(Z)-1,3,4a-Trimethyl-5,5-diphenyl-6-oxa-1,3-diaza-bicyclo-[4.2.0]octane-2,4-dione.

The title compound, C(20)H(20)N(2)O(3), is a head-to-tail oxetane, one of the regioisomers obtained by the the Paternó-Büchi reaction of 1,3-dimethyl-thymine with benzophenone. The oxetane ring is folded, the dihedral angle between the C-O-C and C-C-C planes being 14.4 (2)°. The dihedral angle between the two phenyl rings is 64.3 (2)°. The pyrimidine ring adopts a boat conformation. The crystal structure involves weak C-H⋯O hydrogen bonds.

Related literature

For related literature, see: Hei et al. (2005 ▶); Prakash et al. (1997 ▶).

Experimental

Crystal data

C20H20N2O3

M = 336.38

Monoclinic,

a = 8.1341 (7) Å

b = 9.1004 (13) Å

c = 23.485 (2) Å

β = 97.334 (2)°

V = 1724.2 (3) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 298 (2) K

0.45 × 0.41 × 0.18 mm

Data collection

Bruker SMART diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.962, T max = 0.984

8774 measured reflections

3039 independent reflections

1818 reflections with I > 2σ(I)

R int = 0.036

Refinement

R[F 2 > 2σ(F 2)] = 0.044

wR(F 2) = 0.117

S = 1.01

3039 reflections

226 parameters

H-atom parameters constrained

Δρmax = 0.20 e Å−3

Δρmin = −0.18 e Å−3

Data collection: SMART (Siemens, 1996 ▶); cell refinement: SAINT (Siemens, 1996 ▶); 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 datablocks I, global. DOI: 10.1107/S1600536808006557/wn2239sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808006557/wn2239Isup2.hkl

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

C20H20N2O3	F000 = 712
Mr = 336.38	Dx = 1.296 Mg m−3
Monoclinic, P21/n	Mo Kα radiation λ = 0.71073 Å
a = 8.1341 (7) Å	Cell parameters from 1952 reflections
b = 9.1004 (13) Å	θ = 2.4–22.1º
c = 23.485 (2) Å	µ = 0.09 mm−1
β = 97.334 (2)º	T = 298 (2) K
V = 1724.2 (3) Å3	Block, colorless
Z = 4	0.45 × 0.41 × 0.18 mm

Bruker SMART diffractometer	3039 independent reflections
Radiation source: fine-focus sealed tube	1818 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.036
T = 298(2) K	θmax = 25.0º
φ and ω scans	θmin = 1.8º
Absorption correction: multi-scan(SADABS; Sheldrick, 1996)	h = −9→9
Tmin = 0.962, Tmax = 0.984	k = −10→10
8774 measured reflections	l = −24→27

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)] = 0.044	H-atom parameters constrained
wR(F2) = 0.117	w = 1/[σ2(Fo2) + (0.038P)2 + 0.7238P] where P = (Fo2 + 2Fc2)/3
S = 1.01	(Δ/σ)max < 0.001
3039 reflections	Δρmax = 0.20 e Å−3
226 parameters	Δρmin = −0.18 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

	x	y	z	Uiso*/Ueq
N1	1.2692 (2)	0.5663 (2)	0.21196 (8)	0.0491 (5)
N2	1.2831 (2)	0.6885 (2)	0.12510 (8)	0.0492 (5)
O1	0.97763 (19)	0.60800 (17)	0.19685 (6)	0.0469 (4)
O2	1.4490 (2)	0.7527 (2)	0.20642 (8)	0.0750 (6)
O3	1.1732 (2)	0.5833 (2)	0.04218 (7)	0.0625 (5)
C1	0.9036 (3)	0.5849 (2)	0.13794 (8)	0.0379 (5)
C2	1.0673 (3)	0.4991 (2)	0.12589 (9)	0.0380 (5)
C3	1.1126 (3)	0.5076 (3)	0.19078 (9)	0.0427 (6)
H3	1.0949	0.4127	0.2088	0.051*
C4	1.3391 (3)	0.6743 (3)	0.18356 (11)	0.0503 (6)
C5	1.1782 (3)	0.5906 (3)	0.09400 (10)	0.0440 (6)
C6	0.7544 (3)	0.4834 (2)	0.13563 (9)	0.0398 (6)
C7	0.7166 (3)	0.4145 (3)	0.18451 (11)	0.0555 (7)
H7	0.7781	0.4358	0.2197	0.067*
C8	0.5890 (4)	0.3147 (3)	0.18183 (13)	0.0654 (8)
H8	0.5646	0.2695	0.2153	0.079*
C9	0.4977 (3)	0.2812 (3)	0.13056 (13)	0.0617 (8)
H9	0.4128	0.2124	0.1289	0.074*
C10	0.5325 (3)	0.3502 (3)	0.08148 (12)	0.0580 (7)
H10	0.4701	0.3289	0.0465	0.070*
C11	0.6592 (3)	0.4506 (3)	0.08398 (10)	0.0481 (6)
H11	0.6815	0.4971	0.0506	0.058*
C12	0.8626 (3)	0.7299 (2)	0.10882 (9)	0.0385 (6)
C13	0.8285 (3)	0.8494 (3)	0.14167 (11)	0.0505 (6)
H13	0.8336	0.8392	0.1813	0.061*
C14	0.7872 (4)	0.9835 (3)	0.11655 (14)	0.0673 (8)
H14	0.7645	1.0629	0.1392	0.081*
C15	0.7794 (4)	0.9999 (3)	0.05856 (14)	0.0727 (9)
H15	0.7523	1.0906	0.0417	0.087*
C16	0.8116 (4)	0.8830 (3)	0.02531 (12)	0.0666 (8)
H16	0.8061	0.8942	−0.0142	0.080*
C17	0.8520 (3)	0.7485 (3)	0.05001 (10)	0.0504 (6)
H17	0.8724	0.6693	0.0269	0.060*
C18	1.0451 (3)	0.3473 (3)	0.09951 (10)	0.0503 (6)
H18A	0.9886	0.3552	0.0612	0.075*
H18B	0.9809	0.2877	0.1222	0.075*
H18C	1.1517	0.3029	0.0985	0.075*
C19	1.3263 (4)	0.5493 (3)	0.27297 (11)	0.0783 (9)
H19A	1.4432	0.5683	0.2799	0.117*
H19B	1.3046	0.4508	0.2847	0.117*
H19C	1.2686	0.6175	0.2945	0.117*
C20	1.3705 (4)	0.7944 (3)	0.09317 (13)	0.0803 (10)
H20A	1.4539	0.7445	0.0751	0.121*
H20B	1.4218	0.8676	0.1190	0.121*
H20C	1.2931	0.8408	0.0644	0.121*

	U11	U22	U33	U12	U13	U23
N1	0.0490 (13)	0.0549 (13)	0.0392 (12)	0.0034 (11)	−0.0110 (9)	−0.0031 (10)
N2	0.0448 (12)	0.0524 (13)	0.0499 (13)	−0.0048 (10)	0.0035 (10)	−0.0005 (10)
O1	0.0509 (10)	0.0554 (11)	0.0329 (9)	0.0088 (8)	−0.0009 (7)	−0.0072 (7)
O2	0.0666 (13)	0.0819 (14)	0.0730 (13)	−0.0225 (12)	−0.0044 (11)	−0.0256 (11)
O3	0.0560 (12)	0.0921 (14)	0.0402 (11)	−0.0015 (10)	0.0092 (8)	−0.0015 (9)
C1	0.0403 (14)	0.0433 (14)	0.0290 (12)	0.0050 (11)	0.0004 (10)	−0.0041 (10)
C2	0.0387 (13)	0.0403 (13)	0.0336 (12)	0.0042 (11)	−0.0008 (10)	−0.0043 (10)
C3	0.0467 (15)	0.0395 (14)	0.0402 (14)	0.0043 (12)	−0.0011 (11)	−0.0030 (11)
C4	0.0450 (15)	0.0526 (17)	0.0519 (16)	0.0041 (13)	0.0012 (13)	−0.0122 (13)
C5	0.0377 (14)	0.0522 (16)	0.0414 (15)	0.0069 (12)	0.0024 (11)	−0.0021 (12)
C6	0.0379 (13)	0.0414 (14)	0.0405 (14)	0.0063 (11)	0.0067 (11)	0.0006 (11)
C7	0.0573 (17)	0.0665 (18)	0.0442 (15)	−0.0029 (15)	0.0119 (12)	0.0020 (13)
C8	0.0656 (19)	0.070 (2)	0.065 (2)	−0.0033 (16)	0.0253 (16)	0.0127 (15)
C9	0.0438 (16)	0.0573 (18)	0.085 (2)	−0.0021 (14)	0.0134 (15)	0.0074 (16)
C10	0.0402 (15)	0.0623 (18)	0.0680 (19)	−0.0026 (14)	−0.0062 (13)	0.0037 (15)
C11	0.0447 (15)	0.0519 (16)	0.0467 (15)	−0.0002 (13)	0.0015 (12)	0.0076 (12)
C12	0.0324 (13)	0.0391 (14)	0.0434 (14)	0.0010 (10)	0.0027 (10)	−0.0035 (11)
C13	0.0477 (15)	0.0505 (16)	0.0512 (15)	0.0059 (13)	−0.0016 (12)	−0.0098 (13)
C14	0.073 (2)	0.0418 (16)	0.083 (2)	0.0119 (14)	−0.0031 (16)	−0.0150 (15)
C15	0.087 (2)	0.0434 (17)	0.083 (2)	0.0064 (15)	−0.0078 (18)	0.0103 (16)
C16	0.089 (2)	0.0519 (18)	0.0564 (17)	0.0058 (16)	−0.0001 (15)	0.0085 (14)
C17	0.0587 (17)	0.0438 (15)	0.0483 (16)	0.0068 (13)	0.0059 (12)	0.0010 (12)
C18	0.0462 (15)	0.0501 (15)	0.0524 (15)	0.0065 (12)	−0.0026 (12)	−0.0129 (12)
C19	0.082 (2)	0.095 (2)	0.0493 (17)	−0.0024 (19)	−0.0221 (15)	0.0001 (16)
C20	0.078 (2)	0.082 (2)	0.082 (2)	−0.0240 (18)	0.0150 (18)	0.0105 (17)

