Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.chem.msu.ru/eng/misc/babaev/papers/088e.pdf Äàòà èçìåíåíèÿ: Thu Jan 20 21:59:28 2011 Äàòà èíäåêñèðîâàíèÿ: Sat Feb 12 03:10:56 2011 Êîäèðîâêà: ISO8859-5

organic papers
Acta Crystallographica Section E

Structure Reports Online
ISSN 1600-5368

3-Cyano-4,6-dimethyl-2-pyridone (Guareschi pyridone)

Victor B. Rybakov,* Alexander A. Bush, Eugene V. Babaev and Leonid A. Aslanov
Department of Chemistry, Moscow State University, 119992 Moscow, Russian Federation Correspondence e-mail: rybakov@biocryst.phys.msu.su

In the crystal structure of the title compound, C8H8N2O, the molecules form centrosymmetric dimers via N HÑÑÑO hydrogen bonds.

Received 1 December 2003 Accepted 18 December 2003 Online 10 January 2004

Comment
The `Guareschi pyridone' (3-cyano-4,6-dimethyl-2-pyridone), (3), has been known for more than a century (Guareschi, 1899). Surprisingly, an analysis of its crystal structure has never been performed. The title compound, (3), was prepared according to the classical scheme:

Key indicators Single-crystal X-ray study T = 293 K Ú Mean ' (CÁC) = 0.003 A R factor = 0.047 wR factor = 0.138 Data-to-parameter ratio = 13.0 For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

The six-membered heterocycle has a well de?ned diene-like structure; the bond distances C3 C4 and C5 C6 are shorter than the bonds C2 C3 and C4 C5 by more than 3 s.u. A search of the Cambridge Structural Database (CSD; Version of November 2002; Allen, 2002) gives very few hits for 4,6-disubstituted 3-cyano-2-pyridones. Among these are 3-cyano-6-phenyl-4-tri?uoromethyl-2-pyridone (Mishnev et al., 1986) and 3-cyano-6-methyl-2-pyridone (Munakata et al., 1996). The rigid cyano group has the standard linear structure, Ú the bond distance, C31 N31 of 1.130 (3) A, in compound (3) Ú being shorter by 0.01 A than the C N bond length in the two above-mentioned pyridones. The C C bonds of methyl Ú Ú groups C4 C41 [1.502 (3) A] and C6 C61 [1.504 (3) A] are almost equal in length. The latter is longer than the bond Ú distance C6 Ph (1.475 A) in 3-cyano-6-phenyl-4-tri?uoromethyl-2-pyridone (Mishnev et al., 1986); this can be explained by conjugation between the phenyl and pyridine rings. The N1 H1ÑÑÑO2 intermolecular hydrogen bond links the molecules in the crystal structure into centrosymmetric dimers (Fig. 2 and Table 2). The formation of such centrosymmetric dimers, through intermolecular hydrogen bonding, seems to be typical of 2-pyridones in the crystalline state (Cody, 1987; Dorigo et al., 1993; Mishnev et al., 1986; Munakata et al., 1996).

Experimental
Cyanoacetamide [NCCH2C(O)NH2] (33.98 g, 0.40 mol), (2), was dissolved in a solution of NaHCO3 (33.98 g, 0.40 mol) in 200 ml of H2O at 323 333 K. Acetylacetone [CH3C(O)CH2C(O)CH3] (40.45 g, 0.40 mol), (1), was added to this solution with vigorous stirring. The colour of the mixture turned yellow and then red, and 3 cyano 4,6 dimethyl 2 pyridone, (3), started to precipitate after 5 7 min. The mixture was allowed to stand overnight, the product ?ltered, washed
DOI: 10.1107/S1600536803029295 Acta Cryst. (2004). E60, o160 o161

# 2004 International Union of Crystallography Printed in Great Britain Á all rights reserved

o160

Victor B. Rybakov et al.



C8H8N2O


organic papers
Table 1
N1àC6 N1àC2 N1àH1 C2àO2 C2àC3 C3àC4

Ú Selected geometric parameters (A, ).
1.351 (2) 1.389 (2) 0.93 (2) 1.235 (2) 1.432 (3) 1.388 (3) 125.03 (16) 117.2 (13) 117.7 (13) 120.56 (17) 125.83 (18) 113.62 (15) 122.72 (17) 120.59 (16) 116.67 (16) C3àC31 C31àN31 C4àC5 C4àC41 C5àC6 C6àC61 N31àC31àC3 C3àC4àC5 C3àC4àC41 C5àC4àC41 C6àC5àC4 N1àC6àC5 N1àC6àC61 C5àC6àC61 1. 1. 1. 1. 1. 1. 445 130 411 502 358 504 (3) (3) (3) (3) (3) (3)

Figure 1

ORTEP 3 (Farrugia, 1997) plot of the molecule of the title compound. Displacement ellipsoids are drawn at the 50% probability level. H atoms are shown as spheres of arbitrary radii.

C6àN1àC2 C6àN1àH1 C2àN1àH1 O2àC2àN1 O2àC2àC3 N1àC2àC3 C4àC3àC2 C4àC3àC31 C2àC3àC31

178.69 118.54 121.13 120.33 119.63 120.46 115.58 123.96

(19) (17) (17) (17) (17) (18) (17) (18)

Table 2

Ú Hydrogen bonding geometry (A, ).
DàHÑÑÑA N1àH1ÑÑ ÑO2
i

DàH 0.93 (2)
xY 1 yY z.

HÑÑÑA 1.89 (2)

DÑÑ ÑA 2.810 (3)

DàHÑÑ ÑA 171 (2)

Symmetry code: (i) 1

Figure 2

PLUTON97 (Spek, 1997) diagram, showing the hydrogen bonds as dashed lines.

with cold water (3 Ò 150 ml), and dried (yield: 58.16 g, 97%). The product was recrystallized from C2H5OH; m.p. 563 565 K. Literature m.p. 563 K (Alberola et al., 1999). 1H NMR (CDCl3, 400 MHz, p.p.m.): 6.10 (s, 1H, 5H), 2.45 (3H, s, 4 CH3), 2.40 (3H, s, 6 CH3). The 1 H NMR spectrum of (3) was recorded on a Bruker AMX 400. Crystal data
C8H8N2O Mr = 148.16 Triclinic, P1 Ú a = 3.975 (4) A Ú b = 7.417 (4) A Ú c = 12.820 (8) A = 76.36 (4) = 88.54 (4) = 88.62 (4) Ú V = 367.1 (5) A3 Z=2 Dx = 1.340 Mg m 3 Cu K radiation Cell parameters from 25 re?ections = 22.5 27.0 " = 0.75 mm 1 T = 293 (2) K Cube, colourless 0.30 Ò 0.30 Ò 0.30 mm max = 69.9 h= 434 k= 839 l = 0 3 15 1 standard re?ection every 200 re?ections frequency: 60 min intensity decay: 1% w = 1/[' 2(Fo2) + (0.0689P)2 + 0.0196P] where P = (Fo2 + 2Fc2)/3 (Ñ/' )max < 0.001 Ú Ñ&max = 0.13 e A 3 Ú Ñ&min = 0.12 e A 3

The H atom bonded to N was re?ned isotropically. H atoms bonded to C atoms were included in calculated positions and re?ned Ú Ú as riding, with Csp2 H 0.93 A and Csp3 H 0.96 A. For methyl H atoms, Uiso values were set equal to 1.5Ueq of the carrier atom; for other H atoms, Uiso values were set equal to 1.2Ueq of the carrier atom. Data collection: CAD 4 EXPRESS (Enraf Nonius, 1994); cell re?nement: CAD 4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to re?ne structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP 3 for Windows (Farrugia, 1997) and PLUTON97 (Spek, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

The authors are indebted to the Russian Foundation for Basic Research for covering the licence fee for use of the Cambridge Structural Database (project No. 02-07-90322).

Data collection
Enraf Nonius CAD-4 diffractometer Non-pro?led 3 scans Absorption correction: none 1439 measured re?ections 1377 independent re?ections 924 re?ections with I > 2' (I) Rint = 0.047

References
Ò Alberola, A., Calvo, L. A., Ortega, A. G., Ru?, M. C. S., Yustos, P., Granda, S. Ò G. & Garc?a-Rodriguez, E. (1999). J. Org. Chem. 64, 9493 9498.. Allen, F. H. (2002). Acta Cryst. B58, 380 388. Cody, V. (1987). Acta Cryst. C43, 1325 1328. Dorigo, P., Gaion, R. M., Belluco, P., Fraccarollo, D., Maragno, I., Bombieri, G., Benetollo, F., Mosti, L. & Opini, F. (1993). J. Med. Chem. 36, 2475 2484. Enraf Nonius (1994). CAD-4 Software. Version 5.0. Enraf Nonius, Delft, The Netherlands. Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837 838. Guareschi, G. (1899). Chem. Zblt. 1, 289. Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany. Mishnev, A. F., Belyakov, S. V., Bleidelis, Ya. Ya., Apinitis, S. K., Gudrinietse, E. Yu. (1986). Kristallogra?ya (Crystallogr. Rep.), 31, 297 302. Munakata, M., Wu, L. P., Yamamoto, M., Kuroda-Sowa, T. & Maekawa, M. (1996). J. Am. Chem. Soc. 118, 3117 3124. Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Ø Gottingen, Germany. Spek, A. L. (1997). PLUTON97. University of Utrecht, The Netherlands.

Re?nement
Re?nement on F 2 R[F 2 > 2' (F 2)] = 0.047 wR(F 2) = 0.138 S = 1.08 1377 re?ections 106 parameters H atoms treated by a mixture of independent and constrained re?nement

Acta Cryst. (2004). E60, o160 o161

Victor B. Rybakov et al.



C8H8N2O

o161