0041 (5)	0.0064 (5)	−0.0028 (5)
C16	0.0238 (6)	0.0274 (6)	0.0261 (6)	−0.0006 (5)	0.0063 (5)	−0.0034 (5)
C17	0.0244 (6)	0.0352 (7)	0.0428 (8)	−0.0043 (5)	0.0141 (6)	0.0005 (6)
C18	0.0339 (7)	0.0440 (8)	0.0199 (6)	−0.0041 (6)	0.0037 (5)	−0.0058 (5)
C19	0.0690 (12)	0.0375 (9)	0.0482 (10)	0.0043 (8)	0.0000 (9)	0.0112 (7)

Geometric parameters (Å, º)

O1—C6	1.2354 (16)	C8—H8B	0.9900
O2—C16	1.2108 (16)	C9—H9A	0.9900
O3—C16	1.3495 (16)	C9—H9B	0.9900
O3—C17	1.4418 (15)	C10—C15	1.3858 (18)
N1—C1	1.3696 (16)	C10—C11	1.3893 (19)
N1—C5	1.3878 (16)	C11—C12	1.386 (2)
N1—H1	0.854 (18)	C11—H11	0.9500
C1—C2	1.3610 (16)	C12—C13	1.384 (2)
C1—C9	1.5012 (17)	C12—H12	0.9500
C2—C6	1.4503 (17)	C13—C14	1.387 (2)
C2—C3	1.5196 (16)	C13—C19	1.512 (2)
C3—C4	1.5195 (16)	C14—C15	1.3920 (19)
C3—C10	1.5318 (17)	C14—H14	0.9500
C3—H3	1.0000	C15—H15	0.9500
C4—C5	1.3573 (17)	C17—H17A	0.9800
C4—C16	1.4697 (17)	C17—H17B	0.9800
C5—C18	1.5035 (17)	C17—H17C	0.9800
C6—C7	1.5074 (18)	C18—H18A	0.9800
C7—C8	1.526 (2)	C18—H18B	0.9800
C7—H7A	0.9900	C18—H18C	0.9800
C7—H7B	0.9900	C19—H19A	0.9800
C8—C9	1.5201 (19)	C19—H19B	0.9800
C8—H8A	0.9900	C19—H19C	0.9800
C16—O3—C17	115.62 (10)	C8—C9—H9B	109.5
C1—N1—C5	121.74 (10)	H9A—C9—H9B	108.1
C1—N1—H1	115.3 (12)	C15—C10—C11	117.55 (12)
C5—N1—H1	119.6 (11)	C15—C10—C3	123.21 (11)
C2—C1—N1	120.07 (11)	C11—C10—C3	119.23 (12)
C2—C1—C9	123.28 (11)	C12—C11—C10	121.07 (15)
N1—C1—C9	116.64 (10)	C12—C11—H11	119.5
C1—C2—C6	119.74 (11)	C10—C11—H11	119.5
C1—C2—C3	119.91 (10)	C13—C12—C11	121.65 (14)
C6—C2—C3	120.28 (10)	C13—C12—H12	119.2
C4—C3—C2	109.36 (9)	C11—C12—H12	119.2
C4—C3—C10	113.30 (10)	C12—C13—C14	117.29 (13)
C2—C3—C10	109.80 (10)	C12—C13—C19	121.04 (14)
C4—C3—H3	108.1	C14—C13—C19	121.67 (15)
C2—C3—H3	108.1	C13—C14—C15	121.34 (13)
C10—C3—H3	108.1	C13—C14—H14	119.3
C5—C4—C16	120.58 (11)	C15—C14—H14	119.3
C5—C4—C3	120.53 (11)	C10—C15—C14	121.10 (12)
C16—C4—C3	118.82 (10)	C10—C15—H15	119.5
C4—C5—N1	119.18 (11)	C14—C15—H15	119.5
C4—C5—C18	127.33 (12)	O2—C16—O3	122.02 (12)
N1—C5—C18	113.49 (11)	O2—C16—C4	126.88 (12)
