Structure-property relationships in dicyanopyrazinoquinoxalines and their hydrogen-bonding-capable dihydropyrazinoquinoxalinedione derivatives.

Presented here is the design, synthesis, and study of a variety of novel hydrogen-bonding-capable π-conjugated -heteroacenes, 1,4-dihydropyrazino[2,3-]quinoxaline-2,3-diones (DPQDs). The DPQDs were accessed from the corresponding weakly hydrogen-bonding dicyanopyrazinoquinoxaline (DCPQ) suspensions with excess potassium hydroxide, resulting in moderate to good yields. Both families of compounds were analyzed by UV-vis and NMR spectroscopy, where the consequences of hydrogen bonding capability could be assessed through the structure-property studies.

A base-mediated synthesis of -hydroxy- and -alkoxyindoles from 2-nitrostyrenes.

Sequential treatment of alkyl 2-(2-nitroaryl)-2-butenoates with potassium -butoxide and an electrophile, such as methyl iodide, benzyl bromide and allyl bromide, afforded -alkoxyindoles. In related reactions, using sodium -pentoxide as the base with or without addition of an electrophile afforded -alkoxy- and -hydroxyindoles, respectively. Electrophiles such as dimethylsulfate, -tosyl chloride, and acetic anhydride afforded moderate yields of the respective -methoxy-, -tosyloxy, and -acetoxyindoles, while methyl iodide, benzyl bromide, and 1-bromohexane failed to form alkylated products using sodium -pentoxide as the base.