Some common heterocyclic compound, 2075-45-8, name is 4-Bromo-1H-pyrazole, molecular formula is C3H3BrN2, 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. name: 4-Bromo-1H-pyrazole
A mixture of 4-bromo-1H-pyrazole, 3,4-hydro- 2H-pyran (128 g, 1.50 mol, 1.5 eq) and trifluoroacetic acid (7.8 mL, 0.10 mol, 0.1 eq) was stirred at 80 C for 16 h. Progress of the reaction was monitored by TLC (10% ethyl acetate- hexane Rf = 0.4). After completion of the reaction, the reaction mixture was diluted with ethyl acetate and was washed with saturated aqueous sodium bicarbonate and brine. The organic layer was dried over anhydrous sodium sulfate, filtered and the solvents were evaporated under reduced pressure to obtain 4-bromo-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole (180 g, 76%) as a brown oil. LCMS purity: 81.4%; (ES+): m/z 231.2 (M+H+); tr = 1.88 min.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2075-45-8, its application will become more common.
Reference:
Patent; INNOV17 LLC; GAWECO, Anderson; TILLEY, Jefferson; BLINN, James; (148 pag.)WO2016/14913; (2016); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics