Mild Nitration of Pyrazolin‐5‐ones by a Combination of Fe(NO3)3 and NaNO2: Discovery of a New Readily Available Class of Fungicides, 4‐Nitropyrazolin‐5‐ones

Mild Nitration of Pyrazolin‐5‐ones by a Combination of Fe(NO3)3 and NaNO2: Discovery of a New Readily Available Class of Fungicides, 4‐Nitropyrazolin‐5‐ones Full article

Journal

Chemistry: A European Journal
ISSN: 0947-6539 , E-ISSN: 1521-3765

Output data

Year: 2019, Volume: 25, Number: 23, Pages: 5922-5933 Pages count : 12 DOI: 10.1002/chem.201806172

Authors

Krylov Igor B. ^1,2 , Budnikov Alexander S. ^1,3,2 , Lopat'eva Elena R. ^3,1 , Nikishin Gennady I. ¹ , Terent'ev Alexander O. ^1,3,2

Affiliations

1	N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of, Sciences, 47 Leninsky prosp., Moscow, 119991 Russian Federation
2	All-Russian Research Institute for Phytopathology, B. Vyazyomy, Moscow Region, 143050 Russian Federation
3	Mendeleev University of Chemical Technology of Russia, 9 Miusskaya sq., Moscow, 125047 Russian Federation

4-Nitropyrazolin-5-ones have been synthesized by the nitration of pyrazolin-5-ones at room temperature by employing the Fe(NO3)3/NaNO2 system. The method demonstrated selectivity towards the 4-position of pyrazolin-5-ones even in the presence of NPh and allyl substituents, which are sensitive to nitration. It was shown that other systems containing FeIII and nitrites, namely Fe(NO3)3/tBuONO, Fe(ClO4)3/NaNO2, and Fe(ClO4)3/tBuONO, were also effective. Presumably, FeIII oxidizes the nitrite (NaNO2 or tBuONO) to form the NO2 free radical, which serves as the nitrating agent for pyrazolin-5-ones. The synthesized 4-nitropyrazolin-5-ones were discovered to be a new class of fungicides. Their in vitro activities against phytopathogenic fungi were found comparable or even superior to those of commercial fungicides (fluconazole, clotrimazole, triadimefon, and kresoxim-methyl). These results represent a promising starting point for the development of a new type of plant protection agents that can be easily synthesized from widely available reagents.

Krylov I.B. , Budnikov A.S. , Lopat'eva E.R. , Nikishin G.I. , Terent'ev A.O.
Mild Nitration of Pyrazolin‐5‐ones by a Combination of Fe(NO3)3 and NaNO2: Discovery of a New Readily Available Class of Fungicides, 4‐Nitropyrazolin‐5‐ones
Chemistry: A European Journal. 2019. V.25. N23. P.5922-5933. DOI: 10.1002/chem.201806172 WOS Scopus OpenAlex

Web of science:	WOS:000467184600014
Scopus:	2-s2.0-85063633018
OpenAlex:	W2918601905

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OpenAlex	19
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