Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 138786-86-4, name is Methyl 4-nitro-1H-pyrazole-3-carboxylate, A new synthetic method of this compound is introduced below., Recommanded Product: 138786-86-4
PART I: Synthesis Scheme I, shows that 4-nitro-1H-pyrazole-3-carboxylic acid (compound 12) was alkylated with methyl iodide in the presence of potassium carbonate in DMF. After flash chromatography on silica gel, two regioisomers, alkyl 1-alkyl-4-nitro-1H-pyrazole-3-carboxylate (compound 13a, 1,3-isomer) and alkyl 1-alkyl-4-nitro-1H-pyrazole-5-carboxylate (compound 13b, 1,5-isomer) were obtained in 26% and 74% yield, respectively. The structures of the isomers (compounds 13a, 13b) were determined by NOESY analysis: a NOESY correlation was observed between H-5 and alkyl protons in compound 13a.16 The nitro group of compounds 13a and 13b was reduced by hydrogenation in the presence of a catalytic amount of catalytic amount of 10% Pd/C to produce amines compounds 14a and 14b, respectively. Cyclization of compound 14b with urea afforded compound 15. Chlorination of compound 15 with POCl3 and DIPEA in toluene afforded compound 16 in 68% yield. Treatment with appropriate substituted anilines in isopropanol with 1 drop of conc. HCl with compound 16, provided the instant compounds 4-11 of this invention (65-78% yields).
The synthetic route of 138786-86-4 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Duquesne University of the Holy Spirit; Gangjee, Aleem; (26 pag.)US2019/276457; (2019); A1;,
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