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CAS No. : | 7119-95-1 | MDL No. : | MFCD00015894 |
Formula : | C3H3N3O2 | Boiling Point : | No data available |
Linear Structure Formula : | - | InChI Key : | TYNVOQYGXDUHRX-UHFFFAOYSA-N |
M.W : | 113.07 | Pubchem ID : | 146002 |
Synonyms : |
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Signal Word: | Warning | Class: | |
Precautionary Statements: | P261-P305+P351+P338 | UN#: | |
Hazard Statements: | H302-H315-H319-H335 | Packing Group: | |
GHS Pictogram: |
* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
92% | With nitric acid; acetic anhydride; In acetic acid; at 55℃;Cooling with ice; Flow reactor; High pressure; | The acetic anhydride and fuming nitric acid are slowly mixed in an ice water bath at a volume ratio of 5.5:1 to obtain a nitrating agent, and the nitratingagent and the pyrazole acetic acid solution are respectively delivered to the microchannel reactor through a high-pressure constant-flow pump with precise flow control. The twoinlets control the molar ratio of nitric acid to pyrazole to be 1.1:1. At 45-70 °C, the two liquids are instantaneously mixed in the microchannel reactorand reacted. The reaction solution is poured into crushed ice and filtered. It was washed with ice water and dried under vacuum to give N-nitropyrazole; theflow rate of the acetic acid solution of the pyrazole was 0.1 mL/min.The yield and purity of N-nitropyrazole are shown in Table 1 and Figure 2. |
78% | Fuming nitric acid (3.3 mL) was added dropwise to a stirred solution of pyrazole (4.5 g, 66 mmol) in glacial acetic acid (14.1 mL) that had been cooled to ?10 °C using an ice-salt bath. A voluminous precipitate was formed. Acetic anhydride (9.45 mL) was added dropwise and the resultant mixture was stirred at ambient temperature for 1.5 h. The mixture was poured onto ice and was neutralized with potassium carbonate. The precipitate was isolated by filtration. The yield of the obtained white solid of N-nitropyrazole is 78percent. | |
The 4-arnino-l-methyl-lH-pyrazole used as a starting material was prepared as follows :-4-Nitropyrazole is available commercially from the N.D. Zelinsky Institute, Organic Chemistry, Leninsky prospect 47, 117913 Moscow B-334, Russia. The compound may also be 5 prepared as follows :-Fuming nitric acid (9.5 ml) was added dropwise to a stirred solution of pyrazole (13.6 g) in glacial acetic acid (51 ml) that had been cooled to -10°C using an ice-salt bath. A voluminous precipitate was formed. Acetic anhydride (27 ml) was added dropwise and the resultant mixture was stirred at ambient temperature for 2.5 hours. The mixture was poured10 onto ice and the acidity of the mixture was reduced to pEta5 by the addition of potassium carbonate. The precipitate was isolated by filtration. The resultant solid was dissolved in water and the aqueous solution was extracted with diethyl ether. The organic solution was dried over magnesium sulphate and filtered. Petroleum ether (b.p. 60-80°C, 50 ml) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate15 formed which was isolated by filtration. This solid was believed to be 1-nitropyrazole(20.6 g); 1H NMR: (DMSOd6) 6.71 (s, IH), 7.88 (s, IH), 8.81 (s, IH). |
4-Nitropyrazole is available commercially from the N.D. Zelinsky Institute, Organic Chemistry, Leninsky prospect 47, 117913 Moscow B-334, Russia. The compound may also be prepared as follows :- s Fuming nitric acid (9.5 ml) was added dropwise to a stirred solution of pyrazole(13.6 g) in glacial acetic acid (51 ml) that had been cooled to -100C using an ice-salt bath. A voluminous precipitate was formed. Acetic anhydride (27 ml) was added dropwise and the resultant mixture was stirred at ambient temperature for 2.5 hours. The mixture was poured onto ice and the acidity of the mixture was reduced to pH5 by the addition of potassium 0 carbonate. The precipitate was isolated by filtration. The resultant solid was dissolved in water and the aqueous solution was extracted with diethyl ether. The organic solution was dried over magnesium sulphate and filtered. Petroleum ether (b.p. 60-80°C, 50 ml) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate formed which was isolated by filtration. This solid was believed to be S 1-nitropyrazole (20.6 g); 1H NMR: (DMSOd6) 6.71 (s, IH), 7.88 (s, IH), 8.81 (s, IH). The compound may be explosive and should be handled cautiously. | ||
