Nitropyrazoles 17. Synthesis of 1-(3,5-dinitrophenyl)-4-methyl-3,5-dinitropyrazole and the study of its chemical transformations

• Published in: Russian chemical bulletin 2009-10, Vol.58 (10), p.2122-2128
• Main Authors: Zaitsev, A. A., Zaiko, D. V., Dalinger, I. L., Kachala, V. V., Shkineva, T. K., Shevelev, S. A.
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Full Articles; Inorganic Chemistry; Organic Chemistry
• ISSN: 1066-5285; 1573-9171
• DOI: 10.1007/s11172-009-0290-1

A new one-step method for the synthesis of 4-methyl-3(5)-nitropyrazole by nitration of 4-methylpyrazole is developed. Arylation of 4-methyl-3(5)-nitropyrazole with 1,3,5-trinitrobenzene gives 1-(3,5-dinitrophenyl)-4-methyl-3-nitropyrazole, nitration of which leads to 1-(3,5-dinitrophenyl)-4-methyl-3,5-dinitropyrazole. The action of 1 equiv. of an O- or S-nucleophile (phenolate, p -chlorobenzenethiolate and ethoxide ions; anions of glycolanilide and thioglycolanilide) on 1-(3,5-dinitrophenyl)-4-methyl-3,5-dinitropyrazole led to the substitution of the 5-NO 2 group of the pyrazole ring; under the action of one more equivalent of a nucleophile the NO 2 group of the benzene ring was substituted. The substitution product of the anion of thioglycolanilide for the 5-NO 2 group undergoes the intramolecular cyclization — oxidative nucleophilic hydrogen substitution in the benzene ring under the action of K 2 CO 3 .