title: Mode of formation of quinoxaline versus 2[1H]-quinoxalinone rings from dehydro-D-erythorbic acid.
abstract: The mode of formation of the quinoxaline versus 2[1H]-quinoxalinone rings by the reaction of o-diamines with dehydro-D-erythorbic acid has been investigated. The study was carried out by using one and two molar equivalents of 1,2-diamino-4,5-dimethylbenzene (3b) to give 6,7-dimethyl-3-(1-oxo-D-erythro-2,3,4-trihydroxybutyl)-2[1H]-quino xalinone (4b) and 2-(2-amino-4,5-dimethylphenylcarbamoyl)-3-(D-erythro-glycerol-1-yl )- 6,7-dimethylquinoxaline (6), respectively. The former product exists predominantly as the two furanosyl anomers. Sequential reaction of 4a with 3b has been studied, and the location of each diamine in the product was deduced by using 1H-n.m.r. spectroscopy. A mechanism for the reaction is proposed. Acetate and acetal derivatives of the compound are prepared.
authors.affiliation: Chemistry Department, Faculty of Science, Alexandria University, Egypt.
authors.forename: A
authors.initials: A
authors.lastname: Mousaad
authors.forename: N
authors.initials: N
authors.lastname: Rashed
authors.forename: H A
authors.initials: HA
authors.lastname: Hamid
authors.forename: Y
authors.initials: Y
authors.lastname: el Kilany
authors.forename: E S
authors.initials: ES
authors.lastname: el Ashry
mesh_terms: D003683:Dehydroascorbic Acid / Q000737:chemistry*; D011810:Quinoxalines / Q000138:chemical synthesis*
chemical_list: D011810:Quinoxalines; C048679:dehydroerythorbic acid; D003683:Dehydroascorbic Acid