Selective Herbicidal Activities of Ethyl 5-(4, 6-Dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-1-methylpyrazole-4-carboxylate and Its Related Compounds

Abstract

Twenty-six derivatives of pyrazole-5-sulfonylurea.s were synthesized and investigated for their herbicidal activities.The title compound, pyrazosulfuron-ethyl (5, code No. NC-311), was found the best compound that was highly effective in controlling paddy weeds, especially annual and perennial broad-leaf weeds and sedges. In the paddy-field trial, 5 effectively controlled weeds at the rate of 20-30 g a.i. /ha without phytotoxicity to transplanted rice. This herbicide is proposed as a potent novel herbicide to protect paddy rice.

Chemistry of Pyrazole-3(5)-Diazonium Salts (Review)*

“…The interaction of diazonium salts 1 (R = 3-Py, R 1 = H, NO 2 ) with ammonia solution led to formation of the starting aminopyrazole and evolution of nitrogen [52]. Sandmeyer and Balz-Schiemann reactions were used to convert compounds 1 into a series of functionalized 3(5)-derivatives of pyrazole: fluorides 12 [53][54][55], chlorides 13 and bromides 14 [44,52,53,[56][57][58][59][60][61], iodides 15 [22,44,51,52], nitropyrazoles 16 [56,[62][63][64], azides 17 [57,61,[64][65][66], methyl sulfides 18 [44], and sulfonyl chlorides 19 [67][68][69].…”

Weed Control, 2. Individual Herbicides

“…Halosulfuron-methyl is produced by reaction of N-1-methyl-3-chloro-4-carboxymethyl-5-sulfonylisocyanate pyrazole with 2-amino-4,6-dimethoxypyrimidine [59].…”