Application of 25016-17-5, These common heterocyclic compound, 25016-17-5, name is Methyl 5-methyl-1H-pyrazole-3-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.
To 1.2 g of a mixture of acids 8 and 9 obtained in the previous synthesis 5 mL of acetic anhydride was added, the mixture was stirred for 4 hours at boiling and left overnight. The precipitated crystals in the form of fine colorless needles were filtered off and washed with acetic acid. Yield 452 mg (41%), mp 144-145C. The acetic anhydride contained in the mother liquor was hydrolyzed with water. The precipitated crystals were filtered off, washed with water and after drying recrystallized from methanol. Additionally, 101 mg of the reaction product were obtained, total yield 50%. IR spectrum, nu, cm-1: 1730(CO), 1630 (Ph). 1H NMR spectrum, delta, ppm: 2.41 s(3H, CH3), 6.97 s (1H, CH), 7.41 t (1H, Ph, J 7.2 Hz),7.45 t (2H, Ph, J 7.2 Hz), 7.82 d (2H, Ph, J 7.6 Hz),8.50 s (1H,CH). 13 NMR spectrum, delta, ppm: 15.3(CH3), 109.1 (CH), 109.5 (CH), 126.1 (Ph), 128.8,130.6 (Ph), 131.2 (Ph), 131.7 (Ph), 143.6, 152.9, 154.8(CO). Found, %: C 64.98; H 4.48; N 12.40.13H10N2O2. Calculated, %: C 65.02; H 4.46; N 12.38.
Statistics shows that Methyl 5-methyl-1H-pyrazole-3-carboxylate is playing an increasingly important role. we look forward to future research findings about 25016-17-5.