condensation of glyoxal, formaldehyde and anilines lead to the formation of 2,4,6,8- tetraphenyl and substituted phenyl 2,4,6,8-tetraazabicyclo [3.3.0] octanes. the reactions are sensitive to ph and temperature. ortho derivatives of anilines do not participate in this condensation. x-ray structural determination reveals a cis-dienvelope geometery about the two fused rings.
