Some common heterocyclic compound, 1192-21-8, name is 1-Methyl-1H-pyrazol-5-amine, molecular formula is C4H7N3, 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. Formula: C4H7N3
1-Methyl-1H-pyrazol-5-amine (4.85 g, 49.9 mmol) and diethylethoxymethylenemalonate (10 mL, 50 mmol) were heated at110 C for 1.5 h. The ethanol by-product was removed by evaporationunder reduced pressure. Phosphoryl trichloride (12.1 mL,130 mmol) was added and the mixture was heated at 110 C for3.5 h. The mixture was cooled to room temperature and MeCN(5 mL) was added, and then the solution was further cooled downto 10 C. Water (80 mL) was added slowly maintaining the temperaturebelow 10 C and the suspension was stirred at ambient temperatureovernight. The resultant solid was collected by filtration,washed with minimum amount of water and dried under reducedpressure to afford the title compound (6.7 g, 54percent) as a white solid;1H NMR (400 MHz, DMSO-d6) d = 8.96 (s, 1H), 8.40 (s, 1H), 4.38 (q,J = 7.0 Hz, 2H), 4.10 (s, 3H), 1.36 (t, J = 7.0 Hz, 3H); 13C NMR(101 MHz, DMSO-d6) d = 163.6, 151.0, 150.7, 137.8, 132.2, 118.0,115.1, 61.5, 34.2, 14.0. LCMS (Method A, UV, ES): RT = 1.00 min,[M+H]+ = 240, 242, 97percent purity. These data were in agreement withthose reported in the literature.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 1192-21-8, its application will become more common.