Crystal strucutre of rac-methyl (11aR*,12S*,13R*,15aS*,15bS*)-11-oxo-11,11a,12,13-tetra-hydro-9H,15bH-13,15a-ep-oxy-isoindolo[1,2-c]pyrrolo[1,2-a][1,4]benzodiazepine-12-carboxyl-ate.

The title compound, C21H18N2O4, obtained as a racemate, contains a novel heterocyclic system, viz. isoindolo[1,2-c]pyrrolo-[1,2-a][1,4]benzodiazepine. The central diazepane ring has a distorted boat conformation with two phenyl-ene-fused and one methine C atom deviating by 0.931 (1), 0.887 (1) and 0.561 (1) Å, respectively, from the mean plane of the rest of the ring. The γ-lactone ring has an envelope conformation, with the C atom opposite to amide bond deviating by 0.355 (1) Å from its plane. In the crystal, mol-ecules form centrosymmetric dimers through pairs of C-H⋯O hydrogen bonds.

Related literature

For the synthesis of pyrrolo­[1,2-a][1,4]benzodiazepine, see: Raines et al. (1976 ▶). For reviews on intra­molecular cyclo­addition reactions of α,β-unsaturated acid anhydrides to furfuryl­amines (IMDAF reactions), see: Vogel et al. (1999 ▶); Zubkov et al. (2005 ▶). For related compounds, see: Zubkov et al. (2009 ▶, 2014 ▶); Zubkov, Galeev et al. (2010 ▶); Zubkov, Zaitsev et al. (2010 ▶); Zaytsev et al. (2012 ▶, 2013 ▶); Toze et al. (2011 ▶).

Experimental

Crystal data

C21H18N2O4

M = 362.37

Monoclinic,

a = 8.1565 (3) Å

b = 14.2567 (5) Å

c = 14.6664 (5) Å

β = 98.210 (1)°

V = 1688.00 (10) Å3

Z = 4

Mo Kα radiation

μ = 0.10 mm−1

T = 100 K

0.30 × 0.30 × 0.30 mm

Data collection

Bruker APEX DUO CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2003 ▶) T min = 0.971, T max = 0.971

25733 measured reflections

6162 independent reflections

5097 reflections with I > 2σ(I)

R int = 0.029

Refinement

R[F 2 > 2σ(F 2)] = 0.043

wR(F 2) = 0.119

S = 1.00

6162 reflections

245 parameters

H-atom parameters constrained

Δρmax = 0.47 e Å−3

Δρmin = −0.27 e Å−3

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2001 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536814023344/ld2132sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814023344/ld2132Isup2.hkl

Click here for additional data file.

H H c a . DOI: 10.1107/S1600536814023344/ld2132fig1.tif

Synthesis of methyl 11-oxo-11,11a,12,13-tetra­hydro-9H,15b-H-13,15a-ep­oxy­isoindolo[1,2c]pyrrolo­[1,2a][1,4]benzodiazepine-12-carboxyl­ate.

Click here for additional data file.

. DOI: 10.1107/S1600536814023344/ld2132fig2.tif

Mol­ecular structure of (I). Displacement ellipsoids are shown at the 50% probability level. H atoms are depicted as small spheres of arbitrary radius.

Click here for additional data file.

I a . DOI: 10.1107/S1600536814023344/ld2132fig3.tif

A portion of crystal packing of I along the crystallographic a axis demonstrating the centrosymmetric H-bonded dimers. Only hydrogen atoms at the asymmetric centers are shown. Dashed lines indicate the weak inter­molecular C—H⋯O n class="Chemical">hydrogen bonds.

CCDC reference: 903490

Additional supporting information: crystallographic information; 3D view; checkCIF report

C21H18N2O4	F(000) = 760
Mr = 362.37	Dx = 1.426 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 8798 reflections
a = 8.1565 (3) Å	θ = 2.5–32.6°
b = 14.2567 (5) Å	µ = 0.10 mm−1
c = 14.6664 (5) Å	T = 100 K
β = 98.210 (1)°	Prism, yellow
V = 1688.00 (10) Å3	0.30 × 0.30 × 0.30 mm
Z = 4

Bruker APEX DUO CCD diffractometer	6162 independent reflections
Radiation source: fine-focus sealed tube	5097 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
φ and ω scans	θmax = 32.6°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 2003)	h = −12→12
Tmin = 0.971, Tmax = 0.971	k = −21→21
25733 measured reflections	l = −22→22

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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.119	H-atom parameters constrained
S = 1.00	w = 1/[σ2(Fo2) + (0.0646P)2 + 0.565P] where P = (Fo2 + 2Fc2)/3
6162 reflections	(Δ/σ)max < 0.001
245 parameters	Δρmax = 0.47 e Å−3
0 restraints	Δρmin = −0.27 e Å−3

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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	0.27309 (9)	0.45215 (5)	0.53193 (5)	0.01848 (14)
O2	0.47579 (12)	0.27298 (6)	0.63472 (6)	0.02842 (18)
O3	0.60524 (10)	0.32277 (5)	0.51730 (5)	0.02255 (16)
C1	0.31059 (13)	0.53225 (7)	0.90588 (6)	0.01946 (18)
H1	0.4020	0.4912	0.9216	0.023*
C2	0.19108 (14)	0.55791 (9)	0.96356 (7)	0.0242 (2)
H2	0.1883	0.5366	1.0247	0.029*
C3	0.08144 (14)	0.61843 (8)	0.91546 (7)	0.0228 (2)
H3	−0.0107	0.6469	0.9374	0.027*
N4	0.12777 (10)	0.63120 (6)	0.82896 (6)	0.01710 (16)
C4A	0.04475 (12)	0.68950 (7)	0.75861 (7)	0.01735 (17)
C5	−0.02093 (13)	0.77501 (7)	0.78280 (8)	0.0232 (2)
H5	−0.0068	0.7944	0.8454	0.028*
C6	−0.10691 (14)	0.83162 (8)	0.71507 (9)	0.0274 (2)
H6	−0.1560	0.8884	0.7317	0.033*
C7	−0.12110 (15)	0.80554 (8)	0.62343 (9)	0.0279 (2)
H7	−0.1745	0.8460	0.5769	0.033*
C8	−0.05706 (14)	0.71985 (8)	0.59930 (8)	0.0227 (2)
H8	−0.0687	0.7021	0.5363	0.027*
C8A	0.02398 (12)	0.65967 (7)	0.66631 (7)	0.01659 (17)
C9	0.07294 (11)	0.56233 (7)	0.63935 (6)	0.01498 (16)
H9A	0.0174	0.5155	0.6743	0.018*
H9B	0.0334	0.5525	0.5730	0.018*
N10	0.25065 (10)	0.54661 (6)	0.65654 (5)	0.01399 (14)
C11	0.33580 (12)	0.49482 (6)	0.60081 (6)	0.01406 (16)
C11A	0.51928 (11)	0.50475 (6)	0.63808 (6)	0.01349 (15)
H11A	0.5705	0.5566	0.6059	0.016*
C12	0.63419 (12)	0.41731 (6)	0.64878 (6)	0.01520 (16)
H12	0.7414	0.4322	0.6264	0.018*
C13	0.66222 (12)	0.40784 (7)	0.75634 (6)	0.01691 (17)
H13	0.6992	0.3444	0.7801	0.020*
C14	0.77432 (12)	0.48870 (8)	0.79392 (7)	0.01889 (18)
H14	0.8884	0.4852	0.8186	0.023*
C15	0.67943 (12)	0.56536 (7)	0.78501 (6)	0.01747 (17)
H15	0.7105	0.6277	0.8026	0.021*
C15A	0.51170 (11)	0.53094 (6)	0.74072 (6)	0.01330 (15)
C15B	0.35216 (11)	0.58535 (6)	0.73907 (6)	0.01326 (15)
H15B	0.3746	0.6530	0.7277	0.016*
C15C	0.26875 (12)	0.57808 (7)	0.82316 (6)	0.01505 (16)
O16	0.50407 (9)	0.43775 (5)	0.77891 (5)	0.01577 (13)
C16	0.55961 (12)	0.32965 (7)	0.60170 (7)	0.01805 (18)
C17	0.53752 (19)	0.24502 (8)	0.46127 (9)	0.0329 (3)
H17A	0.6124	0.2289	0.4170	0.049*
H17B	0.4290	0.2625	0.4280	0.049*
H17C	0.5252	0.1908	0.5008	0.049*

	U11	U22	U33	U12	U13	U23
O1	0.0207 (3)	0.0205 (3)	0.0142 (3)	0.0013 (3)	0.0025 (2)	−0.0047 (2)
O2	0.0349 (5)	0.0188 (4)	0.0335 (4)	−0.0061 (3)	0.0117 (4)	−0.0013 (3)
O3	0.0306 (4)	0.0187 (3)	0.0186 (3)	0.0031 (3)	0.0043 (3)	−0.0035 (3)
C1	0.0229 (4)	0.0227 (4)	0.0130 (4)	−0.0056 (4)	0.0032 (3)	−0.0013 (3)
C2	0.0276 (5)	0.0331 (6)	0.0132 (4)	−0.0092 (4)	0.0074 (4)	−0.0036 (4)
C3	0.0234 (5)	0.0315 (5)	0.0158 (4)	−0.0079 (4)	0.0102 (4)	−0.0082 (4)
N4	0.0178 (4)	0.0196 (4)	0.0152 (3)	−0.0034 (3)	0.0069 (3)	−0.0047 (3)
C4A	0.0155 (4)	0.0161 (4)	0.0219 (4)	−0.0024 (3)	0.0076 (3)	−0.0039 (3)
C5	0.0196 (4)	0.0188 (4)	0.0329 (5)	−0.0022 (3)	0.0096 (4)	−0.0094 (4)
C6	0.0217 (5)	0.0158 (4)	0.0462 (7)	0.0012 (4)	0.0105 (5)	−0.0055 (4)
C7	0.0257 (5)	0.0190 (5)	0.0397 (6)	0.0049 (4)	0.0073 (5)	0.0042 (4)
C8	0.0232 (5)	0.0204 (4)	0.0254 (5)	0.0052 (4)	0.0066 (4)	0.0033 (4)
C8A	0.0159 (4)	0.0150 (4)	0.0200 (4)	0.0007 (3)	0.0065 (3)	−0.0004 (3)
C9	0.0147 (4)	0.0152 (4)	0.0152 (4)	0.0014 (3)	0.0023 (3)	−0.0014 (3)
N10	0.0146 (3)	0.0158 (3)	0.0117 (3)	0.0013 (3)	0.0023 (2)	−0.0021 (3)
C11	0.0170 (4)	0.0137 (4)	0.0121 (3)	0.0013 (3)	0.0043 (3)	0.0009 (3)
C11A	0.0152 (4)	0.0133 (4)	0.0127 (3)	0.0005 (3)	0.0043 (3)	0.0005 (3)
C12	0.0164 (4)	0.0146 (4)	0.0151 (4)	0.0012 (3)	0.0041 (3)	0.0008 (3)
C13	0.0168 (4)	0.0183 (4)	0.0161 (4)	0.0022 (3)	0.0036 (3)	0.0033 (3)
C14	0.0164 (4)	0.0258 (5)	0.0144 (4)	−0.0008 (3)	0.0022 (3)	0.0004 (3)
C15	0.0162 (4)	0.0215 (4)	0.0150 (4)	−0.0044 (3)	0.0034 (3)	−0.0015 (3)
C15A	0.0151 (4)	0.0130 (4)	0.0123 (3)	−0.0013 (3)	0.0036 (3)	0.0006 (3)
C15B	0.0154 (4)	0.0133 (3)	0.0115 (3)	−0.0017 (3)	0.0035 (3)	−0.0015 (3)
C15C	0.0168 (4)	0.0158 (4)	0.0132 (4)	−0.0040 (3)	0.0046 (3)	−0.0029 (3)
O16	0.0173 (3)	0.0152 (3)	0.0157 (3)	0.0002 (2)	0.0054 (2)	0.0037 (2)
C16	0.0198 (4)	0.0150 (4)	0.0195 (4)	0.0041 (3)	0.0036 (3)	−0.0004 (3)
C17	0.0497 (8)	0.0209 (5)	0.0256 (5)	0.0033 (5)	−0.0037 (5)	−0.0070 (4)

O1—C11	1.2267 (11)	C9—H9A	0.9900
O2—C16	1.2039 (13)	C9—H9B	0.9900
O3—C16	1.3460 (12)	N10—C11	1.3629 (11)
O3—C17	1.4420 (14)	N10—C15B	1.4729 (11)
C1—C15C	1.3773 (13)	C11—C11A	1.5247 (13)
C1—C2	1.4266 (15)	C11A—C12	1.5541 (13)
C1—H1	0.9500	C11A—C15A	1.5607 (13)
C2—C3	1.3644 (17)	C11A—H11A	1.0000
C2—H2	0.9500	C12—C16	1.5129 (14)
C3—N4	1.3866 (12)	C12—C13	1.5672 (13)
C3—H3	0.9500	C12—H12	1.0000
N4—C15C	1.3896 (13)	C13—O16	1.4413 (12)
N4—C4A	1.4192 (13)	C13—C14	1.5247 (14)
C4A—C5	1.3976 (14)	C13—H13	1.0000
C4A—C8A	1.4059 (13)	C14—C15	1.3349 (15)
C5—C6	1.3897 (17)	C14—H14	0.9500
C5—H5	0.9500	C15—C15A	1.5102 (13)
C6—C7	1.3834 (18)	C15—H15	0.9500
C6—H6	0.9500	C15A—O16	1.4466 (11)
C7—C8	1.3941 (15)	C15A—C15B	1.5122 (13)
C7—H7	0.9500	C15B—C15C	1.4948 (12)
C8—C8A	1.3976 (14)	C15B—H15B	1.0000
C8—H8	0.9500	C17—H17A	0.9800
C8A—C9	1.5123 (13)	C17—H17B	0.9800
C9—N10	1.4528 (12)	C17—H17C	0.9800
C16—O3—C17	116.50 (9)	C11—C11A—H11A	110.8
C15C—C1—C2	107.24 (10)	C12—C11A—H11A	110.8
C15C—C1—H1	126.4	C15A—C11A—H11A	110.8
C2—C1—H1	126.4	C16—C12—C11A	114.78 (8)
C3—C2—C1	107.97 (9)	C16—C12—C13	112.31 (8)
C3—C2—H2	126.0	C11A—C12—C13	99.79 (7)
C1—C2—H2	126.0	C16—C12—H12	109.9
C2—C3—N4	108.18 (9)	C11A—C12—H12	109.9
C2—C3—H3	125.9	C13—C12—H12	109.9
N4—C3—H3	125.9	O16—C13—C14	101.74 (8)
C3—N4—C15C	108.69 (9)	O16—C13—C12	101.47 (7)
C3—N4—C4A	125.31 (9)	C14—C13—C12	107.01 (8)
C15C—N4—C4A	126.00 (8)	O16—C13—H13	115.0
C5—C4A—C8A	120.69 (10)	C14—C13—H13	115.0
C5—C4A—N4	119.12 (9)	C12—C13—H13	115.0
C8A—C4A—N4	120.15 (8)	C15—C14—C13	105.92 (8)
C6—C5—C4A	119.85 (10)	C15—C14—H14	127.0
C6—C5—H5	120.1	C13—C14—H14	127.0
C4A—C5—H5	120.1	C14—C15—C15A	104.65 (8)
C7—C6—C5	120.14 (10)	C14—C15—H15	127.7
C7—C6—H6	119.9	C15A—C15—H15	127.7
C5—C6—H6	119.9	O16—C15A—C15	102.61 (7)
C6—C7—C8	119.99 (11)	O16—C15A—C15B	113.13 (7)
C6—C7—H7	120.0	C15—C15A—C15B	124.39 (8)
C8—C7—H7	120.0	O16—C15A—C11A	99.42 (7)
C7—C8—C8A	121.07 (10)	C15—C15A—C11A	109.54 (7)
C7—C8—H8	119.5	C15B—C15A—C11A	105.06 (7)
C8A—C8—H8	119.5	N10—C15B—C15C	112.54 (7)
C8—C8A—C4A	118.12 (9)	N10—C15B—C15A	101.67 (7)
C8—C8A—C9	119.70 (9)	C15C—C15B—C15A	116.31 (8)
C4A—C8A—C9	121.96 (9)	N10—C15B—H15B	108.7
N10—C9—C8A	112.98 (8)	C15C—C15B—H15B	108.7
N10—C9—H9A	109.0	C15A—C15B—H15B	108.7
C8A—C9—H9A	109.0	C1—C15C—N4	107.93 (8)
N10—C9—H9B	109.0	C1—C15C—C15B	132.45 (9)
C8A—C9—H9B	109.0	N4—C15C—C15B	119.39 (8)
H9A—C9—H9B	107.8	C13—O16—C15A	95.36 (7)
C11—N10—C9	124.11 (8)	O2—C16—O3	124.65 (10)
C11—N10—C15B	114.91 (8)	O2—C16—C12	125.82 (9)
C9—N10—C15B	120.97 (7)	O3—C16—C12	109.51 (8)
O1—C11—N10	125.05 (9)	O3—C17—H17A	109.5
O1—C11—C11A	127.86 (8)	O3—C17—H17B	109.5
N10—C11—C11A	107.03 (7)	H17A—C17—H17B	109.5
C11—C11A—C12	120.57 (8)	O3—C17—H17C	109.5
C11—C11A—C15A	101.30 (7)	H17A—C17—H17C	109.5
C12—C11A—C15A	101.58 (7)	H17B—C17—H17C	109.5
C15C—C1—C2—C3	−0.39 (12)	C13—C14—C15—C15A	−0.95 (10)
C1—C2—C3—N4	0.35 (12)	C14—C15—C15A—O16	33.34 (9)
C2—C3—N4—C15C	−0.19 (12)	C14—C15—C15A—C15B	163.20 (8)
C2—C3—N4—C4A	−179.84 (9)	C14—C15—C15A—C11A	−71.57 (9)
C3—N4—C4A—C5	37.78 (14)	C11—C11A—C15A—O16	85.68 (7)
C15C—N4—C4A—C5	−141.80 (10)	C12—C11A—C15A—O16	−39.10 (8)
C3—N4—C4A—C8A	−139.92 (10)	C11—C11A—C15A—C15	−167.24 (7)
C15C—N4—C4A—C8A	40.50 (14)	C12—C11A—C15A—C15	67.98 (9)
C8A—C4A—C5—C6	−0.39 (15)	C11—C11A—C15A—C15B	−31.51 (8)
N4—C4A—C5—C6	−178.07 (9)	C12—C11A—C15A—C15B	−156.29 (7)
C4A—C5—C6—C7	−2.93 (17)	C11—N10—C15B—C15C	−138.43 (8)
C5—C6—C7—C8	3.57 (18)	C9—N10—C15B—C15C	40.32 (11)
C6—C7—C8—C8A	−0.88 (17)	C11—N10—C15B—C15A	−13.28 (10)
C7—C8—C8A—C4A	−2.36 (16)	C9—N10—C15B—C15A	165.47 (8)
C7—C8—C8A—C9	172.37 (10)	O16—C15A—C15B—N10	−80.04 (8)
C5—C4A—C8A—C8	2.98 (14)	C15—C15A—C15B—N10	154.51 (8)
N4—C4A—C8A—C8	−179.36 (9)	C11A—C15A—C15B—N10	27.37 (8)
C5—C4A—C8A—C9	−171.61 (9)	O16—C15A—C15B—C15C	42.57 (10)
N4—C4A—C8A—C9	6.05 (14)	C15—C15A—C15B—C15C	−82.88 (11)
C8—C8A—C9—N10	118.64 (10)	C11A—C15A—C15B—C15C	149.98 (8)
C4A—C8A—C9—N10	−66.84 (11)	C2—C1—C15C—N4	0.27 (11)
C8A—C9—N10—C11	−143.31 (9)	C2—C1—C15C—C15B	174.54 (10)
C8A—C9—N10—C15B	38.06 (11)	C3—N4—C15C—C1	−0.05 (11)
C9—N10—C11—O1	−3.19 (15)	C4A—N4—C15C—C1	179.59 (9)
C15B—N10—C11—O1	175.52 (9)	C3—N4—C15C—C15B	−175.20 (8)
C9—N10—C11—C11A	174.16 (8)	C4A—N4—C15C—C15B	4.44 (14)
C15B—N10—C11—C11A	−7.13 (10)	N10—C15B—C15C—C1	118.64 (11)
O1—C11—C11A—C12	−48.29 (13)	C15A—C15B—C15C—C1	1.93 (15)
N10—C11—C11A—C12	134.46 (8)	N10—C15B—C15C—N4	−67.62 (11)
O1—C11—C11A—C15A	−159.13 (9)	C15A—C15B—C15C—N4	175.67 (8)
N10—C11—C11A—C15A	23.61 (9)	C14—C13—O16—C15A	49.73 (8)
C11—C11A—C12—C16	12.35 (12)	C12—C13—O16—C15A	−60.58 (8)
C15A—C11A—C12—C16	123.04 (8)	C15—C15A—O16—C13	−51.04 (8)
C11—C11A—C12—C13	−107.91 (9)	C15B—C15A—O16—C13	172.50 (7)
C15A—C11A—C12—C13	2.78 (8)	C11A—C15A—O16—C13	61.58 (7)
C16—C12—C13—O16	−87.41 (9)	C17—O3—C16—O2	4.70 (15)
C11A—C12—C13—O16	34.64 (8)	C17—O3—C16—C12	−177.05 (9)
C16—C12—C13—C14	166.38 (8)	C11A—C12—C16—O2	−87.26 (12)
C11A—C12—C13—C14	−71.58 (9)	C13—C12—C16—O2	25.82 (14)
O16—C13—C14—C15	−31.71 (9)	C11A—C12—C16—O3	94.52 (9)
C12—C13—C14—C15	74.32 (9)	C13—C12—C16—O3	−152.41 (8)

D—H···A	D—H	H···A	D···A	D—H···A
C11A—H11A···O1i	1.00	2.54	3.2663 (12)	129

Table 1

Hydrogen-bond geometry (, )

DHA	DH	HA	D A	DHA
C11AH11AO1i	1.00	2.54	3.2663(12)	129

Symmetry code: (i) .