title: Direct synthesis of pyrazoles from esters using tert-butoxide-assisted C-(C=O) coupling.
abstract: This paper describes the direct synthesis of pyrazoles from esters that comprises two sequential reactions: tert-butoxide-assisted C-C(=O) coupling reaction to yield β-ketonitrile or α,β-alkynone intermediates, and condensation by hydrazine addition. The method reported allows for easy control of the regioselectivity and structure of substituents at N-1, C-3, C-4 and/or C-5 positions.
authors.affiliation: Department of Chemistry & Research Institute of Natural Science, Gyeongsang National University, Jinju 660-701, Korea. yjyoon@gnu.ac.kr.
authors.forename: Bo Ram
authors.initials: BR
authors.lastname: Kim
authors.forename: Gi Hyeon
authors.initials: GH
authors.lastname: Sung
authors.forename: Ki Eun
authors.initials: KE
authors.lastname: Ryu
authors.forename: Sang-Gyeong
authors.initials: SG
authors.lastname: Lee
authors.forename: Hyo Jae
authors.initials: HJ
authors.lastname: Yoon
authors.forename: Dong-Soo
authors.initials: DS
authors.lastname: Shin
authors.forename: Yong-Jin
authors.initials: YJ
authors.lastname: Yoon
mesh_terms: D000440:Butanols / Q000737:chemistry; D003500:Cyclization; D004952:Esters; D006834:Hydrazines / Q000737:chemistry; D011720:Pyrazoles / Q000737:chemistry*
chemical_list: D000440:Butanols; D004952:Esters; D006834:Hydrazines; D011720:Pyrazoles; C029424:hydrazine; C077664:tert-butoxide, potassium