A facile synthesis and characterization of Meulenhoff's free acid derived from 1,1 '-biphenyl-2,2 '-diol and its alkaloid complexes

A facile synthesis, separation and characterization of Meulenhoff's free ac id (HBB) derived from 1,1'-biphenyl-2,2'-diol were described. HBB, prepared by refluxing a mixture of 1,1'-biphenyl-2,2'-diol and boric acid in benzen e for 3 h, reacted with bulky alkaloids (quinine, quinidine, cinchonine, ci nchonidine, brucine and strychnine) in equimolar ratio in benzene or chloro form under reflux to give spiro[6,6]borate complexes in 72-99 % yields, The ir IR and H-1 NMR spectral characteristics are presented and discussed.