R e p le 1 1 juillet 1983 MICHEL BARON, SYLVIANE GIORGI-RENAULT, JEAN RENAULT, PATRICK MAILLIET, DANIEL CARRE et JEAN ETIENNE. Can. J. Chem. 62, 526 (1984).La butanedione rCagit i chaud avec la diamino-1,2 anthraquinone pour donner, non pas la dimCthy1-2,3 naphto[2,3$]quinoxalinedione-7,12 3 attendue, mais l'(hydroxy-2 mCthyl-2 0x0-3 butyl)-2 mCthyl-3 naphto[2,3$]quinoxalinedion_e-7,12 4n dont la structure est Ctablie par diffraction de rayons-X. Elle cristal!ise dans le groupe d'espace triclinique P 1 avec les dimensions de maille n = 9,091 (l), b = 16,966 (4), c = 12,375 (3) A, a = 100,75 (2), P = 101,83 (2), y = 100,29 (2) 526 (1984).Butanedione reacts on heating with 1,2-diaminoanthraquinone to give, not the expected 2,3-dimethylnaphtho[2,3-flquinoxaline-7,12-dione 3, but 2-(2-hydroxy-2-methyI-3-oxobutyl)-3-methylnaphtho[2,3$]quinoxaline-7,12-dione 4n whose structure was established by X-ray diffraction. This compound crystallizes in the triclinic P 1 space group with unit cell dimensions of n = 9.091 ( l ) , b = 16.966 (4), c = 12.375 (3) A; a = 100.75 (2), P = 101.83 (2), y = 100.29 (2)", V = 1789 A', Z = 4. The structure was resolved by the direct method and refined to R = 0.039 for 3027 independent reflections. The overall conformation of the molecule is essentially planar. The principal characteristic is the presence of two cyclic arrangements caused by intramolecular hydrogen bonding. 2,3-Dimethylnaphtho[2,3-j]quinoxaline-7,12-dione is the intermediate in this reaction.[Journal translation]
