Reaction of dehydro-d-erythorbic acid and its aryl analogs with ortho-diamines

Condensation of 3-(d-erythro -2,3,4-trihydroxy-l-oxobutyl)-2-quinoxalinone and its 6-chloro derivative (obtained by the reaction of d-erythro-2,3-hexodiulosono-1,4-lactone with ortho-diamines) with aryl- or aroyl-hydrazines gave 3-l-(phenylhydrazono)-d-erythro-2,3,4-trihydroxybutyl]-2-quinoxalinone (5) and relatives. Whereas boiling acetic anhydride causes the loss of two molecules of water per molecule of such hydrazones, affording, the 3-5-(acetoxymethyl)-l-arylpyrazol-3-yl]-2-quinoxalinones, identical with those obtained from the l-threo isomer, alkali causes the loss of only one molecule, affording, the corresponding flavazoles. Periodate oxidation of 5 gave 3-l-(phenylhydrazono)glyoxal-l-yl]-2-quinoxalinone, which afforded the corresponding mixed bis(hydrazones). A similar sequence of reactions was conducted with the aryl analogs, 4-phenyl-2,3-dioxobutano-1,4-lactone and its p-chlorophenyl derivative, whereby the 3-2-aryl-l-(arylhydrazono)-2-hydroxyethyl]2-quinoxalinones, were prepared; these were transformed into 3-(α-hydroxybenzyl)-flavazoles that gave monoacetyl derivatives.