Reference of 5203-77-0,Some common heterocyclic compound, 5203-77-0, name is 1,3-Dimethyl-1H-pyrazol-5-ol, molecular formula is C5H8N2O, 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.
General procedure: Intermediate 7 (4mmol), dissolved in dry dichloromethane (60mL), and PCl5 (4.2mmol) were added and stirred at room temperature for 1h. The solvent was moved out under reduced pressure to afford acid chloride, the acid chloride was then dissolved in dry CH2Cl2 (60mL), Then 1-methyl-1H-pyrazol-5-ol (4mmol) and Et3N (4.8mmol) were added to the above solution, and stirred for a further 18-24hat room temperature. After adding dichloromethane (30mL), the resultant mixture was washed sequentially with 2N hydrochloric acid (100mL), saturated NaHCO3 and saturated NaCl and dried over Na2SO4. The rest of the solution was evaporated in vacuum and purified by silica gel column chromatography using gradient elution of ethyl acetate/hexane (V:V = 1:2) to obtain the desired intermediate 8 as a write powder (30%-70%). 4.1.10 1-methyl-1H-pyrazol-5-yl3-methyl-2-oxo-1-propyl-2,3-dihydro-1H-benzo[d] imidazole- 5-carboxylate Yield: 45%. m.p. 107-108C. 1H NMR (600MHz, CDCl3) delta 8.01 (dd, J=8.4, 1.2Hz, 1H), 7.77 (d, J=1.2Hz, 1H), 7.48 (d, J=1.8Hz, 1H), 7.10 (d, J=8.4Hz, 1H), 6.20 (d, J=1.8Hz, 1H), 3.92 (t, J=7.2Hz, 2H), 3.80 (s, 3H), 3.51 (s, 3H), 1.91-1.71 (m, 2H), 1.00 (t, J=7.8Hz, 3H). EI-MS (m/z): 314.18 (M)+.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 1,3-Dimethyl-1H-pyrazol-5-ol, its application will become more common.