Synthesis of Bis-quinoxaline derivatives using tonsil clay as a catalyst

A convenient and efficient synthesis of new bis-quinoxaline is described, involving condensation of 1,2-diamines with 9-ethyl-3'6-di(1,2-dioxoethyl)carbazole in the presence of Tonsil clay, a readily available and inexpensive catalyst. The structures of all new products were identified by [sup.1]H-NMR, [sup.13]C-NMR and FT-IR spectral data and microanalysis. KEY WORDS: his-Quinoxalme, bis-Glyoxal, Green chemistry, 1,2-Diamine, Tonsil clay