Ethyl 5-(5-oxo-2,3-di­hydro-5H-oxazolo­[2,3-a]­isoindol-9b-yl­methyl)-4-(2,5,5-tri­methyl-1,3-dioxan-2-yl)­isoxazole-3-carboxyl­ate: the product of a novel synthetic method

The title compound, C₂₄H₂₈N₂O₇, is the product of a novel synthetic procedure in which a highly functionalized heterocycle is formed. The crystal packing involves dimers, utilizing non-classical weak C—H...O interactions (ca 3.36–3.46 Å) and an antiparallel π–π interaction between two of the pseudo-aromatic isoxazole moieties. These dimers are associated into a three-dimensional network via further non-classical hydrogen bonding.

Key indicators

• Single-crystal X-ray study
• T = 85 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.048
• wR factor = 0.117
• Data-to-parameter ratio = 17.1

checkCIF/PLATON results

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PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
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   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 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
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Bruker, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Ethyl 5-(5-oxo-2,3-dihydro-5H-oxazolo[2,3-a]isoindol-9 b-ylmethyl)-4-(2,5,5-trimethyl- 1,3-dioxan-2-yl)isoxazole-3-carboxylate

Crystal data

C24H28N2O7	Dx = 1.352 Mg m^−3
Mr = 456.48	Melting point: 161 K
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 13.302 (3) Å	Cell parameters from 5056 reflections
b = 11.707 (2) Å	θ = 2.2–27.6°
c = 14.412 (3) Å	µ = 0.10 mm^−1
β = 91.76 (3)°	T = 85 K
V = 2243.3 (8) Å^3	Prism, colorless
Z = 4	0.24 × 0.14 × 0.13 mm
F(000) = 968

Data collection

Bruker–Siemens SMART APEX diffractometer	5153 independent reflections
Radiation source: normal-focus sealed tube	3773 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.045
Detector resolution: 8.3 pixels mm^-1	θmax = 27.6°, θmin = 2.1°
ω scans	h = −16→17
Absorption correction: multi-scan (SADABS; Bruker, 2001)	k = −15→15
Tmin = 0.976, Tmax = 0.987	l = −12→18
17860 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)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.117	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0555P)^2 + 0.2378P] where P = (Fo^2 + 2Fc^2)/3
5153 reflections	(Δ/σ)max = 0.001
302 parameters	Δρmax = 0.38 e Å^−3
0 restraints	Δρmin = −0.27 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
C1	0.42236 (13)	−0.12805 (14)	0.94438 (13)	0.0229 (4)
H1A	0.4353	−0.1767	0.8907	0.034*
H1B	0.4603	−0.1568	0.9988	0.034*
H1C	0.4435	−0.0497	0.9312	0.034*
C2	0.27446 (13)	−0.25078 (13)	0.98484 (12)	0.0206 (4)
H2A	0.2026	−0.2496	0.9977	0.031*
H2B	0.3122	−0.2804	1.0391	0.031*
H2C	0.2859	−0.3001	0.9312	0.031*
C3	0.30994 (12)	−0.12952 (13)	0.96370 (11)	0.0169 (3)
C4	0.24844 (12)	−0.08310 (13)	0.88125 (11)	0.0167 (3)
H4A	0.2634	−0.1279	0.8251	0.020*
H4B	0.1759	−0.0915	0.8931	0.020*
C5	0.25727 (11)	0.10745 (13)	0.94334 (11)	0.0144 (3)
C6	0.28664 (12)	−0.05190 (13)	1.04529 (11)	0.0167 (3)
H6A	0.2149	−0.0601	1.0604	0.020*
H6B	0.3277	−0.0756	1.1004	0.020*
C7	0.30754 (12)	0.21883 (13)	0.91901 (12)	0.0193 (4)
H7A	0.3006	0.2732	0.9701	0.029*
H7B	0.2756	0.2503	0.8624	0.029*
H7C	0.3790	0.2052	0.9087	0.029*
C8	0.14519 (12)	0.12222 (12)	0.95766 (11)	0.0137 (3)
C9	0.07099 (12)	0.12675 (12)	0.88443 (11)	0.0151 (3)
C10	0.08951 (12)	0.12252 (13)	0.78268 (11)	0.0171 (3)
C11	0.06909 (14)	0.01422 (15)	0.64452 (12)	0.0259 (4)
H11A	0.1406	−0.0055	0.6360	0.031*
H11B	0.0538	0.0855	0.6100	0.031*
C12	0.00249 (13)	−0.08065 (14)	0.60968 (12)	0.0224 (4)
H12A	0.0139	−0.1487	0.6482	0.034*
H12B	0.0181	−0.0982	0.5452	0.034*
H12C	−0.0680	−0.0571	0.6128	0.034*
C13	0.09111 (11)	0.13580 (12)	1.03517 (11)	0.0145 (3)
C14	0.11558 (12)	0.14001 (12)	1.13657 (11)	0.0158 (3)
H14A	0.1736	0.0890	1.1501	0.019*
H14B	0.0576	0.1097	1.1702	0.019*
C15	0.14094 (12)	0.25990 (13)	1.17436 (11)	0.0165 (3)
C16	0.05770 (12)	0.34719 (13)	1.16393 (11)	0.0181 (4)
C17	−0.04117 (13)	0.34283 (15)	1.19049 (12)	0.0231 (4)
H17	−0.0678	0.2760	1.2179	0.028*
C18	−0.10050 (14)	0.43947 (16)	1.17576 (13)	0.0285 (4)
H18	−0.1684	0.4388	1.1943	0.034*
C19	−0.06228 (15)	0.53676 (16)	1.13454 (14)	0.0311 (4)
H19	−0.1041	0.6020	1.1262	0.037*
C20	0.03600 (14)	0.53996 (15)	1.10547 (14)	0.0286 (4)
H20	0.0621	0.6058	1.0760	0.034*
C21	0.09507 (13)	0.44366 (13)	1.12088 (12)	0.0206 (4)
C22	0.20276 (13)	0.42523 (14)	1.10278 (13)	0.0231 (4)
C23	0.31897 (13)	0.28302 (14)	1.17617 (12)	0.0227 (4)
H23A	0.3594	0.3520	1.1912	0.027*
H23B	0.3595	0.2299	1.1391	0.027*
C24	0.28223 (13)	0.22509 (15)	1.26465 (13)	0.0251 (4)
H24A	0.2933	0.1416	1.2619	0.030*
H24B	0.3187	0.2557	1.3202	0.030*
N1	−0.02030 (10)	0.14061 (11)	0.91393 (9)	0.0190 (3)
N2	0.22451 (10)	0.31287 (11)	1.12711 (10)	0.0176 (3)
O1	0.27101 (8)	0.03538 (9)	0.86536 (7)	0.0168 (3)
O2	0.30748 (8)	0.06599 (9)	1.02434 (8)	0.0161 (2)
O3	0.04988 (9)	0.02951 (9)	0.74327 (8)	0.0202 (3)
O4	0.13522 (10)	0.19547 (10)	0.74326 (8)	0.0255 (3)
O5	0.17600 (8)	0.25034 (10)	1.26846 (8)	0.0216 (3)
O6	0.26416 (10)	0.49273 (10)	1.07445 (10)	0.0370 (4)
O7	−0.00808 (8)	0.14704 (9)	1.01126 (8)	0.0176 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0181 (9)	0.0240 (9)	0.0266 (10)	0.0038 (7)	0.0011 (7)	−0.0061 (7)
C2	0.0218 (9)	0.0159 (8)	0.0240 (10)	0.0031 (7)	0.0003 (7)	−0.0002 (7)
C3	0.0168 (8)	0.0170 (8)	0.0167 (9)	0.0018 (6)	−0.0006 (6)	−0.0013 (6)
C4	0.0175 (8)	0.0151 (7)	0.0175 (8)	−0.0002 (6)	0.0021 (6)	−0.0029 (6)
C5	0.0145 (8)	0.0155 (7)	0.0132 (8)	−0.0004 (6)	0.0012 (6)	0.0003 (6)
C6	0.0194 (8)	0.0142 (7)	0.0164 (9)	0.0013 (6)	−0.0011 (6)	0.0015 (6)
C7	0.0171 (8)	0.0194 (8)	0.0216 (9)	−0.0031 (6)	0.0039 (7)	0.0020 (7)
C8	0.0163 (8)	0.0093 (7)	0.0154 (8)	−0.0018 (6)	−0.0007 (6)	0.0005 (6)
C9	0.0166 (8)	0.0104 (7)	0.0183 (9)	−0.0020 (6)	−0.0001 (6)	0.0007 (6)
C10	0.0166 (8)	0.0180 (8)	0.0164 (9)	0.0003 (6)	−0.0028 (6)	0.0027 (6)
C11	0.0325 (10)	0.0323 (10)	0.0130 (9)	−0.0071 (8)	0.0007 (7)	−0.0009 (7)
C12	0.0249 (9)	0.0212 (8)	0.0208 (9)	0.0034 (7)	−0.0022 (7)	−0.0023 (7)
C13	0.0119 (8)	0.0106 (7)	0.0210 (9)	−0.0008 (6)	−0.0004 (6)	0.0004 (6)
C14	0.0175 (8)	0.0140 (7)	0.0162 (8)	−0.0001 (6)	0.0035 (6)	0.0004 (6)
C15	0.0183 (8)	0.0174 (8)	0.0138 (9)	−0.0014 (6)	0.0001 (6)	−0.0006 (6)
C16	0.0215 (9)	0.0176 (8)	0.0149 (9)	0.0012 (6)	−0.0018 (7)	−0.0063 (6)
C17	0.0236 (9)	0.0288 (9)	0.0172 (9)	0.0030 (7)	0.0024 (7)	−0.0029 (7)
C18	0.0235 (10)	0.0384 (11)	0.0235 (10)	0.0097 (8)	0.0004 (7)	−0.0087 (8)
C19	0.0331 (11)	0.0248 (9)	0.0347 (12)	0.0125 (8)	−0.0079 (9)	−0.0084 (8)
C20	0.0321 (11)	0.0185 (8)	0.0345 (11)	−0.0010 (7)	−0.0077 (8)	−0.0026 (8)
C21	0.0220 (9)	0.0164 (8)	0.0231 (10)	−0.0015 (6)	−0.0041 (7)	−0.0037 (7)
C22	0.0226 (9)	0.0176 (8)	0.0286 (10)	−0.0041 (7)	−0.0052 (7)	0.0000 (7)
C23	0.0168 (9)	0.0237 (9)	0.0273 (10)	−0.0007 (7)	−0.0034 (7)	−0.0046 (7)
C24	0.0213 (9)	0.0282 (9)	0.0252 (10)	0.0027 (7)	−0.0061 (7)	−0.0022 (8)
N1	0.0202 (7)	0.0196 (7)	0.0170 (8)	0.0000 (6)	−0.0017 (6)	0.0007 (6)
N2	0.0158 (7)	0.0155 (6)	0.0213 (8)	−0.0019 (5)	−0.0007 (6)	−0.0009 (6)
O1	0.0196 (6)	0.0158 (5)	0.0151 (6)	−0.0006 (4)	0.0028 (5)	−0.0006 (4)
O2	0.0157 (6)	0.0148 (5)	0.0176 (6)	−0.0002 (4)	−0.0028 (4)	−0.0005 (4)
O3	0.0244 (6)	0.0219 (6)	0.0143 (6)	−0.0069 (5)	0.0005 (5)	−0.0001 (5)
O4	0.0348 (7)	0.0235 (6)	0.0182 (7)	−0.0080 (5)	−0.0002 (5)	0.0061 (5)
O5	0.0225 (6)	0.0266 (6)	0.0155 (6)	0.0022 (5)	−0.0021 (5)	−0.0022 (5)
O6	0.0261 (7)	0.0244 (7)	0.0603 (10)	−0.0101 (5)	−0.0037 (7)	0.0111 (6)
O7	0.0152 (6)	0.0198 (6)	0.0178 (6)	−0.0004 (4)	0.0007 (4)	−0.0007 (5)

Geometric parameters (Å, º)

C1—C3	1.530 (2)	C12—H12A	0.9800
C1—H1A	0.9800	C12—H12B	0.9800
C1—H1B	0.9800	C12—H12C	0.9800
C1—H1C	0.9800	C13—O7	1.3599 (19)
C2—C3	1.530 (2)	C13—C14	1.488 (2)
C2—H2A	0.9800	C14—C15	1.539 (2)
C2—H2B	0.9800	C14—H14A	0.9900
C2—H2C	0.9800	C14—H14B	0.9900
C3—C4	1.522 (2)	C15—O5	1.425 (2)
C3—C6	1.525 (2)	C15—N2	1.460 (2)
C4—O1	1.4390 (18)	C15—C16	1.511 (2)
C4—H4A	0.9900	C16—C17	1.382 (2)
C4—H4B	0.9900	C16—C21	1.388 (2)
C5—O2	1.4130 (19)	C17—C18	1.392 (2)
C5—O1	1.4217 (18)	C17—H17	0.9500
C5—C7	1.512 (2)	C18—C19	1.388 (3)
C5—C8	1.521 (2)	C18—H18	0.9500
C6—O2	1.4416 (18)	C19—C20	1.385 (3)
C6—H6A	0.9900	C19—H19	0.9500
C6—H6B	0.9900	C20—C21	1.388 (2)
C7—H7A	0.9800	C20—H20	0.9500
C7—H7B	0.9800	C21—C22	1.480 (2)
C7—H7C	0.9800	C22—O6	1.216 (2)
C8—C13	1.356 (2)	C22—N2	1.390 (2)
C8—C9	1.424 (2)	C23—N2	1.465 (2)
C9—N1	1.309 (2)	C23—C24	1.537 (3)
C9—C10	1.495 (2)	C23—H23A	0.9900
C10—O4	1.2014 (19)	C23—H23B	0.9900
C10—O3	1.3296 (19)	C24—O5	1.446 (2)
C11—O3	1.465 (2)	C24—H24A	0.9900
C11—C12	1.498 (2)	C24—H24B	0.9900
C11—H11A	0.9900	N1—O7	1.4092 (17)
C11—H11B	0.9900
C3—C1—H1A	109.5	C11—C12—H12C	109.5
C3—C1—H1B	109.5	H12A—C12—H12C	109.5
H1A—C1—H1B	109.5	H12B—C12—H12C	109.5
C3—C1—H1C	109.5	C8—C13—O7	109.73 (14)
H1A—C1—H1C	109.5	C8—C13—C14	135.00 (15)
H1B—C1—H1C	109.5	O7—C13—C14	115.28 (13)
C3—C2—H2A	109.5	C13—C14—C15	114.62 (13)
C3—C2—H2B	109.5	C13—C14—H14A	108.6
H2A—C2—H2B	109.5	C15—C14—H14A	108.6
C3—C2—H2C	109.5	C13—C14—H14B	108.6
H2A—C2—H2C	109.5	C15—C14—H14B	108.6
H2B—C2—H2C	109.5	H14A—C14—H14B	107.6
C4—C3—C6	105.79 (13)	O5—C15—N2	104.22 (13)
C4—C3—C1	111.03 (14)	O5—C15—C16	111.43 (13)
C6—C3—C1	110.88 (14)	N2—C15—C16	103.44 (13)
C4—C3—C2	108.98 (13)	O5—C15—C14	109.08 (12)
C6—C3—C2	109.16 (13)	N2—C15—C14	112.59 (12)
C1—C3—C2	110.85 (13)	C16—C15—C14	115.44 (14)
O1—C4—C3	111.02 (13)	C17—C16—C21	120.72 (15)