N1—C4	1.353 (3)	C9—H9	0.9300
N1—C3	1.412 (3)	C10—C11	1.373 (3)
N1—C19	1.457 (3)	C10—H10	0.9300
N2—C5	1.377 (3)	C11—H11	0.9300
N2—C4	1.396 (3)	C12—C13	1.381 (3)
N2—C20	1.460 (3)	C12—C17	1.383 (3)
O1—C3	1.450 (3)	C13—C14	1.379 (4)
O1—C1	1.452 (2)	C13—H13	0.9300
O2—C4	1.214 (3)	C14—C15	1.364 (4)
O3—C5	1.214 (3)	C14—H14	0.9300
C1—C12	1.504 (3)	C15—C16	1.365 (4)
C1—C6	1.521 (3)	C15—H15	0.9300
C1—C2	1.600 (3)	C16—C17	1.376 (3)
C2—C5	1.497 (3)	C16—H16	0.9300
C2—C18	1.515 (3)	C17—H17	0.9300
C2—C3	1.523 (3)	C18—H18A	0.9600
C3—H3	0.9800	C18—H18B	0.9600
C6—C7	1.376 (3)	C18—H18C	0.9600
C6—C11	1.386 (3)	C19—H19A	0.9600
C7—C8	1.375 (4)	C19—H19B	0.9600
C7—H7	0.9300	C19—H19C	0.9600
C8—C9	1.366 (4)	C20—H20A	0.9600
C8—H8	0.9300	C20—H20B	0.9600
C9—C10	1.373 (4)	C20—H20C	0.9600
C4—N1—C3	121.2 (2)	C11—C10—C9	120.2 (3)
C4—N1—C19	117.4 (2)	C11—C10—H10	119.9
C3—N1—C19	117.8 (2)	C9—C10—H10	119.9
C5—N2—C4	124.3 (2)	C10—C11—C6	120.9 (2)
C5—N2—C20	117.6 (2)	C10—C11—H11	119.6
C4—N2—C20	116.6 (2)	C6—C11—H11	119.6
C3—O1—C1	92.41 (14)	C13—C12—C17	118.0 (2)
O1—C1—C12	110.28 (17)	C13—C12—C1	119.0 (2)
O1—C1—C6	110.74 (17)	C17—C12—C1	122.9 (2)
C12—C1—C6	112.78 (18)	C14—C13—C12	120.9 (2)
O1—C1—C2	89.20 (14)	C14—C13—H13	119.6
C12—C1—C2	119.28 (18)	C12—C13—H13	119.6
C6—C1—C2	112.08 (17)	C15—C14—C13	120.1 (3)
C5—C2—C18	110.54 (19)	C15—C14—H14	119.9
C5—C2—C3	112.83 (19)	C13—C14—H14	119.9
C18—C2—C3	117.16 (19)	C14—C15—C16	119.9 (3)
C5—C2—C1	112.63 (18)	C14—C15—H15	120.1
C18—C2—C1	117.30 (18)	C16—C15—H15	120.1
C3—C2—C1	84.20 (15)	C15—C16—C17	120.3 (3)
N1—C3—O1	112.77 (18)	C15—C16—H16	119.8
N1—C3—C2	117.63 (19)	C17—C16—H16	119.8
O1—C3—C2	92.34 (15)	C16—C17—C12	120.7 (2)
N1—C3—H3	110.9	C16—C17—H17	119.6
O1—C3—H3	110.9	C12—C17—H17	119.6
C2—C3—H3	110.9	C2—C18—H18A	109.5
O2—C4—N1	122.7 (2)	C2—C18—H18B	109.5
O2—C4—N2	120.6 (3)	H18A—C18—H18B	109.5
N1—C4—N2	116.6 (2)	C2—C18—H18C	109.5
O3—C5—N2	120.4 (2)	H18A—C18—H18C	109.5
O3—C5—C2	121.7 (2)	H18B—C18—H18C	109.5
N2—C5—C2	117.8 (2)	N1—C19—H19A	109.5
C7—C6—C11	118.2 (2)	N1—C19—H19B	109.5
C7—C6—C1	120.6 (2)	H19A—C19—H19B	109.5
C11—C6—C1	121.07 (19)	N1—C19—H19C	109.5
C8—C7—C6	120.7 (2)	H19A—C19—H19C	109.5
C8—C7—H7	119.7	H19B—C19—H19C	109.5
C6—C7—H7	119.7	N2—C20—H20A	109.5
C9—C8—C7	120.7 (3)	N2—C20—H20B	109.5
C9—C8—H8	119.7	H20A—C20—H20B	109.5
C7—C8—H8	119.7	N2—C20—H20C	109.5
C8—C9—C10	119.4 (3)	H20A—C20—H20C	109.5
C8—C9—H9	120.3	H20B—C20—H20C	109.5
C10—C9—H9	120.3
C3—O1—C1—C12	−131.48 (18)	C20—N2—C5—C2	−170.0 (2)
C3—O1—C1—C6	102.98 (19)	C18—C2—C5—O3	37.6 (3)
C3—O1—C1—C2	−10.39 (16)	C3—C2—C5—O3	170.9 (2)
O1—C1—C2—C5	−102.41 (19)	C1—C2—C5—O3	−95.8 (3)
C12—C1—C2—C5	10.5 (3)	C18—C2—C5—N2	−144.8 (2)
C6—C1—C2—C5	145.47 (19)	C3—C2—C5—N2	−11.4 (3)
O1—C1—C2—C18	127.57 (19)	C1—C2—C5—N2	81.9 (2)
C12—C1—C2—C18	−119.5 (2)	O1—C1—C6—C7	−6.9 (3)
C6—C1—C2—C18	15.5 (3)	C12—C1—C6—C7	−131.1 (2)
O1—C1—C2—C3	9.93 (15)	C2—C1—C6—C7	91.0 (2)
C12—C1—C2—C3	122.9 (2)	O1—C1—C6—C11	177.12 (19)
C6—C1—C2—C3	−102.19 (18)	C12—C1—C6—C11	53.0 (3)
C4—N1—C3—O1	−72.4 (3)	C2—C1—C6—C11	−85.0 (2)
C19—N1—C3—O1	85.8 (3)	C11—C6—C7—C8	0.7 (4)
C4—N1—C3—C2	33.3 (3)	C1—C6—C7—C8	−175.3 (2)
C19—N1—C3—C2	−168.6 (2)	C6—C7—C8—C9	0.3 (4)
C1—O1—C3—N1	132.30 (19)	C7—C8—C9—C10	−1.1 (4)
C1—O1—C3—C2	10.93 (17)	C8—C9—C10—C11	0.7 (4)
C5—C2—C3—N1	−15.1 (3)	C9—C10—C11—C6	0.4 (4)
C18—C2—C3—N1	115.0 (2)	C7—C6—C11—C10	−1.1 (3)
C1—C2—C3—N1	−127.2 (2)	C1—C6—C11—C10	174.9 (2)
C5—C2—C3—O1	102.19 (19)	O1—C1—C12—C13	−27.7 (3)
C18—C2—C3—O1	−127.7 (2)	C6—C1—C12—C13	96.7 (2)
C1—C2—C3—O1	−9.95 (15)	C2—C1—C12—C13	−128.7 (2)
C3—N1—C4—O2	160.5 (2)	O1—C1—C12—C17	154.5 (2)
C19—N1—C4—O2	2.3 (4)	C6—C1—C12—C17	−81.1 (3)
C3—N1—C4—N2	−22.0 (3)	C2—C1—C12—C17	53.5 (3)
C19—N1—C4—N2	179.8 (2)	C17—C12—C13—C14	−0.8 (4)
C5—N2—C4—O2	169.6 (2)	C1—C12—C13—C14	−178.7 (2)
C20—N2—C4—O2	3.8 (3)	C12—C13—C14—C15	0.0 (4)
C5—N2—C4—N1	−7.9 (3)	C13—C14—C15—C16	0.5 (5)
C20—N2—C4—N1	−173.7 (2)	C14—C15—C16—C17	−0.1 (5)
C4—N2—C5—O3	−157.9 (2)	C15—C16—C17—C12	−0.7 (4)
C20—N2—C5—O3	7.7 (3)	C13—C12—C17—C16	1.2 (4)
C4—N2—C5—C2	24.4 (3)	C1—C12—C17—C16	179.0 (2)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···O2i	0.98	2.53	3.431 (3)	153
C7—H7···O1	0.93	2.37	2.745 (3)	104
C8—H8···O1ii	0.93	2.59	3.513 (3)	171
C13—H13···O1	0.93	2.41	2.752 (3)	101
C17—H17···O3	0.93	2.55	3.040 (3)	113
C20—H20B···O2	0.96	2.29	2.682 (4)	104

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3⋯O2i	0.98	2.53	3.431 (3)	153
C7—H7⋯O1	0.93	2.37	2.745 (3)	104
C8—H8⋯O1ii	0.93	2.59	3.513 (3)	171
C13—H13⋯O1	0.93	2.41	2.752 (3)	101
C17—H17⋯O3	0.93	2.55	3.040 (3)	113
C20—H20B⋯O2	0.96	2.29	2.682 (4)	104

Symmetry codes: (i) ; (ii) .