These common heterocyclic compound, 5932-27-4, name is Ethyl 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. Quality Control of Ethyl 1H-pyrazole-3-carboxylate
Methyl 1H-pyrazole-3-carboxylate (0.500 g, 3.96 mmol) was dissolved in dry MeCN (12 mL), then 2,2-dimethyloxirane (0.53 1 mL, 5.95 mmol) was added, followedby cesium carbonate (1.94 g, 5.95 mmol). The reaction mixture was stirred at 150 ¡ãC under microwave irradiation for 30 mm. The reaction mixture was cooled to rt, diluted with EtOAc (transesterification occurred upon EtOAc addition). The residue was purified by flash chromatography (solid loading on CELITE?, 20-100percent EtOAc/Hex) affording Intermediate 17A (0.305 g, 36percent yield) as a colorless syrup. MS(ESI) m/z: 213.0 (M+H)?H NMR: (400 MHz, DMSO-d6) oe ppm 7.50 (d, J=2.4 Hz, 1H), 6.83 (d, J2.4 Hz, 1H),4.40 (q, J=7.0 Hz, 2H), 4.17 (s, 2H), 2.77 (s, 1H), 1.39 (t, J=7.2 Hz, 3H), 1.20 (s, 6H).
The synthetic route of Ethyl 1H-pyrazole-3-carboxylate has been constantly updated, and we look forward to future research findings.
Reference:
Patent; BRISTOL-MYERS SQUIBB COMPANY; LADZIATA, Vladimir; GLUNZ, Peter W.; HU, Zilun; WANG, Yufeng; (0 pag.)WO2016/10950; (2016); A1;,
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