O1—C6—C2	121.26 (11)	O3—C16—C4	111.09 (10)
O1—C6—C7	120.20 (11)	O3—C17—H17A	109.5
C2—C6—C7	118.51 (11)	O3—C17—H17B	109.5
C6—C7—C8	112.63 (11)	H17A—C17—H17B	109.5
C6—C7—H7A	109.1	O3—C17—H17C	109.5
C8—C7—H7A	109.1	H17A—C17—H17C	109.5
C6—C7—H7B	109.1	H17B—C17—H17C	109.5
C8—C7—H7B	109.1	C5—C18—H18A	109.5
H7A—C7—H7B	107.8	C5—C18—H18B	109.5
C9—C8—C7	109.64 (11)	H18A—C18—H18B	109.5
C9—C8—H8A	109.7	C5—C18—H18C	109.5
C7—C8—H8A	109.7	H18A—C18—H18C	109.5
C9—C8—H8B	109.7	H18B—C18—H18C	109.5
C7—C8—H8B	109.7	C13—C19—H19A	109.5
H8A—C8—H8B	108.2	C13—C19—H19B	109.5
C1—C9—C8	110.55 (10)	H19A—C19—H19B	109.5
C1—C9—H9A	109.5	C13—C19—H19C	109.5
C8—C9—H9A	109.5	H19A—C19—H19C	109.5
C1—C9—H9B	109.5	H19B—C19—H19C	109.5
C5—N1—C1—C2	−16.61 (18)	C2—C6—C7—C8	22.84 (17)
C5—N1—C1—C9	162.02 (11)	C6—C7—C8—C9	−53.74 (15)
N1—C1—C2—C6	168.83 (11)	C2—C1—C9—C8	−22.58 (17)
C9—C1—C2—C6	−9.71 (18)	N1—C1—C9—C8	158.83 (11)
N1—C1—C2—C3	−8.18 (17)	C7—C8—C9—C1	52.88 (15)
C9—C1—C2—C3	173.28 (11)	C4—C3—C10—C15	−20.61 (16)
C1—C2—C3—C4	28.90 (15)	C2—C3—C10—C15	101.99 (13)
C6—C2—C3—C4	−148.09 (11)	C4—C3—C10—C11	160.92 (13)
C1—C2—C3—C10	−95.99 (13)	C2—C3—C10—C11	−76.49 (16)
C6—C2—C3—C10	87.01 (13)	C15—C10—C11—C12	−0.8 (3)
C2—C3—C4—C5	−29.11 (16)	C3—C10—C11—C12	177.79 (16)
C10—C3—C4—C5	93.73 (14)	C10—C11—C12—C13	0.3 (3)
C2—C3—C4—C16	153.75 (11)	C11—C12—C13—C14	0.4 (3)
C10—C3—C4—C16	−83.41 (14)	C11—C12—C13—C19	179.79 (19)
C16—C4—C5—N1	−174.45 (11)	C12—C13—C14—C15	−0.6 (2)
C3—C4—C5—N1	8.46 (18)	C19—C13—C14—C15	−179.97 (15)
C16—C4—C5—C18	6.4 (2)	C11—C10—C15—C14	0.6 (2)
C3—C4—C5—C18	−170.67 (13)	C3—C10—C15—C14	−177.92 (11)
C1—N1—C5—C4	16.47 (18)	C13—C14—C15—C10	0.1 (2)
C1—N1—C5—C18	−164.29 (12)	C17—O3—C16—O2	−2.07 (19)
C1—C2—C6—O1	−168.41 (12)	C17—O3—C16—C4	179.13 (11)
C3—C2—C6—O1	8.59 (18)	C5—C4—C16—O2	17.9 (2)
C1—C2—C6—C7	9.54 (18)	C3—C4—C16—O2	−164.94 (14)
C3—C2—C6—C7	−173.46 (11)	C5—C4—C16—O3	−163.35 (12)
O1—C6—C7—C8	−159.19 (12)	C3—C4—C16—O3	13.79 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1^i	0.854 (18)	2.017 (18)	2.8343 (15)	159.9 (16)

Symmetry code: (i) x, −y+1/2, z+1/2.