5334-43-0, A common heterocyclic compound, 5334-43-0, name is 5-Amino-1-phenyl-1H-pyrazole-4-carbonitrile, molecular formula is C10H8N4, 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.
1.0 g of compound (2) is added to 10 ml of phosphoric acid (Wako Pure Chemical Industries, Ltd.; special grade reagent; purity: 85%; hereinafter the same), and is heated to 30C to dissolve. This solution is ice-cooled to keep the temperature to 0 to 5C, and 0.38 g of sodium nitrite is added thereto, followed by stirring for 1.5 hours to obtain a diazonium salt solution. This diazonium salt solution is dropwise added to a solution of 1.4 g of compound (0) in 5 ml of dimethylacetamide while keeping the temperature at 5 to 10C, followed by stirring for 1 hour while keeping the temperature at 5 to 10C. Thereafter, the ice bath is removed, and stirring is continued for further 0.5 hour. 50 ml of ethyl acetate is added to the reaction solution, and the resulting mixture is heated at 80C to completely dissolve. To the reaction solution is added 50 ml of hexane, followed by stirring at 80C for 20 minutes, then at room temperature for 40 minutes. Crystals precipitated are collected by filtration, and spray-washed with 50 ml of hexane. To the thus-obtained crystals are added, without drying, 200 ml of water and 0.1 ml of saturated sodium hydrogencarbonate to neutralize. 100 ml of acetonitrile is added to the crystals, followed by stirring at 80C for 3 hours, then at room temperature for 1 hour. Crystals precipitated are collected by filtration, and spray-washed with 50 ml of acetonitrile. The thus-obtained crystals are dried to obtain 0.51 g of compound D-33 of the invention. Yield: 21%. lambda?,alphachi: 504 nm, x 104 (CHC13)Infrared absorption chart is shown in Fig. 2.
The synthetic route of 5-Amino-1-phenyl-1H-pyrazole-4-carbonitrile has been constantly updated, and we look forward to future research findings.