88398-85-0Relevant academic research and scientific papers
Synthesis of Halosulfuron-methyl via Selective Chlorination at 3- and/or 5-Position of Pyrazole-4-carboxylates
Morimoto, Katsushi,Sato, Toshiaki,Yamamoto, Susumu,Takeuchi, Hiroshi
, p. 537 - 540 (2007/10/03)
Reactions of methyl pyrazole-4-carboxylates 4b-d with N-chlorosuccinimide under heating conditions without a solvent gave methyl 3,5-dichloro-1-methylpyrazole-4-carboxylate 4a in good yields. The reaction of 4a with sodium hydrosulfide led to a nucleophilic substitution on the 5-position regioselectively to afford methyl 3-chloro-1-methyl-5-mercaptopyrazole-4-carboxylate 6a, which was followed by oxidative chlorination and amination to obtain 3-chloro-1-methyl-5-sulfamoylpyrazole-4-carboxylate 2a. Finally, the reaction of 2a with phenyl 4,6-dimethoxypyrimidin-2-yl carbamate 7 provided methyl 3-chloro-5-(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-1-methylpyrazole-4- carboxylate (halosulfuron-methyl) 1a promising herbicide in corn.
Synthesis of 5-Chloropyrazoles by Chlorodiazoniation with Sulfur Dioxide
Yamamoto, Susumu,Morimoto, Katsushi,Sato, Toshiaki
, p. 1545 - 1547 (2007/10/02)
A facile synthesis of 5-chloropyrazoles 4a-e from 5-aminopyrazoles 2a-e via diazotization followed by chlorodediazoniation is described.A new application of sulfur dioxide as a catalyst was demonstrated to be the best for the chlorodediazoniation of diazonium chlorides 3a-e.
Herbicidal pyrazole sulfonyl Imino-2H-1,2,4-thiadiazolo[2,3-a9 pyrimidines
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, (2008/06/13)
Novel compounds of the formula: STR1 wherein R1 is a pyrazolyl group which may be substituted; R2 and R3 respectively are a lower alkyl group or a lower alkoxy group; and Z is CH or N, which are useful as herbicides.
