Synthesis and herbicidal activity of novel 6-arylthio-3-methylthio-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-ones

Design, synthesis, and herbicidal activity of novel 2-(arylamino)-5-methyl-4-methylene-7-(methylthio)-4H-pyrido[4,3-d][1,3]oxazine-8-carbonitrile derivatives

“…The target compounds 4a-4k were screened for herbicidal activities against radish (Raphanus sativus), grain sorghum (Sorghum bicolor), cucumber (Cucumis sativus), purple medic (Medicago sativa), rape (Brassica napus), and barnyard grass (Echinochloa crusgalli) at concentrations of 100 mg L −1 and 10 mg L −1 using a Petri dish method. 22 As shown in Table S2 (in Supporting Information), compound 4i shows a >90% inhibition rate to the stalk and root of barnyard grass at 100 mg L −1 . Compound 4g displays 100% inhibition rate to the stalk and root of grain sorghum at 100 mg L −1 .…”

“…19,20 Some N-containing compounds, which are not easily prepared by other methods, have been synthesized via the tandem aza-Wittig reactions of functionalized iminophosphoranes under mild conditions. 21 The tandem aza-Wittig reactions of functionalized iminophosphoranes were also applied in the synthesis of many fused N-heterocycles such as pyrazolopyrimidine, 22 triazolopyrimidine, 23 thienopyrimidine, 24 pyridopyrimidine, 25 imidazolopyrimidine, 26 and furopyrimidine derivatives. 27 Recently, we have become interested in the synthesis of new bioactive fused heterocycles, such as pyrido [4,3-d][1,3]oxazines from iminophosphoranes, with the aim of evaluating their herbicidal activities.…”

aza-Wittig Reaction with Nitriles: How Carbonyl Function Switches from Reacting to Activating

“…The aza -Wittig reaction, a well-known rapid access to CN bond construction, provides numerous opportunities for the synthesis of N -containing organic molecules. In this context, the use of the aza -Wittig reaction for the synthesis of N -heterocycles is of primary concern, owing to a broad abundance of such structures in both natural and synthetic bioactive compounds. Moreover, among U.S. FDA-approved unique small-molecule pharmaceuticals, 59% of drugs contain an N -heterocycle …”