Synthesis of pinacol esters of 1??alkyl??1H??pyrazol??5??yl??and 1??alkyl??1H??pyrazol??4??ylboronic acids

AV Ivachtchenko, DV Kravchenko…

Index: Ivachtchenko, Alexandre V.; Kravchenko, Dmitry V.; Zheludeva, Valentina I.; Pershin, Dmitry G. Journal of Heterocyclic Chemistry, 2004 , vol. 41, # 6 p. 931 - 939

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Citation Number: 25

Abstract

Abstract Starting from 1H-pyrazol, a wide number of 1-alkyl-1H-pyrazol-4-yl and 1-alkyl-1H- pyrazol-5-ylboronic acids and their pinacol esters were synthesized and characterized. The key step in the described methodology is the regioselective lithiation of the pyrazole ring. The synthesized pinacolates are stable under prolonged storage and can be used as convenient reagents in organic synthesis.