Synthesis of trifluoromethyl-promoted functional pyrazolo [1,5-a]pyrimidine and pyrazolo [5,1-d] [1,2,3,5]tetrazine-4(3H)-ones

作者：Wu, YC; Chen, YJ; Li, HJ; Zou, XM; Hu, FZ; Yang, HZ^*

来源：Journal of Fluorine Chemistry, 2006, 127(3): 409-416.

DOI：10.1016/j.jfluchem.2006.02.001

• fluorine
• pyrazole
• pyrazolo[1,5-a]pyrimidine
• pyrazolo[5,1-d][1,2,3,5]tetrazine-4(3H)-one
• inhibitor

Ethyl 5-amino-3-trifluoroinethyl-1H-pyrazole-4-carboxylate (1) was efficiently synthesized via the condensation of ethyl cyanoacetate and trifluoroacetic anhydride, followed by chloridization and the condensation with aqueous hydrazine. Its unique reactivity was exploited for the synthesis of trifluoromethylated pyrazolo[1,5-a]pyrimidine (5) and pyrazolo[5,1-d][1,2,3,5]tetrazine-4(3H)-ones (8a-j). Among them, 5 was firstly found to be a novel fluorescent molecule that might be exploited as an attractive fluorophore for possessing many binding sites, and its fluorescence intensity was obviously stronger than its methyl analogue. 8 were found to be a new chemical class of potential monocotyledonous Echinochloa crus-galli L. Beauv, inhibitors, and were more active than their methyl analogues.

• 单位
  南开大学; 中国科学院; 元素有机化学国家重点实验室