2-methyl-7-substituted pyrazolo[1,5-a]pyrimidines: highly regioselective synthesis and bromination

Journal of the Brazilian Chemical Society

Scapin, Elisandra¹  Rosa, Fernanda A.¹  Zanatta, Nilo¹  Bonacorso, Helio G.¹  Martins, Marcos A. P.¹  Universidade Federal do Tocantins, Palmas, Brazil¹  Frizzo, Clarissa P.¹  Universidade Federal de Santa Maria, Santa Maria, Brazil¹ 

关键词: pyrimidines;    pyrazoles;    pyrazolo[1;    5-a]pyrimidines;    enones;    bromination;   

DOI  :  10.1590/S0103-50532009000200003

学科分类：化学（综合）

来源: SciELO

【 摘 要 】

The reaction of 3-amino-5-methyl-1H-pyrazole with 1,1,1-trichloro-4-alkoxy-3-alken-2-ones [CCl3C(O)CH=C(R1)OR, where R1/R = H/Me, Me/Et, Et/Me, Pr/Et, Bu/Me, iso-Bu/Me] or β-dimethylaminovinyl ketones [R2C(O)CH=CHNMe2, where R2 = Ph, Ph-4-Me, Ph-4-F, Ph-4-Cl, Ph-4-Br, Ph-4-NO2, fur-2-yl, thien-2-yl, pyrrol-2-yl, pyrid-2-yl], in acetic acid under reflux for 16 hours, furnished highly regioselective the halomethylated pyrazolo[1,5-a]pyrimidines and aryl[heteroaryl]pyrazolo[1,5-a]pyrimidines, respectively. A protocol for the bromination reaction at the 3-position pyrazolo[1,5-a]pyrimidines also was investigated.

【 授权许可】

Unknown