So far, in addition to halogen atoms, other non-metallic atoms can become part of the aromatic heterocycle, and the target ring system is still aromatic.Ivachtchenko, Alexandre V.; Kravchenko, Dmitry V.; Zheludeva, Valentina I.; Pershin, Dmitry G. researched the compound: (1-Isobutyl-1H-pyrazol-5-yl)boronic acid( cas:847818-64-8 ).Computed Properties of C7H13BN2O2.They published the article 《Synthesis of pinacol esters of 1-alkyl-1H-pyrazol-5-yl- and 1-alkyl-1H-pyrazol-4-ylboronic acids》 about this compound( cas:847818-64-8 ) in Journal of Heterocyclic Chemistry. Keywords: boronic acid pyrazolyl preparation bromopyrazole pyrazole lithiation borylation; pinacol boronic ester pyrazolyl preparation pyrazole lithiation borylation. We’ll tell you more about this compound (cas:847818-64-8).
1-Substituted pyrazolylboronic acids and their pinacol esters were prepared by lithiation-borylation reaction sequence starting from bromopyrazoles. Alkylation of 4-bromo-1H-pyrazole gave 1-alkyl-4-bromo-1H-pyrazoles, which were lithiated at -80° and borylated with B(OMe)3 to give 1-R-1H-pyrazole-4-boronic acids [4a-g, R = Me, Et, Pr, (CH2)2CHMe2, (CH2)2OMe, (CH2)3NMe2, (CH2)2CH(OEt)2]. Lithiation of 4-bromo-1-(2-dimethylaminoethyl)-1H-pyrazole (2h) gave 5-lithio-derivative, which on borylation afforded 1-R1-4-Br-1H-pyrazole-5-boronic acid (8). Boronic acids 4a-g are unstable and were deborylated slowly due to hydrolysis by traces of water; the stability of boryl derivatives can be greatly enhanced by converting to corresponding pinacol boronates (10a-g). Direct lithiation of 1-R2-1H-pyrazoles by BuLi at -20° afforded 5-lithio-derivatives, which were converted to corresponding 1-R2-1H-pyrazole-5-boronic acids [17a-e; R2 = Me, iBu, Pr, (CH2)2CHMe2, (CH2)2CH(OEt)2] and their pinacol boronates (18a-e, same R2). The key step in the described methodol. 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.
As far as I know, this compound(847818-64-8)Computed Properties of C7H13BN2O2 can be applied in many ways, which is helpful for the development of experiments. Therefore many people are doing relevant researches.
Reference:
1,8-Naphthyridine – Wikipedia,
1,8-Naphthyridine | C8H6N2 – PubChem