The reactions of methyl esters of aroyl pyruvic acids (aroyl = benzoyl,p-chlorobenzoyl,p-bromobenzoyl andp-methylbenzoyl) with boric acid in acetic anhydride solution yield derivatives of the general formula (OAc)2B [OC(R)CHCOCOOMe] (R = C6H5,p-ClC6H4,p-BrC6H4 andp-CH3C6H4). The reactions of these derivatives with protic ligands such as glycols,o-aminophenol ando-aminothiophenol have also been carried out. These derivatives have been characterised by elemental analysis and molecular weight measurements. The tetra-coordination around central boron atom has been established byir,1Hnmr and 11 Bnmr spectral evidence.