O1—C4—H4A	109.4	C17—C16—C15	130.41 (15)
C3—C4—H4A	109.4	C21—C16—C15	108.87 (14)
O1—C4—H4B	109.4	C16—C17—C18	117.88 (17)
C3—C4—H4B	109.4	C16—C17—H17	121.1
H4A—C4—H4B	108.0	C18—C17—H17	121.1
O2—C5—O1	112.35 (12)	C19—C18—C17	121.25 (17)
O2—C5—C7	106.66 (13)	C19—C18—H18	119.4
O1—C5—C7	105.07 (12)	C17—C18—H18	119.4
O2—C5—C8	111.56 (12)	C20—C19—C18	120.86 (17)
O1—C5—C8	108.97 (13)	C20—C19—H19	119.6
C7—C5—C8	112.07 (12)	C18—C19—H19	119.6
O2—C6—C3	111.35 (13)	C19—C20—C21	117.66 (17)
O2—C6—H6A	109.4	C19—C20—H20	121.2
C3—C6—H6A	109.4	C21—C20—H20	121.2
O2—C6—H6B	109.4	C16—C21—C20	121.58 (16)
C3—C6—H6B	109.4	C16—C21—C22	108.78 (14)
H6A—C6—H6B	108.0	C20—C21—C22	129.53 (16)
C5—C7—H7A	109.5	O6—C22—N2	124.28 (16)
C5—C7—H7B	109.5	O6—C22—C21	128.91 (16)
H7A—C7—H7B	109.5	N2—C22—C21	106.79 (13)
C5—C7—H7C	109.5	N2—C23—C24	102.46 (13)
H7A—C7—H7C	109.5	N2—C23—H23A	111.3
H7B—C7—H7C	109.5	C24—C23—H23A	111.3
C13—C8—C9	103.48 (14)	N2—C23—H23B	111.3
C13—C8—C5	132.19 (15)	C24—C23—H23B	111.3
C9—C8—C5	124.32 (14)	H23A—C23—H23B	109.2
N1—C9—C8	113.13 (14)	O5—C24—C23	106.09 (14)
N1—C9—C10	120.34 (15)	O5—C24—H24A	110.5
C8—C9—C10	126.47 (14)	C23—C24—H24A	110.5
O4—C10—O3	125.45 (15)	O5—C24—H24B	110.5
O4—C10—C9	122.77 (15)	C23—C24—H24B	110.5
O3—C10—C9	111.78 (13)	H24A—C24—H24B	108.7
O3—C11—C12	107.30 (13)	C9—N1—O7	104.49 (13)
O3—C11—H11A	110.3	C22—N2—C15	111.36 (13)
C12—C11—H11A	110.3	C22—N2—C23	121.09 (13)
O3—C11—H11B	110.3	C15—N2—C23	109.13 (13)
C12—C11—H11B	110.3	C5—O1—C4	114.44 (11)
H11A—C11—H11B	108.5	C5—O2—C6	114.38 (12)
C11—C12—H12A	109.5	C10—O3—C11	115.88 (12)
C11—C12—H12B	109.5	C15—O5—C24	105.76 (12)
H12A—C12—H12B	109.5	C13—O7—N1	109.18 (12)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C14—H14B···O3^i	0.99	2.52	3.466 (2)	159
C12—H12C···O6^ii	0.98	2.40	3.357 (2)	164

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