Reference of 175137-46-9, These common heterocyclic compound, 175137-46-9, name is 5-Cyclopropyl-1H-pyrazol-3-amine, 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 l,2,3,4-tetrafluoro-5-nitrobenzene (3.0 g, 15.4 mmol) and DIEA (3.7 ml, 21.0 mmol) in dry THF (20 ml) was added S-cyclopropyl-l/f-pyrazol-S-amine (1.7 g, 14.0 mmol) in THF (5 ml) drop wise at 0 C. After addition, the reaction mixture was stirred at 25 C for 16 hours. The solvent was removed under reduced pressure and the resulted residue was purified by column chromatography (hexane-EtOAc = 4 : 1). This was recrystalized from Et2O (20ml) and hexanes (~150ml) to give the title compound as red crystals (0.650 g, 16%). 1H NMR (400 MHz) 11.84 (s, IH), 8.67 (s, IH), 8.06 (m, IH), 5.57 (s, IH), 1.82 (m, IH), 0.89 (m, 2H), 0.65 (m, 2H). MS: Calcd.: 298; Found: [M+H]+ 299.
Statistics shows that 5-Cyclopropyl-1H-pyrazol-3-amine is playing an increasingly important role. we look forward to future research findings about 175137-46-9.
Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2006/87530; (2006); A1;,
Pyrazole – Wikipedia,
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