Ried, Walter; Stahlhofen, Paul published the artcile< Heterocyclic seven-membered ring systems. VII. The course of the reaction between ο-phenylenediamine and alkylidenepyruvic acids>, Category: esters-buliding-blocks, the main research area is .
The product from the condensation of ο-C6H4(NH2)2 (I) and PhCH:CHCOCO2H (II) is 2-hydroxy-3-styrylquinoxaline (III) and not 7-phenyl-2,3-benzo-1,4-diazacyclohepta-2,7-dien-5-one (IV) which is excluded since III was also obtained from I and II Me ester when the presence of O was carefully avoided. IV was obtained from I and BzCH2CO2Et (V). Analogs of III were also prepared I (2.1 g.) in 20 cc. alc. treated at 40-50° with an equimolar amount of RCH:CHCOCO2H gave 3-alkylidenemethyl-2-hydroxyquinoxalines (R, % yield, m.p., and crystallization solvent given): Ph (III), 57, 256°, dioxane; p-MeOC6H4, 61, 257°, dioxane; 2-furyl, 76, 262°, xylene; 3,4-(CH2O2)C6H3, 59, 300°, dioxane. 2-Hydroxy-3-methylquinoxaline (3.2 g.), 75 cc. xylene, 2.1 g. BzH, and 5-10 drops piperidine refluxed 5 hrs., 30 cc. solvent distilled, and the residue let stand several days precipitated III. III (1 g.) in 800 cc. EtOAc hydrogenated over Raney Ni, filtered, the EtOAc distilled, the oil in HOAc treated dropwise with a saturated aqueous solution of 2 g. NaNO2, kept 2 hrs., and filtered gave 1,4-dinitroso-2-hydroxy-3-(β-phenylethyl)-1,2,3,4-tetrahydroquinoxaline, m. 131° (decomposition) (alc. H2O). V (12.8 g.) in 50 cc. xylene added dropwise during 0.5 hr. to a boiling solution of 7.2 g. I in 50 cc. xylene, 30 cc. solvent distilled during 0.5 hr., and the mixture cooled gave 11 g. IV, m. 206° (dioxane); picrate, m. 168° (alc.). IV (3.3 g.) in 300 cc. EtOAc hydrogenated over Raney Ni and the filtered solution concentrated to 20 cc. gave 7-phenyl-2,3-benzo-1,4-diazacyclohept-2-en-5-one (VI), m. 167° (EtOAc); 1-NO derivative, m. 181° (decomposition) (MeOH). Similarly prepared were the 7-(2-furyl) analog of IV, m. 250° (dioxane) [pic-rate, m. 195° (decomposition) (alc.)], and the 7-(2-furyl) analog of VI, m. 169° (C6H6).
Chemische Berichte published new progress about Heterocyclic compounds, oxygen. 112-63-0 belongs to class esters-buliding-blocks, and the molecular formula is C19H34O2, Category: esters-buliding-blocks.
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics