3994-50-1, name is 1-Methyl-4-nitro-1H-pyrazole, belongs to pyrazoles-derivatives compound, is considered to be a conventional heterocyclic compound, which is widely used in drug synthesis. The chemical synthesis route is as follows. COA of Formula: C4H5N3O2
The solution of compound 12 (11 g, 86.55mmol) and NCS(1.2 eq,13.87g, 103.85mmol) in dry THF (100 ml) was cooled to -78 C under N2. LiHMDS (1.5 eq, 26% in THF, 21.72g, 129.82mmol, 93.77mL) was added dropwise into the solution while the inner temperature was maintained at -78C. The reaction was stirred at same temperature for 2 h, and then warmed to room temperature and quenched with water (200 mL), extracted with EA, dried over anhydrous Na2SO4, filtered and evaporated. The residue was purified with column chromatography (PE:EA=20:1) to obtain the target compound 13 (7.0 g, 50 % yield).
The synthetic route of 3994-50-1 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Hangzhou Rex Pharmaceutical Co., Ltd; WANG, Yonghui; ZHOU, Juan; GAO, Yujun; WANG, Dong; HONG, Binbin; SHEN, Ximing; WU, Yaodong; LI, Chunqi; EP3476848; (2019); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics