In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 13808-64-5, name is 4-Bromo-3-methylpyrazole belongs to pyrazoles-derivatives compound, it is a common compound, a new synthetic route is introduced below. HPLC of Formula: C4H5BrN2
NaH (60% in mineral oil, 410 mg, 10.2 mmol) is added portionwise to a stirred solution of 4- bromo-3-methylpyrazole (1.69 g, 10.2 mmol) in DMF (20 ml). The resulting mixture is stirred for 1 h at 00C and 4-Methanesulfonyloxy-piperidine-1-carboxylic acid tert-butyl ester (as obtained in preparation 61 , 2.839 g, 10.16 mmol) is added. The resulting pale suspension is heated at 950C for 1h. The reaction is quenched with water and extracted with EtOAc several times. The combined organic layers are washed with brine, dried over Na2SO4, filtered and the filtrate is concentrated in vacuo. The residue is purified by chromatography on a 120 g silica gel column on a Combiflash Companion (Isco Inc.) apparatus ( gradient hexanes: TBDME from 1 :0 => 1 :1) to afford the two regioisomers identified by preparation 92 and preparation 93.
The synthetic route of 13808-64-5 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; NOVARTIS AG; WO2008/148867; (2008); A2;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics