Synthetic Route of 920006-32-2, These common heterocyclic compound, 920006-32-2, name is 1-Isopropylpyrazole-5-carboxylic Acid, 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.
tert-Butyl [2-(3-chloro-5-fluorobenzyl)-4-methyl-1,3-thiazol-5-yl]carbamate (240 mg, 0.67 mmol) obtained in Example 145-E) was dissolved in 12M hydrochloric acid (1 mL) and ethanol (1 mL), and the mixture was stirred at room temperature for 1 hr. The reaction mixture was concentrated under reduced pressure, basified with saturated aqueous sodium hydrogen carbonate solution, and extracted with ethyl acetate. The extract was dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was dissolved in DMF (2 mL), 1-(1-methylethyl)-1H-pyrazole-5-carboxylic acid (104 mg, 0.67mmol)), HATU (307 mg, 0.81 mmol) and DIEA (0.058 mL, 0.34 mmol) were added at room temperature, and the mixture was stirred at 60C for 3 hr. The reaction mixture was diluted with saturated aqueous sodium hydrogen carbonate solution, and extracted with ethyl acetate. The extract was washed with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography [eluent: hexane-ethyl acetate (90:10-50:50)] to give the title compound (130 mg) as a pale-brown powder (yield 49%). MS (ESI+): [M+H]+ 393. 1H NMR (300 MHz, CDCl3) delta 1.51 (6H, d, J = 6.8 Hz), 2.40 (3H, s), 4.20 (2H, s), 5.30-5.65 (1H, m), 6.64 (1H, d, J = 2.3 Hz), 6.87-7.05 (2H, m), 7.11 (1H, s), 7.57 (1H d, J = 1.9 Hz), 7.72 (1H, brs).
The synthetic route of 920006-32-2 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Takeda Pharmaceutical Company Limited; EP2530078; (2012); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics