Reference of 37687-18-6, These common heterocyclic compound, 37687-18-6, name is 1-(1-Methyl-1h-pyrazol-4-yl)-ethanone, 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.
B. Synthesis of 2-bromo-1-(1-methyl-1H-pyrazol-4-yl)ethanone A solution of 1-(1-methyl-1H-pyrazol-4-yl)ethanone (28.5 g, 230 mmol) in dichloromethane (400 mL) was diluted with absolute ethanol (100 mL) and treated portion-wise with pyridinium tribromide (95%, 77.3 g, 230 mmol). The reaction was stirred at room temperature for 3 hours, during which time it solidified; the mixture was diluted with dichloromethane (300 mL) and water (400 mL), treated with sodium sulfite (5 g) and stirred for 10 minutes. The organic layer was dried over magnesium sulfate, filtered and concentrated in vacuo. The residue was washed with water (200 mL), collected by filtration, washed again with water, and dried to afford the product as an off-white solid. Yield: 41.6 g, 205 mmol, 89%. 1H NMR (500 MHz, CDCl3) delta 7.97-7.98 (m, 1H), 7.95 (br s, 1H), 4.17 (s, 2H), 3.95-3.96 (m, 3H).
Statistics shows that 1-(1-Methyl-1h-pyrazol-4-yl)-ethanone is playing an increasingly important role. we look forward to future research findings about 37687-18-6.
Reference:
Patent; Pfizer Inc.; US2012/214791; (2012); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics