Reference of 14531-55-6,Some common heterocyclic compound, 14531-55-6, name is 3,5-Dimethyl-4-nitro-1H-pyrazole, molecular formula is C5H7N3O2, 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.
To a solution of 3 5-dimethyl-4-nitropyrazole (Fluorochem, Derbyshire, UK1 989 mg, 7 01 mmol) in DMF (40 ml) was added in two portions 55% NaH in oil (420 mg, 9 63 mmol) The reaction mixture was stirred for 30 mm at rt then 2-bromoethyl methyl ether (Aldrich, Buchs, Switzerland, 1 17 g, 8 42 mmol) was added and the reaction mixture stirred for 2 h at rt The reaction mixture was quenched wtth water and extracted with EtOAc The organic layer was washed with water (2x) and brine (2x), d?ed over Na2SO4, filtered and evaporated The crude product was purified by Prep HPLC (H2O (0 1% TFA)/CH3CN 95 5 to 50 50 ?verse phase silica gel) The fractions containing product were collected together, basified with NaHCO3 and concentrated before being extracted with EtOAc (3x) The combined organic layers were washed with brine, dried over Na2SO4, filtered and evaporated to give the title compound as a white solid (HPLC tR 2 57 mm (Method A), M+H = 200 MS-ES).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 3,5-Dimethyl-4-nitro-1H-pyrazole, its application will become more common.
Reference:
Patent; NOVARTIS AG; FURET, Pascal; KALTHOFF, Frank Stephan; MAH, Robert; RAGOT, Christian; STAUFFER, Frederic; WO2010/139731; (2010); A1;,
Pyrazole – Wikipedia,
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