Related Products of 1150271-23-0, These common heterocyclic compound, 1150271-23-0, name is tert-Butyl 4-bromo-1H-pyrazole-1-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.
In the reaction kettle, adding tetrahydrofuran 4.5 kg and 1 – BOC – 4 – brompyrazole (2.01 kg, 9.2 muM), stirring 0.5 hours, cooling to -20 C, maintain -10 C -0 C dropwise 3.2molBu3MgLi [preparation method: 1.0eq butyl magnesium chloride in -10 C -0 C lower drop by adding 2.0 equivalent butyl lithium in], TLC detection reaction, maintain the exchange completion -10 C -0 C dropwise dimethylamine fundamental frequency that mellow boron ester (1.61 kg, 9.4 muM) dissolved in 1 kg of the mixed solution in tetrahydrofuran, the completion of the dropping, thermal insulation 2 hours, natural heating stirring overnight. The control temperature of not more than 30 C after adding glacial acetic acid, after detecting the protecting group removal, stop stirring filtration, the mother liquor recovered, solid add triethylamine (1.01 kg, 10 muM) and ethyl acetate 8 kg after, heating to reflux reaction, the proportion of internal standard detecting product is not increased when, after lowering the filtering, the filtrate obtained after the distillation is a kind of white solid, by adding heptane cooling to 0 C beating, filtering, 50 – 60 C vacuum drying to obtain white solid pyrazole -4 – boric acid frequency that alcohol ester 1.36 kg, GC: 99.1%, HNMR consistent with the literature value, yield 76%.
The synthetic route of 1150271-23-0 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Cangzhou Puri Oriental Technology Co., Ltd; Leng, Yanguo; Gui, Qian; Shen, Haibing; (5 pag.)CN106188116; (2016); A;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics