Synthesis 2018; 50(18): 3686-3695
DOI: 10.1055/s-0037-1610191
paper
© Georg Thieme Verlag Stuttgart · New York

Synthetic Versatility of β-Alkoxyvinyl Trichloromethyl Ketones for Obtaining [1,2,4]Triazolo[1,5-a]pyrimidines

Laura A. Souza
a   Núcleo de Química de Heterociclos (NUQUIMHE), Universidade Federal de Santa Maria, Santa Maria, RS, 97105-900, Brazil   Email: nilo.zanatta@ufsm.br
,
Josiane M. Santos
a   Núcleo de Química de Heterociclos (NUQUIMHE), Universidade Federal de Santa Maria, Santa Maria, RS, 97105-900, Brazil   Email: nilo.zanatta@ufsm.br
,
a   Núcleo de Química de Heterociclos (NUQUIMHE), Universidade Federal de Santa Maria, Santa Maria, RS, 97105-900, Brazil   Email: nilo.zanatta@ufsm.br
,
Valquiria P. Andrade
a   Núcleo de Química de Heterociclos (NUQUIMHE), Universidade Federal de Santa Maria, Santa Maria, RS, 97105-900, Brazil   Email: nilo.zanatta@ufsm.br
,
a   Núcleo de Química de Heterociclos (NUQUIMHE), Universidade Federal de Santa Maria, Santa Maria, RS, 97105-900, Brazil   Email: nilo.zanatta@ufsm.br
,
Felipe B. Santos
a   Núcleo de Química de Heterociclos (NUQUIMHE), Universidade Federal de Santa Maria, Santa Maria, RS, 97105-900, Brazil   Email: nilo.zanatta@ufsm.br
,
Adailton J. Bortoluzzi
b   Departamento de Química, Universidade Federal de Santa Catarina, Florianópolis, SC, 88040-900, Brazil
,
Helio G. Bonacorso
a   Núcleo de Química de Heterociclos (NUQUIMHE), Universidade Federal de Santa Maria, Santa Maria, RS, 97105-900, Brazil   Email: nilo.zanatta@ufsm.br
,
Marcos A. P. Martins
a   Núcleo de Química de Heterociclos (NUQUIMHE), Universidade Federal de Santa Maria, Santa Maria, RS, 97105-900, Brazil   Email: nilo.zanatta@ufsm.br
,
a   Núcleo de Química de Heterociclos (NUQUIMHE), Universidade Federal de Santa Maria, Santa Maria, RS, 97105-900, Brazil   Email: nilo.zanatta@ufsm.br
› Author Affiliations
The authors are grateful for financial support from the Fundação de Amparo a Pesquisa do Estado do Rio Grande do Sul (FAPERGS/CNPq – PRONEX – Grant No. 16/2551-0000477-3), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq – Universal Grant No. 476341/2013-2) and for fellowships from CNPq (V.P.A.) and CAPES (L.A.S. and M.M.).
Further Information

Publication History

Received: 17 April 2018

Accepted after revision: 22 May 2018

Publication Date:
09 July 2018 (online)


Abstract

The synthetic versatility of 4-alkoxy-4-alkyl/aryl-1,1,1-trichloroalk-3-en-2-ones (enones) for the synthesis of [1,2,4]triazolo[1,5-a]pyrimidines, in which the trichloromethyl group is either maintained or eliminated from the product by simply controlling the reaction medium, is reported. These enones react with 3-amino-1H-1,2,4-triazoles under acidic conditions to furnish exclusively 7-(trichloromethyl)-[1,2,4]triazolo[1,5-a]pyrimidines, whereas under basic conditions [1,2,4]triazolo[1,5-a]pyrimidin-5/7(1H)-ones are obtained with elimination of the trichloromethyl group. The regioselectivity of the reactions performed under basic conditions is highly influenced by the substituents present in the starting enones. Twenty-one examples are synthesized using these two methodologies, with yields of up to 86%.

Supporting Information