With nitric acid; acetic anhydride; acetic acid; at -10 - 25℃; for 2.5h; | Fuming nitric acid (9.5 ml) was added drop wise to a stirred solution of pyrazole (13.6 g) in glacial acetic acid (51 ml) that had been cooled to -1O0C using an ice-salt bath. A voluminous precipitate was formed. Acetic anhydride (27 ml) was added dropwise and the resultant mixture was stirred at ambient temperature for 2.5 hours. The mixture was poured onto ice and the acidity of the mixture was reduced to pH5 by the addition of potassium carbonate. The precipitate was isolated by filtration. The resultant solid was dissolved in water and the aqueous solution was extracted with diethyl ether. The organic solution was dried over magnesium sulphate and filtered. Petroleum ether (b.p. 60-80°C, 50 ml) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate formed which was isolated by filtration. This solid was believed to be 1-nitropyrazole (20.6 g); 1HNMR: (DMSOd6) 6.71 (s, IH), 7.88 (s, IH), 8.81 (s, IH). | |
Fuming nitric acid (9.5 ml) was added drop wise to a stirred solution of pyrazole (13.6 g) in glacial acetic acid (51 ml) that had been cooled to -10°C using an ice-salt bath. A voluminous precipitate was formed. Acetic anhydride (27 ml) was added dropwise and the resultant mixture was stirred at ambient temperature for 2.5 hours. The mixture was poured onto ice and the acidity of the mixture was reduced to rhoH5 by the addition of potassium carbonate. The precipitate was isolated by filtration. The resultant solid was dissolved in water and the aqueous solution was extracted with diethyl ether. The organic solution was dried over magnesium sulphate and filtered. Petroleum ether (b.p. 60-800C, 50 ml) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate formed which was isolated by filtration. This solid was believed to be1-nitropyrazole (20.6 g); 1H NMR: (DMSOd6) 6.71 (s, IH), 7.88 (s, IH), 8.81 (s, IH). The compound may be explosive and should be handled cautiously. | ||
The compound may also be prepared as follows:- Fuming nitric acid (9.5 ml) was added dropwise to a stirred solution of pyrazole (13.6 g) in glacial acetic acid (51 ml) that had been cooled to -10° C. using an ice-salt bath. A voluminous precipitate was formed. Acetic anhydride (27 ml) was added dropwise and the resultant mixture was stirred at ambient temperature for 2.5 hours. The mixture was poured onto ice and the acidity of the mixture was reduced to pH5 by the addition of potassium carbonate. The precipitate was isolated by filtration. The resultant solid was dissolved in water and the aqueous solution was extracted with diethyl ether. The organic solution was dried over magnesium sulphate and filtered. Petroleum ether (b.p. 60-80° C., 50 ml) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate formed which was isolated by filtration. This solid was believed to be 1-nitropyrazole (20.6 g); 1H NMR: (DMSOd6) 6.71 (s, 1H), 7.88 (s, 1H), 8.81 (s, 1H). The compound may be explosive and should be handled cautiously. | ||
With nitric acid; acetic anhydride; acetic acid; at 25℃; for 0.5h; | Freshly prepared acetyl nitrate (HNO3, 1.8 mL, d = 1.54 g cm?3 and acetic anhydride, 4.2 mL) was added to pyrazole (1.0 g) dissolved in acetic acid (2.8 mL) at 25 °C. After stirring for 30 min the reaction mixture was poured into water. The crude yield after washing with water and drying was 1.4 g (84percent). m.p. 91?92 °C. FT-IR (KBr, cm?1): 1617, 1320 (N?NO2). 1H NMR (DMSO-d6) delta: 8.65 (d, 1H, 5-H), 7.80 (s, 1H, 3-H), 6.73 (m, 1H, 4-H). EI-MS: m/z 113 (M+·). Anal. Calcd for C3H3N3O2 (113.08): C, 31.83; H, 2.67; N, 37.26. Found: C, 32.88; H, 2.62; N, 37.43. | |
