The synthetic route of 138786-86-4 has been constantly updated, and we look forward to future research findings.
Related Products of 138786-86-4, These common heterocyclic compound, 138786-86-4, name is Methyl 4-nitro-1H-pyrazole-3-carboxylate, 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.
A solution of methyl 4-nitro-lH-pyrazole-3 -carboxylate (54.Og, 315.6 mmol), phenylboronic acid (77.Og, 631.2 mmol), copper(JJ) acetate (86.Og, 473.4 mmol) and pyridine (49.9g,631.2 mmol) in methylene chloride (600 mL) was stirred at ambient temperature open to air for 48 hours. The reaction was evaporated in vacuo, diluted with 1 L of methylene chloride and filtered through a large plug of silica (washing with 2 L methylene chloride). The solvent was evaporated in vacuo to give methyl 4-nitro-l -phenyl- lH-pyrazole-3 -carboxylate confirmed by 1HNMR (CDCl3) delta 8.61 (s, IH), 7.73 (m, 2H), 7.50 (m, 3H), 4.02 (s, 3H). A solution of methyl 4-nitro-l-phenyl-lH-pyrazole-3-carboxylate (78.1 g, 315.9 mmol) in THF (600 mL) was treated with 4M potassium hydroxide (79mL, 316 mmol) dropwise and the solution was stirred at ambient temperature for 16 hours. The reaction was evaporated in vacuo and acidified with 6M HCl. After addition of water (500 mL) the solids were filtered off and dried to give 4- nitro-1 -phenyl- lH-pyrazole-3-carboxylic acid as a grayish solid confirmed by 1H NMR (CD3OD) delta 9.37 (bs, IH), 7.88 (m, 2H), 7.59 (m, 2H), 7.44 (m, IH).A solution of 4-nitro-l-phenyl-lH-pyrazole-3-carboxylic acid (20.0 g, 85.8 mmol), triethylamine (36.0 mL, 257.3 mmol), and diphenylphosphoryl azide (37.8 g, 137.2 mmol) in dioxane (400 mL) and tert-butanol (200 mL) was heated to reflux for 16 hours. The reaction was evaporated to dryness in vacuo, diluted with methylene chloride (400 mL) and treated with trifluoroacetic acid (128 g, 857.7 mmol). The solution was stirred at ambient temperature for 16 hours. The reaction was evaporated in vacuo and the resulting oil diluted with hexanes (750 mL), ethyl acetate (150 mL) and methylene chloride (100 mL). The solids were filtered, washed with above solvent system (hexanes: ethyl acetate;methylene chloride 75:15:10), and dried to give the 4-nitro-l -phenyl- lH-pyrazol- 3-amine product as a yellow solid confirmed by 1H NMR (CDCl3) delta 8.43 (s, IH), 7.62 (m, 2H), 7.48 (m, 2H), 7.37 (m, IH).A mixture of the nicotinic acid (159 mg, 0.447 mmol) and BOP (233 mg, 0.528 mmol) in DMF (1.5 mL) was stirred vigorously for 1 hour at room temperature and then a mixture of 4-nitro-l- phenyl-lH-pyrazol-3-amine (83 mg, 0.406 mmol) and NaH (49 mg, 2.03 mmol) in DMF (1.5 mL) was added dropwise. After 12 hours of stirring at room temperature the reaction mixture was filtered over Celite, concentrated and purified by flash chromatography (10-80% EtOAc/hexanes). Formation of the pyrazolyl nitro-nicotinamide was confirmed by MS (ESI+): cal’d [M+H]+ 542.2, exp. 542.2. To a solution of the pyrazolyl nitro-nicotinamide in MeOH (3 mL) was added PtO2 (5 mg, 0.02 mmol). After 30 minutes of stirring at room temperature under an atmosphere OfH2, the reaction mixture was filtered over Celite, concentrated, and purified by reverse-phase chromatography (15-75% MeCNTH2O with 0.05% TFA) to give the desired pyrazolyl nicotinamide after the standard sat’d aq. NaHCO3 wash confirmed by:1HNMR (600 MHz, CD3OD) delta 8.78 (d, J = 2.1 Hz, IH), 8.42 (s, IH), 8.19 (dd, J = 9.1 Hz, 2.1 Hz, IH), 7.77 (d, J = 7.9 Hz, 2H), 7.49 (t, J = 7.9 Hz, 2H), 7.41-7.28 (m, 6H), 6.91 (d, J = 9.4 Hz, IH), 5.17-5.11 (m, 2H), 4.44-4.37 (m, IH), 4.28-4.22 (m, 2H), 4.00 (d, J = 13.5 Hz, IH), 3.43 (dd, J = 13.5, 3.5 Hz, IH), 3.37 (t, J = 10.8 Hz, IH), 3.23- 3.16 (m, IH), 1.18 (d, J = 6.5 Hz, 3H); MS (ESI+): cal’d [M+H]+ 512.2, exp. 512.2.
The synthetic route of 138786-86-4 has been constantly updated, and we look forward to future research findings.