Some common heterocyclic compound, 3994-50-1, name is 1-Methyl-4-nitro-1H-pyrazole, molecular formula is C4H5N3O2, 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. Formula: C4H5N3O2
Example 25Synthesis of 4-[2-(difluoromethyl)-1H-benzimidazol-1-yl]-N-(1-methyl-1H-pyrazol-4-yl)-6-(4-morpholinyl)-1,3,5-triazin-2-amineThe compound was synthesized according to Method A.A mixture of 0.996 g (8.82 mmol) of 4-nitropyrazole (J. Med. Chem. 2005, 48, 5780-5793) and 1.33 g (10.6 mmol) of dimethyl sulphate in 10 mL of 1 M NaOH was heated at 35 C. for 48 hrs. The reaction mixture was cooled to RT and the precipitate was filtered, washed with water, and dried to give 0.561 g (50% yield) of 1-methyl-4-nitro-1H-pyrazole: 1H NMR (DMSO-d6) delta8.83 (s, 1H), 8.22 (s, 1H), 3.91 (s, 3H).A mixture of 0.144 g (1.14 mmol) 1-methyl-4-nitro-1H-pyrazole, 0.017 g (0.07 mmol) platinum oxide, and ethyl acetate (5 mL) in ethanol (15 mL) was stirred under 2 atmospheres of hydrogen for 14 hrs. The catalyst was removed by filtration through a pad of celite and the solvent was removed to give 0.080 mg (73% yield) of 4-amino-1-methyl-1H-pyrazole as a purple residue, which was used in the next step without further purification: 1H NMR (DMSO-d6) delta6.98 (s, 1H), 6.88 (s, 1H), 3.76 (br s, 2H), 3.65 (s, 3H).A mixture of 0.405 g (4.27 mmol) of 4-amino-1-methylpyrazole and 0.695 g (1.90 mmol) of 1-[4-chloro-6-(4-morpholinyl)-1,3,5-triazin-2-yl]-2-(difluoromethyl)-1H-benzimidazole in DMSO (5 mL) was heated at 125 C. for 15 min. The reaction mixture was cooled to room temperature and water was added. The solid was collected by filtration, washed with water, and dried. Chromatography on alumina, eluting with hexanes/EtOAc (1:1) gave a brown powder. Recrystallization from ethanol/CH2Cl2 gave 0.145 g (18% yield) of 4-[2-(difluoromethyl)-1H-benzimidazol-1-yl]-N-(1-methyl-1H-pyrazol-4-yl)-6-(4-morpholinyl)-1,3,5-triazin-2-amine: mp 225-226 C.; 1H NMR (DMSO-d6) (rotamers) delta10.00 (s, 1H), 9.73 (s, 0.2H), 8.60 (d, J=8.0 Hz, 1H), 8.29 (d, J=7.6 Hz, 0.2H), 7.92 (t, JHF=52.8 Hz, 1H), 7.86-7.80 (m, 2.6H), 7.68 (t, JHF=52.6 Hz, 0.2H), 7.59 (s, 1H), 7.52-7.42 (m, 2.9H), 3.85-3.82 (m, 8.4H), 3.75-3.73 (m, 4.8H); Anal. Calcd. for C19H19F2N9O 0.06EtOAc 0.24H2O: C, 52.9; H, 4.6; N, 28.8. Found: C, 52.9; H, 4.5; N, 28.6%.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 3994-50-1, its application will become more common.
Reference:
Patent; Pathway Therapeutics Limited; US2011/9405; (2011); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics