Novel buron heterocycles. I. 2,3-dihydro-1,3,2-benzodiazaborin-4(III)-ones and 1,2-dihydro- 1,3,2-benzodiazaborines

A series of 2,3-dihydro-1,3,2-benzodiazaborin-4(IH)-ones have been prepared and their ir spectra compared with those of their carbon isosteres. Solvolysis of these boron compounds in ethanol has been followed by uv and reveals a relationship between structure and rates of ethanol-ysis. Unexpectedly, these boron heterocycles, in contrast to their carbon isosteres, dissolve in aqueous alkali to form stable anions and the significance of this is discussed. The 1 :1 adducts of 1 and phosphorus oxychloride has been utilized to prepare two derivatives of the very stable 1,2-dihydro-2-phenyl-1,3,2-benzodiazaborin heterocycle.