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. 5334-40-7, name is 4-Nitro-1H-pyrazole-3-carboxylic acid, A new synthetic method of this compound is introduced below., Formula: C4H3N3O4
Synthesis of 4-nitro-1H-pyrazole-3-carboxylic acid methyl ester A 20 L reaction vessel equipped with a digital thermometer and stirrer was charged with 4-nitro-1H-pyrazole-3-carboxylic acid (1.117 Kg, 7.11 mol, 1 wt) and methanol (8.950 L, 8 vol). The reaction mixture was stirred under nitrogen, cooled to 0 to 5 C., thionyl chloride (0.581 L, 8.0 mol, 0.52 vol) added over 180 minutes and the resultant mixture allowed to warm to and stir at 18 to 22 C. overnight after which time 1H NMR analysis (d6-DMSO) indicated reaction completion. The reaction mixture was concentrated under reduced pressure at 40 to 45 C., the residue treated with toluene and re-concentrated (3*2.250 L, 3*2 vol) under reduced pressure at 40 to 45 C. to give 4-nitro-1H-pyrazole-3-carboxylic acid methyl ester as an off-white solid (1.210 Kg, 99.5% th).
The synthetic route of 5334-40-7 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; ASTEX THERAPEUTICS LIMITED; US2010/55094; (2010); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics