Dihydrobis borate, reaction

Pyrazaboles substituted on either the ring or the boron may be obtained by reaction between the appropriately substituted pyrazole and the appropriately substituted borane.11 For example the 2,6-dibromo-4,4,8,8-tetraethylpyrazabole can be made by the reaction between 4-bromopyrazole and pyrophoric triethylborane in xylene at reflux temperature. Another route to such compounds involves the dihydrobis(l-pyrazolyl)borate... 

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