Adding a certain compound to certain chemical reactions, such as: 16034-46-1, name is 1-Methyl-1H-pyrazole-5-carboxylic acid, belongs to pyrazoles-derivatives compound, can increase the reaction rate and produce products with better performance than those obtained under traditional synthetic methods. Here is a downstream synthesis route of the compound 16034-46-1, Application In Synthesis of 1-Methyl-1H-pyrazole-5-carboxylic acid
To a solution of tert-butyl [2-(3,5-difluorobenzyl)-4-methyl-1,3-thiazol-5-yl]carbamate (300 mg, 0.881 mmol) obtained in Example 220-D) in ethanol (2 mL) was added dropwise concentrated hydrochloric acid (0.630 mL) at room temperature, and the mixture was stirred at 50C for 3.5 hr. The reaction mixture was cooled to 0C, neutralized with 8N aqueous sodium hydroxide solution, adjusted to pH 10-11 with saturated aqueous sodium hydrogen carbonate solution, and extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The obtained residue was dissolved in DMA (8 mL), and 1-methyl-1H-pyrazole-5-carboxylic acid (134 mg, 1.06 mmol), HATU (403 mg, 1.06 mmol) and DIEA (0.0728 mL, 0.441 mmol) were added at room temperature. The reaction mixture was stirred at 60C for 3.5 hr, cooled to room temperature, water and 0.1N hydrochloric acid were added and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated aqueous sodium hydrogen carbonate solution and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography [eluent: hexane-ethyl acetate (3:2-3:7)] and basic silica gel column chromatography [eluent: hexane-ethyl acetate (3:2-3:7)], and crystallized from ethyl acetate-hexane to give the title compound (144 mg) as colorless crystals (yield 47%). MS (ESI+): [M+H]+ 349. 1H NMR (300 MHz, DMSO-d6) delta 2.31 (3H, s), 4.05 (3H, s), 4.26 (2H, s), 7.04-7.17 (4H, m), 7.54 (1H, d, J = 2.3 Hz), 10.53 (1H, s).
At the same time, in my other blogs, there are other synthetic methods of this type of compound, 1-Methyl-1H-pyrazole-5-carboxylic acid, and friends who are interested can also refer to it.