With nitric acid; In acetic anhydride; acetic acid; at 20 - 30℃; for 2.5h; | A 100mL one-neck flask equipped with a magnetic stirrer was added 5g of compound 1 and 15mL acetic acid, stirred, to give a clear solution. Under ice bath 3.5mL of fuming nitric acid was slowly added dropwise to the mixed solution, maintaining vigorous stirring, the reaction temperature does not exceed 30 deg. C. 10mL acetic anhydride was added to the mixture, after the addition, the mixture immediately became cloudy, to give a white turbid liquid. After the addition it was stirred at room temperature, until the solution became clear, about 2.5h. After completion of the reaction, the solution was slowly poured into 100mL crushed ice and with vigorous stirring, potassium carbonate was added portionwise until the mixture was neutral, white precipitate was filtered to give 5.6g of white powdery crystals, the filtrate was extracted with ethyl acetate, the combined organic phase was dried over anhydrous sodium sulfate, the solvent was removed by rotary evaporation to give pale yellow crystals 1.3490g, total crude was 6.9490g, yield 91.9percent recrystallized from benzene. Weigh three 100mg compound 2 into thick-walled pressure bottle, gradually heated to 160 deg. C, 180 deg. C, 200 deg. C, the reaction at this temperature for 1 ~ 3h to obtain compound 3, the results shown in Table 1. | |
The 4-amino-l -ethyl- lH-pyrazole used as a starting material was prepared as follows :; -4-Nitropyrazole is available commercially from the N.D. Zelinsky Institute, Organic Chemistry, Leninsky prospect 47, 117913 Moscow B-334, Russia. The compound may also be prepared as follows :; -Fuming nitric acid (9.5 ml) was added drop wise to a stirred solution of pyrazole (13.6 g) in glacial acetic acid (51 ml) that had been cooled to -100C using an ice-salt bath. A voluminous precipitate was formed. Acetic anhydride (27 ml) was added dropwise and the resultant mixture was stirred at ambient temperature for 2.5 hours. The mixture was poured onto ice and the acidity of the mixture was reduced to pH5 by the addition of potassium carbonate. The precipitate was isolated by filtration. The resultant solid was dissolved in water and the aqueous solution was extracted with diethyl ether. The organic solution was dried over magnesium sulphate and filtered. Petroleum ether (b.p. 60-80°C, 50 ml) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate formed which was isolated by filtration. This solid was believed to be 1-nitropyrazole (20.6 g); 1H NMR Spectrum: (DMSOd6) 6.71 (s, IH), 7.88 (s, IH), 8.81 (s, IH). | ||
4-Nitropyrazole is available commercially from the N.D. Zelinsky Institute, Organic Chemistry, Leninsky prospect 47, 117913 Moscow B-334, Russia. The compound may also be prepared as follows :-; Fuming nitric acid (9.5 ml) was added drop wise to a stirred solution of pyrazole (13.6 g) in glacial acetic acid (51 ml) that had been cooled to -10°C using an ice-salt bath. A voluminous precipitate was formed. Acetic anhydride (27 ml) was added dropwise and the resultant mixture was stirred at ambient temperature for 2.5 hours. The mixture was poured onto ice and the acidity of the mixture was reduced to peta5 by the addition of potassium carbonate. The precipitate was isolated by filtration. The resultant solid was dissolved in water and the aqueous solution was extracted with diethyl ether. The organic solution was dried over magnesium sulphate and filtered. Petroleum ether (b.p. 60-800C, 50 ml) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate formed which was isolated by filtration. This solid was believed to be 1-nitropyi-azole (20.6 g); 1H NMR Spectrum: (DMSOd6) 6.71 (s, IH), 7.88 (s, IH), 8.81 (s, IH). The compound may be explosive and should be handled cautiously. |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
With sulfuric acid; at -10 - 20℃; | 4-Nitro-lJH-pyrazoIe=N; [547] [Ref: Huettel, R. and Buechele, F., Chem. Ber. 1955, 88, 1586-1590] 1-Nitro-l/Z'-pyrazole (2.2g, 0.019 mol) was dissolved in sulfuric acid (lOmL) at-10°C, and theresulting mixture was slowly warmed to rt overnight. The solution was added to ice (lOOg)dropwise, and the resulting white solid was collected by filtration and washed with water.The aqueous phase was extracted with EtOAc (3x30mL), the combined organic phases werewashed with brine (2x30mL), and dried over anhydrous sodium sulfate. Evaporation underreduced pressure provided an off-white solid, which was combined with the first solid anddried in vacua to provide the title compound. LC-MS (ES, Pos.): 1 14 [MH+]. 'H NMR(DMSO-d6, 400 MHz): 8 = 8.27 (s, 1H), 8.90 (s, 1H), 13.96 (br s, 1H). | |
Concentrated sulphuric acid (80 ml) was added dropwise to a stirred sample of <strong>[7119-95-1]<strong>[7119-95-1]1-nitropyrazol</strong>e</strong> (20.3 g) that was cooled in an ice-bath. The resultant mixture was stirred for20 16 hours and allowed to warm to ambient temperature. The mixture was poured onto ice and stirred for 20 minutes. The resultant solid was isolated and washed with water. The filtrate was neutralised by the addition of potassium carbonate and extracted with diethyl ether. The recovered solid was added to the diethyl ether solution and the resultant solution was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulphate and filtered.25 Petroleum ether (b.p. 60-80°C) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate formed which was isolated by filtration. There was thus obtained 4-<strong>[7119-95-1]nitropyrazole</strong> (16 g); 1HNMR: (DMSOd6 + CF3CO2H) 8.57 (s, 2H). | ||
With sulfuric acid; at 0℃; for 16h; | Concentrated sulphuric acid (80 ml) was added dropwise to a stirred sample of <strong>[7119-95-1]<strong>[7119-95-1]1-nitropyrazol</strong>e</strong> (20.3 g) that was cooled in an ice-bath. The resultant mixture was stirred for 16 hours and allowed to warm to ambient temperature. The mixture was poured onto ice and 0 stirred for 20 minutes. The resultant solid was isolated and washed with water. The filtrate was neutralised by the addition of potassium carbonate and extracted with diethyl ether. The <n="105"/>recovered solid was added to the diethyl ether solution and the resultant solution was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulphate and filtered.Petroleum ether (b.p. 60-80°C) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate formed which was isolated by filtration. There was thus obtained 4-<strong>[7119-95-1]nitropyrazole</strong> (16 g); 1HNMR: (DMSOd6 + CF3CO2H) 8.57 (s,2H). |
With sulfuric acid; at 0 - 25℃; for 16h; | Concentrated sulphuric acid (80 ml) was added dropwise to a stirred sample of <strong>[7119-95-1]<strong>[7119-95-1]1-nitropyrazol</strong>e</strong> (20.3 g) that was cooled in an ice-bath. The resultant mixture was stirred for 16 hours and allowed to warm to ambient temperature. The mixture was poured onto ice and stirred for 20 minutes. The resultant solid was isolated and washed with water. The filtrate was neutralised by the addition of potassium carbonate and extracted with diethyl ether. The recovered solid was added to the diethyl ether solution and the resultant solution was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulphate and filtered. Petroleum ether (b.p. 60-800C) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate formed which was isolated by filtration. There was thus obtained 4-<strong>[7119-95-1]nitropyrazole</strong> (16 g); 1H NMR: (DMSOd6 + CF3CO2H) 8.57 (s, 2H). | |
Concentrated sulphuric acid (80 ml) was added dropwise to a stirred sample of <strong>[7119-95-1]<strong>[7119-95-1]1-nitropyrazol</strong>e</strong> (20.3 g) that was cooled in an ice-bath. The resultant mixture was stirred for 16 hours and allowed to warm to ambient temperature. The mixture was poured onto ice and stirred for 20 minutes. The resultant solid was isolated and washed with water. The filtrate was neutralised by the addition of potassium carbonate and extracted with diethyl ether. The recovered solid was added to the diethyl ether solution and the resultant solution was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulphate and filtered. Petroleum ether (b.p. 60-80°C) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate formed which was isolated by filtration. <n="96"/>There was thus obtained 4-<strong>[7119-95-1]nitropyrazole</strong> (16 g); 1H NMR: (DMSOd6 + CF3CO2H) 8.57 (s, 2H). | ||
Concentrated sulphuric acid (80 ml) was added dropwise to a stirred sample of <strong>[7119-95-1]<strong>[7119-95-1]1-nitropyrazol</strong>e</strong> (20.3 g) that was cooled in an ice-bath. The resultant mixture was stirred for 16 hours and allowed to warm to ambient temperature. The mixture was poured onto ice and stirred for 20 minutes. The resultant solid was isolated and washed with water. The filtrate was neutralised by the addition of potassium carbonate and extracted with diethyl ether. The recovered solid was added to the diethyl ether solution and the resultant solution was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulphate and filtered. Petroleum ether (b.p. 60-80° C.) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate formed which was isolated by filtration. There was thus obtained 4-<strong>[7119-95-1]nitropyrazole</strong> (16 g); 1H NMR: (DMSOd6+CF3CO2H) 8.57 (s, 2H). | ||
0.97 g | With sulfuric acid; at 25℃; | 1-Nitropyrazole (1 g) was slowly added to a round-bottomed flask containing H2SO4 (98percent, 5 mL) and stirred for 20 h at room temperature. The reaction mixture was slowly transferred to a beaker containing ice with stirring. The solution was extracted with ether. The organic layer was dried with Na2SO4 then evaporated to afford 4-<strong>[7119-95-1]nitropyrazole</strong> as a colorless solid (0.97 g, 96percent). The solid was recrystallized from ether/hexane to get white crystalline compound. m.p. 163?165 °C; FT-IR (KBr, cm?1) 3186 (N?H), 1526 and 1353 cm?1 (NO2). 1H NMR (DMSO-d6) delta: 8.26 (d, 1, 5-H), 6.76 (d, 1, 3-H). EI-MS: m/z 113 (M+·). Anal. Calcd for C3H3N3O2: C, 27.54; H, 3.88; N, 32.42. Found: C, 28.31; H, 3.21; N, 31.38. |
The compound may be explosive and should be handled cautiously.Concentrated sulphuric acid (80 ml) was added dropwise to a stirred sample of <strong>[7119-95-1]<strong>[7119-95-1]1-nitropyrazol</strong>e</strong> (20.3 g) that was cooled in an ice-bath. The resultant mixture was stirred for 16 hours and allowed to warm to ambient temperature. The mixture was poured onto ice and stirred for 20 minutes. The resultant solid was isolated and washed with water. The filtrate was neutralised by the addition of potassium carbonate and extracted with diethyl ether. The recovered solid was added to the diethyl ether solution and the resultant solution was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulphate and filtered. Petroleum ether (b.p. 60-80°C) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate formed which was isolated by filtration. There was thus obtained 4-<strong>[7119-95-1]nitropyrazole</strong> (16 g); 1H NMR Spectrum: (DMSOd6 + CF3CO2H) 8.57 (s, 2H). | ||
Concentrated sulphuric acid (80 ml) was added dropwise to a stirred sample of <strong>[7119-95-1]<strong>[7119-95-1]1-nitropyrazol</strong>e</strong> (20.3 g) that was cooled in an ice-bath. The resultant mixture was stirred for <n="95"/>16 hours and allowed to warm to ambient temperature. The mixture was poured onto ice and stirred for 20 minutes. The resultant solid was isolated and washed with water. The filtrate was neutralised by the addition of potassium carbonate and extracted with diethyl ether. The recovered solid was added to the diethyl ether solution and the resultant solution was washed with a saturated aqueous sodium chloride solution, dried over magnesium sulphate and filtered. Petroleum ether (b.p. 60-80°C) was added to the filtrate which was concentrated by evaporation to a volume of about 50 ml. A precipitate formed which was isolated by filtration. There was thus obtained 4-<strong>[7119-95-1]nitropyrazole</strong> (16 g); 1H NMR Spectrum: (DMSOd6 + CF3CO2H) 8.57 (s, 2H). |
Yield | Reaction Conditions | Operation in experiment |
---|---|---|
91% | In benzonitrile; for 2h;Reflux; | A solution of 1 -nitro-1 H-pyrazole (4.23 gm, 37.4 mmol; Oakwood Products, Inc., West Columbia, SC) in benzonitrile (42 ml_) was heated to reflux for 2 hours. After cooling to 45 0C, the reaction mixture, which was starting to precipitate, was poured into 175 ml_ hexanes. A white solid precipitated. This was collected by vacuum filtration, rinsed repeatedly with hexane and dried under high vacuum to afford 3.85 grams (91 percent) of (l-27a) as a white solid; 1H NMR (400 MHz, DMSO-d6) delta 13.90 (1 H), 8.01 (1 H), 7.01 |
91% | In benzonitrile; at 180℃; for 3h; | Example 15Preparation of 3-(4-fluorophenylsulfonyl)-N-(5-methoxy-lH-pyrazol-3- vDisoq uinolin- 1-amine[00264] Step A: A stirred mixture of <strong>[7119-95-1]<strong>[7119-95-1]1-nitropyrazol</strong>e</strong> (3.45 g, 30.5 mmol) in benzonitrile (33 mL) was heated at 180 °C for 3 h. The mixture was cooled to rt, diluted with hexane and stirred at rt for 20 min. The precipitated solid was collected by filtration to afford 3-nitro-lH-pyrazole as a tan solid (3.16 g, 91percent). 1H NMR (300 MHz, DMSO-t/e) delta 13.94 (br s, 1H), 8.03 (d, J= 2.4 Hz, 1H), 7.03 (t, J= 2.4 Hz, 1H). |
91% | In benzonitrile; at 180℃; for 3h; | Step A: A stirred mixture of <strong>[7119-95-1]<strong>[7119-95-1]1-nitropyrazol</strong>e</strong> (3.45 g, 30.5 mmol) in benzonitrile (33 mL) was heated at 180° C. for 3 h. The mixture was cooled to rt, diluted with hexane and stirred at rt for 20 min. The precipitated solid was collected by filtration to afford 3-nitro-1H-pyrazole as a tan solid (3.16 g, 91percent). 1H NMR (300 MHz, DMSO-d6) delta 13.94 (br s, 1H), 8.03 (d, J=2.4 Hz, 1H), 7.03 (t, J=2.4 Hz, 1H). |
91% | With benzonitrile; at 180℃; for 3h; | A stirred mixture of <strong>[7119-95-1]<strong>[7119-95-1]1-nitropyrazol</strong>e</strong> (3.45 g, 30.5 mmol) in benzonitrile (33 mL) was heated at 180 °C for 3 h. The mixture was cooled to rt, diluted with hexane and stirred at rt for 20 min. The precipitated solid was collected by filtration to afford 3-nitro-lH-pyrazole as a tan solid (3.16 g, 91percent). H NMR (300 MHz, DMSO- 6) delta 13.94 (br s, 1H), 8.03 (d, J = 2.4 Hz, 1H), 7.03 (t, J = 2.4 Hz, 1H). |
79% | In benzonitrile; for 2h;Reflux; | Example 5 (S)-3-Cyclopentyl-N-[1-(2-methoxy-2-methyl-propyl)-1H-pyrazol-3-yl]-2-(4-methoxy-2-oxo-2,5-dihydro-pyrrol-1-yl)-propionamide A solution of <strong>[7119-95-1]1-nitro-1H-pyrazole</strong> (4.00 g, 35.4 mmol) in 40 mL of benzonitrile was refluxed for 2 h. After being cooled to 25° C., the mixture was poured into hexanes (160 mL). A white solid precipitated which was filtered and dried in vacuo, to afford 3-nitro-1H-pyrazole (3.16 g, 79percent): H1-NMR (400 MHz, DMSO-d6) delta 7.01 (1H, d, J=2.4 Hz), 8.01 (d, 1H, J=3.4 Hz). |
79% | In benzonitrile; for 2h;Reflux; | A solution of <strong>[7119-95-1]1-nitro-1H-pyrazole</strong> (4.00 g, 35.4 mmol) in benzonitrile (40 mL) was refluxed for 2 h. After being cooled to 25° C., the mixture was poured into hexanes (160 mL). A white solid precipitated which was filtered and dried in vacuo, to afford 3-nitro-1H-pyrazole (3.16 g, 79percent). 1H-NMR (400 MHz, DMSO-d6) delta 7.01 (1H, d, J=2.4 Hz), 8.01 (d, 1H, J=3.4 Hz). Intermediate 2. |
79% | In benzonitrile; for 2h;Heating / reflux; | A solution of <strong>[7119-95-1]1-nitro-1H-pyrazole</strong> (4.00 g, 35.4 mmol) in 40 mL of benzonitrile was refluxed for 2 h. After being cooled to 25° C., the mixture was poured into 160 mL of hexanes. A white solid precipitated which was filtered and dried in vacuo, to afford 3-nitro-1H-pyrazole (3.16 g, 79percent). H1-NMR (400 MHz, DMSO-d6) delta: 7.01 (1H, d, J=2.4 Hz), 8.01 (d, 1H, J=3.4 Hz). |
79% | In benzonitrile; for 2h;Heating / reflux; | Example 15 (E)-4-{3-[2-(3-Chloro-4-methanesulfonyl-phenyl)-2-cyclopentyloxyimino-acetylamino]-pyrazol-1-ylmethyl}-benzoic acid methyl ester A solution of <strong>[7119-95-1]1-nitro-1H-pyrazole</strong> (4.00 g, 35.4 mmol) in 40 mL of benzonitrile was refluxed for 2 h. After being cooled to 25° C., the mixture was poured into hexanes (160 mL). A white solid precipitated which was filtered and dried in vacuo, to afford 3-Nitro-1H-pyrazole (3.16 g, 79percent): H1-NMR (400 MHz, DMSO-d6) delta7.01 (1H, d, J=2.4 Hz), 8.01 (d, 1H, J=3.4 Hz). |
56% | at 145℃; for 10h; | N-Nitropyrazole (2 g, 18 mmol) was heated at 145 °C for 10 h in a round-bottom flask. Then the product was purified by silica column chromatography using 5:95 v/v methanol/chloroform as eluent to afford 56percent of 3(5)-<strong>[7119-95-1]nitropyrazole</strong> as a white solid. |
51% | In methoxybenzene; at 145℃; | 1-Nitropyrazole (10 g, 88 mmol) was heated in 600 ml of anisole at 145°C overnight. The mixture was cooled in a freezer which caused a precipitate to form. The precipitate was collected to give 5.075 g of the title compound as a tan solid (51percent). [M+H] calc'd for C3H3N3O2, 114; found, 114. |
In methoxybenzene; at 145℃; | 3-Nitro-lH-pyrazolew; [539] [Ref.: Janssen, J.W.A.M. and Habraken, C.L., J. Org. Chem., 1971,36,3081.] A solution of l-nitro-ll/'-pyrazole (3.0g, 0.026 mol) in anisole (200mL) was heated at 145°C overnight. The mixture was cooled to rt, the white solid was collected by filtration and washed with hexanes. The mother liquid was diluted with hexanes (500mL) and cooled to -20°C, and the resulting off-white solid was collected and combined with the previous solid.LC-MS (ES, Pos.): 1 14 [MH+]. 'H NMR (DMSO-d6, 400 MHz): 5 = 7.04 (d, J= 2.5 Hz, 1H),8.04 (d, /= 2.5 Hz, 1H), 13.96 (br s, 1H). | |
In benzonitrile; at 180℃; for 3h; | A solution of 1.0 g of <strong>[7119-95-1]N-<strong>[7119-95-1]nitropyrazole</strong></strong> in 10 mL of benzonitrile was heated for 3 h at 180 °C, after cooling the reaction mixture was poured into 30 mL of hexane. 3-<strong>[7119-95-1]nitropyrazole</strong> was collected by filtration. The crude yield after washing with hexane and drying was 0.93 g (98percent). The solid was recrystallized from water. m.p. 174?175 °C. FT-IR (KBr, cm?1) 3180 (N?H), 1520 and 1351 cm?1 (NO2). 1H NMR (DMSO-d6) delta: 7.96 (d, 1, 5(3)-H), 6.96 (d, 1, 4-H). EI-MS: m/z 113 (M+·). Anal. Calcd for C3H3N3O2: C, 31.86; H, 2.67; N, 37.16. Found: C, 32.19; H, 2.84; N, 37.18. | |
at 180℃; | A 100mL one-neck flask equipped with a magnetic stirrer was added 5g of compound 1 and 15mL acetic acid, stirred, to give a clear solution. Under ice bath 3.5mL of fuming nitric acid was slowly added dropwise to the mixed solution, maintaining vigorous stirring, the reaction temperature does not exceed 30 deg. C. 10mL acetic anhydride was added to the mixture, after the addition, the mixture immediately became cloudy, to give a white turbid liquid. After the addition it was stirred at room temperature, until the solution became clear, about 2.5h. After completion of the reaction, the solution was slowly poured into 100mL crushed ice and with vigorous stirring, potassium carbonate was added portionwise until the mixture was neutral, white precipitate was filtered to give 5.6g of white powdery crystals, the filtrate was extracted with ethyl acetate, the combined organic phase was dried over anhydrous sodium sulfate, the solvent was removed by rotary evaporation to give pale yellow crystals 1.3490g, total crude was 6.9490g, yield 91.9percent recrystallized from benzene. Weigh three 100mg compound 2 into thick-walled pressure bottle, gradually heated to 160 deg. C, 180 deg. C, 200 deg. C, the reaction at this temperature for 1 ~ 3h to obtain compound 3, the results shown in Table 1. | |
In benzonitrile; at 180℃; for 3.5h; | <strong>[7119-95-1]N-<strong>[7119-95-1]nitropyrazole</strong></strong> is dissolved in benzonitrile, heated to 180 ° C, incubated for 3.5 h,cooled to 50-60 ° C after completion of thereaction, and added to n-hexane to make 3-nitrate The pyrazole is precipitated, filtered and dried to give 3-<strong>[7119-95-1]nitropyrazole</strong>; |
Yield | Reaction Conditions | Operation in experiment |
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With potassium carbonate; In N,N-dimethyl-formamide; | Step 1c Preparation of the Nitropyrazole 4. 3-Nitropyrazole (1.13 g, 10 mmol) in dry DMF (10 ml), under argon, was treated with anhydrous K2CO3 (2.7 g, 15 mmol) and then, dropwise, with methyl-4-bromobutyrate (1.82 g, 10.05 mmol) at RT. After stirring overnight the DMF was removed and the residue partitioned between H2O and EtOAc. The combined organic extracts were washed (H2O and brine), dried (Na2SO4), filtered and evaporated to give a mixture of 4 and 6 (2.05 g) as a pale yellow oil. MS (ES+) m/z 214 (MH+). |
Yield | Reaction Conditions | Operation in experiment |
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75% | EXAMPLE 3 1-Methyl-4-nitro-3-n-propylpyrazole-5-carboxylic acid 1-Methyl-3-n-propylpyrazole-5-carboxylic acid (12.1 g, 0.072 mol) was added portionwise to a mixture of oleum (13 ml) and fuming nitric acid (11 ml), keeping the temperature below 60° C. After the addition, the mixture was heated at 60° C. overnight and then cooled to room temperature before being poured onto ice. Filtration of the precipitate gave the nitropyrazole as a white solid (11.5 g, 75percent), m.p. 124°-127° C. Found: C,45.43; H,5.22; N,19.42. C8 H11 N3 O4 requires C,45.57; H,5.20; N,19.71percent. | |
75% | PREPARATION 3 1-Methyl-4-nitro-3-n-propylpyrazole-5-carboxylic acid 1-Methyl-3-n-propylpyrazole-5-carboxylic acid (12.1 g, 0.072 mol) was added portionwise to a mixture of oleum (13 ml) and fuming nitric acid (11 ml), keeping the temperature below 60° C. After the addition, the mixture was heated at 60° C. overnight and then cooled to room temperature before being poured onto ice; filtration then gave the nitropyrazole as a white solid (11.5 g, 75percent), m.p. 124°-127° C. Found: C,45.43; H,5.22; N,19.42. C8 H11 N3 O4 requires C,45.57; H,5.20; N,19.71percent | |
75% | EXAMPLE 97 1-Methyl-4-nitro-3-n-propylpyrazole-5-carboxylic acid 1-Methyl-3-n-propylpyrazole-5-carboxylic acid (12.1 g, 0.072 mol) was added portionwise to a mixture of oleum (13 ml) and fuming nitric acid (11 ml), keeping the temperature below 60° C. After the addition, the mixture was heated at 60° C. overnight and then cooled to room temperature before being poured onto ice. Filtration of the precipitate gave the nitropyrazole as a white solid (11.5 g, 75percent), m.p. 124-127° C. Found: C,45.43; H,5.22; N,19.42. C8H11N3O4 requires C,45.57; H,5.20; N,19.71percent. |
75% | PREPARATION 13 1-Methyl-4-nitro-3-n-propylpyrazole-5-carboxylic acid 1-Methyl-3-n-propylpyrazole-5-carboxylic acid (12.1 g, 0.072 mol) was added portionwise to a mixture of oleum (13 ml) and fuming nitric acid (11 ml), keeping the temperature below 60° C. After the addition, the mixture was heated at 60° C. overnight and then cooled to room temperature before being poured onto ice; filtration then gave the nitropyrazole as a white solid (11.5 g, 75percent), m.p. 124-127° C. Found: C,45.43; N,5.22; N,19.42. C8H11N3O4 requires C,45.57; H,5.20; N,19.71percent. |