A triphenylboroxin derivative possessing two intramolecular chelates

Condensation of 2-formylbenzeneboronic acid and 1,1-dimethylhydrazine afforded the title compound, bis(8-B-4)-1,3,5-tris[2-[(N,N-dimethylhydrazono)methyl]-phenyl)]b oroxin, C27H33B3N6O3, a tridehydro cyclic trimer of the expected simple benzaldehyde hydrazone and the first triphenylboroxin derivative found to possess two B chelating interactions. The double chelation induces molecular asymmetry but effects only a slight puckering in the central boroxin ring.