35344-95-7,Some common heterocyclic compound, 35344-95-7, name is 1H-Pyrazole-4-carbaldehyde, molecular formula is C4H4N2O, 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.
To the stirred solution of cyclopentyl methanesulfonate 6-3 (380 mg, 2.31 mmol) in DMF (2 mL) was added lH-pyrazole- 4-carbaldehyde 6-4 (266.81 mg, 2.78 mmol) and cesium carbonate (1.51 g, 4.63 mmol) at 0C. The reaction was heated at 80C for 16 hours and then diluted with ice cold water, extracted with ethyl acetate, washed with brine, dried over sodium sulfate, and concentrated under reduced pressure. The crude material was purified by flash chromatography using Q%~3()% ethyl acetate/hexane to afford -cyciopentylpyrazole-4-carbaldehyde 5 (280 mg, 1.71 mmol, 73.69% yield) as a brown liquid. H I NMR (400 MHz, DMSO-d6) 6 9.77 (s, 1 1 1), 8.50 (s, 1 1 1 ), 7.98 (s, lH), 4 80-4 73 (m, 1H), 2.13-2.05 (m, 2H), 1 98-1.87 (m, 2H), 1.83-1.77 (m, 21 1), 1.69-1.67 (m, 2H).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 1H-Pyrazole-4-carbaldehyde, its application will become more common.