69730-07-0Relevant articles and documents
Direct synthesis of pyrazoles from esters using tert-butoxide-assisted C-(C=O) coupling
Kim, Bo Ram,Sung, Gi Hyeon,Ryu, Ki Eun,Lee, Sang-Gyeong,Yoon, Hyo Jae,Shin, Dong-Soo,Yoon, Yong-Jin
, p. 9201 - 9204 (2015/06/08)
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.
VILSMEIER-HAACK REACTION OF 5-AMINO- AND 5-ACYLAMINO-PYRAZOLES
Simay, A.,Takacs, K.,Horvath, K.,Dvortsak, P.
, p. 127 - 140 (2007/10/02)
The Vilsmeier-Haack reaction of 5-aminopyrazole derivatives 1 was investigated in view of contradictory literature reports.Structure 2 of the products was proved both chemically and spectroscopically.The mechanism of the reaction was postulated on the basis of isolated intermediates 7 and 8. 5-Acylaminopyrazoles 9, 10 and 11 were found to give also 2 (and 7) under the Vilsmeier conditions by an acyl splitting reaction, proceeding probably via diacylamino derivatives 12.Compounds 2 provided a simple route to pyrazolopyrimidine derivatives 13 and 14 as well as to azomethine compounds 15-18.