3-(Ethoxy­carbonyl­di­hydroxy­methyl)-2-oxo-1,2-di­hydro­quinox­aline

The crystal structure of the title compound, ethyl 2,2-di­­hy­droxy-2-(3-oxo-3,4-di­hydro­quinoxalin-2-yl)­acetate, C₁₂H₁₂N₂O₅, indicates a short intramolecular contact between the N1 atom and a hydroxyl group [2.772 (4) Å]. Two intermolecular hydrogen bonds participate in the molecular packing.

S1. Comment

Interest in quinoxaline derivatives has increased greatly during recent years due to their different applications in various areas. Some derivatives are used as colorimetric agents (Campaigne & McLaughlin, 1983), antibacterial agents (Boutti & Lecolier, 1976) and colouring matter. Other derivatives possess various biological activities (Dalgaard et al., 1994; De Clercq, 1998; Habib & El Hawash, 1997; Johnson et al., 1968; Li et al., 1997). In a previous paper (Benchimdi et al., 1993), we reported the reaction of 3-ethoxycarbonylmethyl-2-oxo-1,2-dihydroquinoxaline, (I), with bromide which allowed 3-ethoxycarbonylbromomethyl-2-oxo-1,2-dihydroquinoxaline, (II), to be obtained. The latter proved to be a useful key intermediate, leading to novel quinoxalines functionalized on a carbon of the ester group. Further reaction of (II) in dimethylformamide with sodium azidure in water at low temperature provided 3-ethoxycarbonylazidomethyl-2-oxo-1,2-dihydroquinoxaline, (III), and as a result of the substitution of bromide, an unexpected 3-(ethoxycarbonyldihydroxymethyl)-2-oxo-1,2-dihydroquinoxaline, (IV), the structure of wich has been determined by X-ray diffraction. The quinoxaline bicycle N1/C2/C3/N4/C5/C6/C7/C8/C9/C10 is planar (r.m.s. deviation 0.006 Å). The O5 and C11 atoms are located in this plane [at −0.0168 (4) and −0.0962 (5) Å, respectively] which is at an angle of 75.8 (4)° to the ethoxycarbonyl group (plane O4/C11/O3/C12/C13: r.m.s. deviation 0.014 Å). In the crystal structure, the molecules are linked by two intermolecular hydrogen bonds between N1 and O5, and between O21 and N4. Atom N4ⁱⁱ is only 2.772 (4) Å from O22 but an intramolecular hydrogen bond does not seem possible, the N···H22—O22 angle being 101.52 (6)° and the N4···H22 distance of 2.505 (6) Å is too large [symmetry code: (ii) 2 − x, 1/2 + y, 1/2 − z].

S2. Experimental

To a solution (0.003 mol) of sodium nitrite in dimethylformamide (15 ml) and water (15 ml) at 273 K, a solution (0.003 mol) of (II) in dimethylformamide (15 ml) was added dropwise under vigorous stirring. The mixture was stirred for 12 h, then the solvent was removed under vacuum and the resulting material was chromatographed on a silica-gel column using a 10:90 mixture of ethyl acetate and hexane, to give compounds (III) and (IV).

Computing details

Data collection: KappaCCD Software (Nonius, 1998); data reduction: DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: maXus (Mackay et al., 1999); software used to prepare material for publication: maXus.

(IV)

Crystal data

C12H12N2O5	F(000) = 552
Mr = 264.24	Dx = 1.44 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.6475 (4) Å	Cell parameters from 2522 reflections
b = 9.2255 (3) Å	θ = 1–25.6°
c = 17.521 (5) Å	µ = 0.11 mm^−1
β = 99.122 (2)°	T = 298 K
V = 1220.5 (4) Å^3	Prism, yellow-red
Z = 4	0.25 × 0.20 × 0.15 mm

Data collection

KappaCCD diffractometer	Rint = 0.035
Radiation source: fine-focus sealed tube	θmax = 25.6°
ϕ scans	h = 0→9
2363 measured reflections	k = 0→10
2363 independent reflections	l = −21→21
1919 reflections with I > 3.00 σ(I)

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: geom, diff
R[F^2 > 2σ(F^2)] = 0.049	H-atom parameters not refined
wR(F^2) = 0.054	Weighting scheme based on measured s.u.'s w = 1/[σ^2(Fo^2) + 0.03Fo^2]
S = 1.48	(Δ/σ)max = 0.048
1919 reflections	Δρmax = 0.31 e Å^−3
175 parameters	Δρmin = −0.25 e Å^−3
Primary atom site location: structure-invariant direct methods

Special details

Refinement. Refinement on F²

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

	x	y	z	Uiso*/Ueq
C2	1.00453 (6)	0.35888 (5)	0.08713 (3)	0.0300 (3)
C3	1.01578 (6)	0.24799 (5)	0.14764 (3)	0.0237 (2)
C5	0.85783 (6)	0.08368 (5)	0.06382 (2)	0.0251 (2)
C6	0.78198 (7)	−0.05384 (5)	0.05070 (3)	0.0338 (3)
C7	0.69420 (7)	−0.08958 (6)	−0.02114 (3)	0.0387 (3)
C8	0.67994 (7)	0.00951 (6)	−0.08142 (3)	0.0393 (3)
C9	0.75245 (7)	0.14533 (6)	−0.07055 (3)	0.0368 (3)
C10	0.84153 (6)	0.18236 (5)	0.00291 (3)	0.0272 (2)
C11	1.10392 (6)	0.29580 (5)	0.22763 (3)	0.0277 (2)
C12	1.27957 (7)	0.37484 (6)	0.22710 (3)	0.0343 (3)
C13	1.55367 (8)	0.36486 (9)	0.18018 (4)	0.0714 (4)
C14	1.54884 (10)	0.46488 (10)	0.11562 (5)	0.0931 (6)
N1	0.91836 (5)	0.31718 (4)	0.01716 (2)	0.0324 (2)
N4	0.94871 (5)	0.12005 (4)	0.13666 (2)	0.02470 (19)
O3	1.37893 (5)	0.30490 (4)	0.18381 (2)	0.0483 (2)
O4	1.32116 (5)	0.48118 (4)	0.26495 (2)	0.0549 (2)
O5	1.07103 (5)	0.48073 (4)	0.09925 (19)	0.0447 (2)
O21	0.98053 (4)	0.38644 (4)	0.25411 (19)	0.03907 (19)
O22	1.15233 (5)	0.18049 (4)	0.27846 (2)	0.0465 (2)
H1	0.91107	0.3867	−0.0192	0.0421*
H6	0.7915	−0.1227	0.0922	0.0439*
H7	0.6426	−0.1842	−0.0297	0.0503*
H8	0.6174	−0.0160	−0.1315	0.0511*
H9	0.7436	0.2123	−0.1129	0.0478*
H13A	1.5980	0.4127	0.2280	0.0928*
H13B	1.6328	0.2880	0.1716	0.0928*
H14A	1.6640	0.5042	0.1131	0.1210*
H14B	1.4697	0.5418	0.1243	0.1210*
H14C	1.5045	0.4171	0.0678	0.1210*
H21	1.0424	0.4515	0.2914	0.0508*
H22	1.0720	0.1271	0.2779	0.0604*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C2	0.0382 (3)	0.0262 (3)	0.0237 (3)	−0.0002 (2)	−0.0021 (2)	0.0012 (2)
C3	0.0241 (3)	0.0244 (3)	0.0218 (2)	0.0008 (2)	0.00173 (19)	−0.00107 (19)
C5	0.0247 (3)	0.0276 (3)	0.0222 (2)	0.0005 (2)	0.0032 (2)	−0.0037 (2)
C6	0.0392 (3)	0.0296 (3)	0.0315 (3)	−0.0068 (2)	0.0044 (2)	−0.0031 (2)
C7	0.0407 (3)	0.0341 (3)	0.0395 (3)	−0.0093 (2)	0.0022 (3)	−0.0105 (2)
C8	0.0372 (3)	0.0464 (4)	0.0314 (3)	−0.0004 (3)	−0.0061 (2)	−0.0127 (3)
C9	0.0439 (3)	0.0400 (3)	0.0241 (3)	0.0022 (3)	−0.0041 (2)	−0.0014 (2)
C10	0.0295 (3)	0.0266 (3)	0.0243 (2)	0.0005 (2)	0.0006 (2)	−0.0031 (2)
C11	0.0324 (3)	0.0267 (3)	0.0225 (2)	−0.0003 (2)	−0.0008 (2)	0.0005 (2)
C12	0.0346 (3)	0.0394 (3)	0.0271 (3)	−0.0026 (2)	−0.0013 (2)	−0.0040 (2)
C13	0.0293 (3)	0.1091 (6)	0.0755 (5)	−0.0100 (4)	0.0149 (3)	−0.0256 (4)
C14	0.0672 (5)	0.1170 (7)	0.0950 (6)	−0.0453 (5)	0.0250 (4)	−0.0216 (5)
N1	0.0457 (3)	0.0259 (2)	0.0231 (2)	−0.0037 (2)	−0.00479 (18)	0.00395 (17)
N4	0.0278 (2)	0.0247 (2)	0.0208 (2)	−0.00033 (18)	0.00293 (16)	−0.00069 (16)
O3	0.0311 (2)	0.0609 (3)	0.0522 (2)	−0.00206 (19)	0.00840 (18)	−0.0180 (2)
O4	0.0528 (3)	0.0594 (3)	0.0515 (2)	−0.0235 (2)	0.01059 (19)	−0.0269 (2)
O5	0.0686 (3)	0.0274 (2)	0.0337 (2)	−0.01520 (19)	−0.01124 (18)	0.00527 (16)
O21	0.0370 (2)	0.0440 (2)	0.03522 (19)	−0.00191 (17)	0.00545 (16)	−0.01747 (17)
O22	0.0644 (3)	0.0373 (3)	0.0332 (2)	−0.00895 (19)	−0.0126 (2)	0.01006 (18)

Geometric parameters (Å, º)

O3—C12	1.3236 (6)	C13—C14	1.4557 (10)
C3—C11	1.5211 (6)	N1—C10	1.3814 (6)
C3—C2	1.4660 (6)	N1—C2	1.3524 (6)
C6—C5	1.3988 (6)	N4—C3	1.2892 (5)
C6—C7	1.3696 (7)	N4—C5	1.3940 (5)
C7—C8	1.3880 (7)	O3—C13	1.4570 (7)
C9—C10	1.3998 (6)	O4—C12	1.1986 (6)
C9—C8	1.3713 (7)	O5—C2	1.2383 (5)
C10—C5	1.3933 (6)	O21—C11	1.3943 (5)
C12—C11	1.5299 (7)	O22—C11	1.3991 (6)
C2—C3—C11	115.51 (4)	N4—C3—C2	123.69 (4)
C3—N4—C5	119.07 (4)	N4—C5—C10	121.00 (4)
C6—C7—C8	120.57 (5)	N4—C5—C6	120.16 (4)
C7—C6—C5	119.96 (5)	O3—C12—C11	110.83 (4)
C9—C10—C5	121.08 (4)	O3—C12—O4	126.16 (5)
C9—C8—C7	120.99 (4)	O3—C13—C14	111.36 (5)
C10—C5—C6	118.84 (4)	O4—C12—C11	122.89 (5)
C10—C9—C8	118.55 (5)	O5—C2—C3	122.28 (4)
C10—N1—C2	123.52 (4)	O5—C2—N1	122.79 (4)
C12—C11—C3	113.20 (4)	O21—C11—C12	110.94 (4)
C12—O3—C13	116.99 (4)	O21—C11—C3	104.83 (3)
N1—C10—C5	117.78 (4)	O21—C11—O22	111.65 (4)
N1—C10—C9	121.13 (4)	O22—C11—C12	102.85 (4)
N1—C2—C3	114.92 (4)	O22—C11—C3	113.57 (4)
N4—C3—C11	120.71 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O5^i	0.90	1.88	2.7741 (5)	171
O21—H21···N4^ii	0.96	1.99	2.8762 (5)	152

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