Reference of 378203-86-2, These common heterocyclic compound, 378203-86-2, name is Ethyl 1-methyl-4-nitro-1H-pyrazole-3-carboxylate, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
INTERMEDIATE 13 Ethyl 4-amino-i -methylpyrazole-3 -carboxylateTin(II) chloride dihydrate (7.42 g, 32.9 mmol) was added to a solution ofIntermediate 12 (i.3i g, 6.58 mmol) in EtOH (50 mL). The reaction was heated at 50Cwith stirring for 3.5 h, then cooled to room temperature and concentrated in vacuo. The residue was diluted with DCM and treated with 2M aqueous NaOH solution. A viscous thick precipitate formed. The mixture was filtered through celite, and the two layers were separated. The aqueous layer was extracted with DCM (twice). The combined organiclayers were passed through a phase separator cartridge, then evaporated. The resulting crude material was purified by silica gel chromatography (gradient 25-75% EtOAc in isohexane). The title compound (0.32 g, 29%) was isolated as a dark blue/black oil. oH (400 MHz, DMSO-d6) 7.i2 (s, iH), 4.66 (s, 2H), 4.23 (q, 2H,J7.i Hz), 3.76 (s, 3H), i.27 (t, 3H,J7.i Hz).
Statistics shows that Ethyl 1-methyl-4-nitro-1H-pyrazole-3-carboxylate is playing an increasingly important role. we look forward to future research findings about 378203-86-2.
Reference:
Patent; FORD Daniel James; HUANG Qiuya; NEUSS Judi Charlotte; REUBERSON James Thomas; VANDERHOYDONCK Bart; WO2015/193168; (2015); A1;,
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