Regioselective Synthesis, NMR, and Crystallographic Analysis of N1-Substituted Pyrazoles

2017/07/18 by Adrian Huang, Kellie Wo, So Yeun Christine Lee +8 · 15 citations
Chemistry · Biochemistry, Genetics and Molecular Biology · #Synthesis and biological activity #Chemical Synthesis and Analysis #Click Chemistry and Applications

paper · doi:10.1021/acs.joc.7b01006

Abstract

A systematic study of the N-substitution reactions of 3-substituted pyrazoles under basic conditions has been undertaken. Regioselective N1-alkylation, -arylation, and -heteroarylation of 3-substituted pyrazoles have been achieved using K 2 CO 3 -DMSO. The regioselectivity is justified by the DFT calculations at the B3LYP/6-31G**(d) level. A consistent steric effect on chemical shift has been observed for N -alkyl pyrazole analogues. Twenty-five X-ray crystallographic structures have been obtained to confirm the regiochemistry of the major products.

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