Luo, Dingfeng published the artcileSynthesis of herbicide candidate through optimization of quinclorac with 3-methyl-1H-pyrazol-5-yl, Name: 1-(2-Chlorophenyl)-3-methyl-5-pyrazolone, the publication is Frontiers in Chemistry (Lausanne, Switzerland) (2021), 647472, database is CAplus and MEDLINE.
To enhance quinclorac potency, twenty-five derivatives I (R = Me, Et, Ph, PhCH2, etc.) containing 3-methyl-1H-pyrazol-5-yl moiety were synthesized by intermediate derivatization methods. The structure of the compound I (R = Me) was determined by X-ray diffraction. The activity of these compounds was affected by a substituent on the Ph group (for compounds with aryl-containing R substituent) in the following order: electron-withdrawing group > neutral group > electron-donating group. The herbicidal activity assays showed that compounds I (R = 2-FC6H4) (EC50 = 10.53 g/ha) and I (R = Me) (EC50 = 10.37 g/ha) have an excellent inhibition effect on barnyard grass in greenhouse experiment Greenhouse safety experiment on rice exhibited almost no difference in plant height and fresh weight treated with I (R = Me) at stage 1-2-leaf of rice after 14 days but I (R = 2-FC6H4) had a detrimental effect. Two season field assays showed I (R = Me) herbicidal activity on barnyard grass at 150 g/ha as equal as 300 g/ha quinclorac in fields in 2019 and 2020. The study demonstrated that I (R = Me) could be further researched as a potential herbicide to control barnyard grass in fields.
Frontiers in Chemistry (Lausanne, Switzerland) published new progress about 14580-22-4. 14580-22-4 belongs to pyrazoles-derivatives, auxiliary class Organic Pigment, name is 1-(2-Chlorophenyl)-3-methyl-5-pyrazolone, and the molecular formula is C10H9ClN2O, Name: 1-(2-Chlorophenyl)-3-methyl-5-pyrazolone.
Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics