A Convenient Synthesis and Herbicidal Activity of N-phosphonoalkylpyrazolo[4,3-e][1,2,4]-triazolo[1,5-d]pyrimidines

Authors: Xiao, Lin-Xia; Li, Ke; Shi, De-Qing

Source: Phosphorus, Sulfur, and Silicon and the Related Elements, Volume 183, Number 12, December 2008 , pp. 3156-3165(10)

Publisher: Taylor and Francis Ltd

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Abstract:

An important building block, diethyl [(5-amino-4-cyano-3-methylsulfanyl-pyrazol-1-yl)-(4-fluorophenyl)methyl] phosphonate (3) was efficiently synthesized via the condensation of 1-hydrazino-1-(4-fluorophenyl)methyl phosphonate (1) with 2-[bis(methylthio)methylene]malononitrile (2).3 reacted with triethyl orthoformate to afford diethyl [(4-cyano-5-ethoxymethyleneamino-3-methylsulfanyl-pyrazol-1-yl)-(4-fluorophenyl)methyl] phosphonate (4), which reacted with various acyl hydrazines in refluxing 2-methoxyethanol to provide the target compounds (5) in good yields directly. The results of preliminary bioassay indicated that compounds 5 possess potent herbicidal activity against the roots of monocotyledonous (barnyard grass) and dicotyledonous (oil rape) plants, and could be further developed as potential herbicides.

Keywords: 1-Aminoalkyl phosphonate analog; herbicidal activity; pyrazolo[4,3-e][1,2,4]triazolo[1,5-d]pyrimidine; synthesis

Document Type: Research article

DOI: http://dx.doi.org/10.1080/10426500802070270

Affiliations: 1: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei, P. R. China

Publication date: 2008-12-01