Some common heterocyclic compound, 1192-21-8, name is 1-Methyl-1H-pyrazol-5-amine, molecular formula is C4H7N3, 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. category: pyrazoles-derivatives
Procedure NA mixture of an appropriate amine or aniline, respectively (1.0 mmol), an appropriate carbox- ylic acid (1.0 mmol), HBTU (1.0 mmol), a catalytic amount of 4-dimethylaminopyridine (DMAP), iV-ethyldiisopropylethylamine (1.25 mmol), and dry dichloromethane (2 mL) was stirred at room temperature for 12-48 h. The solvent was evaporated under reduced pressure. The residue was taken up with EtOAc (25 mL) and washed with 5 percent citric acid, water, saturated aqueous NaHCO3 solution, and brine. After drying (MgSO4), the solvent was removed under reduced pressure. The product was purified by preparative TLC, flash chromatography, or preparative HPLC. Purity was confirmed by 1H NMR and LC/ESIMS.For the synthesis of Example 145, gaseous ammonia was introduced into the reaction mixture. No additional amine base was applied.For the synthesis of Example 146, methylammonium chloride was applied as the amine, and the amount of amine base was increased to 2.5 mmol.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 1192-21-8, its application will become more common.
Reference:
Patent; QUONOVA LLC; WO2009/77844; (2009); A2;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics