METHOD FOR PREPARING ESTERIFIED ALKANE

Abstract

The present disclosure relates to a method for preparing an esterified alkane. The method includes mixing a gaseous alkane with oxygen or air to obtain a mixed gas; adding a chlorine-containing catalyst and/or a nitrogen-containing catalyst to a light-transmission reaction vessel; then adding the mixed gas, an acid and a solvent in sequence to carry out a reaction under ambient pressure and an illumination condition; and then conducting analysis to obtain an NMR yield, followed by extraction, drying, filtration, distillation under reduced pressure and separation by column chromatography to obtain an esterified alkane. The present disclosure has the advantages that the reaction can be carried out under the conditions of ambient temperature and pressure with a cheap and safe chlorine-containing compound and a nitrogen-containing compound as a catalyst and air as an oxidant, and the method has energy-saving and economic effects, convenient and safe operation and environmental friendliness.

Claims

1. A method for preparing an esterified alkane, comprising mixing a gaseous alkane with oxygen or air to obtain a mixed gas; adding a chlorine-containing catalyst and/or a nitrogen-containing catalyst to a light-transmission reaction vessel; adding the mixed gas, an acid and a solvent in sequence to carry out a reaction under normal pressure and an illumination condition; and conducting analysis to obtain a nuclear magnetic yield, followed by extraction, drying, filtration, distillation under reduced pressure and separation by column chromatography to obtain an esterified alkane.

2. The method for preparing an esterified alkane according to claim 1, wherein the gaseous alkane is methane.

3. The method for preparing an esterified alkane according to claim 2, wherein a volume ratio of the gaseous alkane to oxygen or air is (2-6):1.

4. The method for preparing an esterified alkane according to claim 1, wherein the chlorine-containing catalyst is a chlorinated metal salt or hydrogen chloride.

5. The method for preparing an esterified alkane according to claim 1, wherein the nitrogen-containing catalyst comprises nitric acid, nitrous acid, nitrate, nitrite and a nitrogen oxide.

6. The method for preparing an esterified alkane according to claim 1, wherein the acid is a protonic acid.

7. The method for preparing an esterified alkane according to claim 1, wherein a molar amount of the chlorine-containing catalyst is 10% to 500% of that of the alkane; a molar amount of the nitrogen-containing compound is 0.01% to 100% of that of the alkane; and a molar amount of the acid is 100% to 500% of that of the chlorine-containing catalyst and/or the nitrogen-containing catalyst.

8. The method for preparing an esterified alkane according to claim 1, wherein the solvent is an acidic solvent or a neutral solvent, the acidic solvent is an organic acid, and the neutral solvent is CH.sub.3NO.sub.2, CH.sub.2Cl.sub.2 or CHCl.sub.3.

9. The method for preparing an esterified alkane according to claim 1, wherein the illumination condition comprises natural light or an external light source, and the external light source is an incandescent lamp, a linear fluorescent lamp, a compact fluorescent lamp, an LED lamp or an ultraviolet lamp with a power of greater than 4 W.

10. The method for preparing an esterified alkane according to claim 1, wherein the reaction is controlled at a temperature of −5° C. to 110° C. for 2-168 hours.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present disclosure is described in detail with reference to the particular examples below. The following particular examples will be conducive to further understanding by those skilled in the art on the present disclosure, but are not intended to limit the present disclosure in any forms. It should be pointed out that various transformations and modifications can be made by those of ordinary skill in the art without departing from the spirit of the present disclosure, and all the transformations and modifications fall within the scope of protection of the present disclosure.

Example 1

[0031] ##STR00005##

[0032] Methane was premixed with oxygen at a ratio of 2:1 to obtain a mixed gas. Sodium nitrite (0.0023 mmol) was added into a Schlenk tube, vacuumization was conducted for gas exchange, 35 mL of the mixed gas, 37% hydrochloric acid (1.91 mmol) and trifluoroacetic acid (0.7 mL) were added in sequence, then a screw opening was screwed, and stirring was conducted under illumination of a 23-watt LED white lamp 1 cm away from the reactor. After a reaction was completed, 10 mL of CDCl.sub.3 was added and fully shaken, a quantitative internal standard (nitromethane) was added and stirred for 30 seconds, and 0.5 g of anhydrous sodium sulfate was added for precipitation for 10 minutes. Then, about 500 μL of a supernatant was taken and detected by .sup.1H NMR, and the yield was calculated.

[0033] This example illustrates a reaction at normal temperature, with the trifluoroacetic acid as a solvent, the methane and the oxygen as substrates/reactants, the nitrite as a catalyst whose dosage was 0.2% of that of the methane, and the hydrochloric acid as an acid under illumination of the 23-watt LED energy-saving lamp as a light source.

Example 2

[0034] ##STR00006##

[0035] Methane was premixed with air at a ratio of 1:2.4 (where the ratio of the methane to oxygen was 2:1) to obtain a mixed gas. Sodium nitrite (0.0010 mmol) was added into a Schlenk tube, vacuumization was conducted for gas exchange, 35 mL of the mixed gas, 37% hydrochloric acid (0.85 mmol) and trifluoroacetic acid (0.3 mL) were added in sequence, then a screw opening was screwed, and stirring was conducted under illumination of a 23-watt LED white lamp 1 cm away from the reactor. After a reaction was completed, 10 mL of CDCl.sub.3 was added and fully shaken, a quantitative internal standard (nitromethane) was added and stirred for 30 seconds, and g of anhydrous sodium sulfate was added for precipitation for 10 minutes. Then, about 500 μL of a supernatant was taken and detected by .sup.1H NMR, and the yield was calculated.

[0036] This example illustrates a reaction with the methane and the air as reactants.

Example 3

[0037] ##STR00007##

[0038] Methane was premixed with oxygen at a ratio of 2:1 to obtain a mixed gas. Sodium nitrite (0.0023 mmol) was added into a Schlenk tube, vacuumization was conducted for gas exchange, mL of the mixed gas, 37% hydrochloric acid (1.91 mmol) and trifluoroacetic acid (0.7 mL) were added in sequence, then a screw opening was screwed, stirring was conducted under illumination of a 23-watt LED white lamp 1 cm away from the reactor, and air-blowing was conducted with a heater 20 cm away from the reactor. After a reaction was completed, cooling was conducted to normal temperature, 10 mL of CDCl.sub.3 was added and fully shaken, a quantitative internal standard (nitromethane) was added and stirred for 30 seconds, and 0.5 g of anhydrous sodium sulfate was added for precipitation for 10 minutes. Then, about 500 μL of a supernatant was taken and detected by .sup.1H NMR, and the yield was calculated.

[0039] This example illustrates a reaction at a heating temperature of 110° C.

Example 4

[0040] ##STR00008##

[0041] Methane was premixed with oxygen at a ratio of 2:1 to obtain a mixed gas. Sodium chloride (0.95 mmol) and sodium nitrite (0.0023 mmol) were added into a Schlenk tube in sequence, vacuumization was conducted for gas exchange, 35 mL of the mixed gas, 10 M sulfuric acid (1.91 mmol) and trifluoroacetic acid (0.7 mL) were added in sequence, then a screw opening was screwed, and stirring was conducted under illumination of a 23-watt LED white lamp 1 cm away from the reactor. After a reaction was completed, 10 mL of CDCl.sub.3 was added and fully shaken, a quantitative internal standard (nitromethane) was added and stirred for 30 seconds, and 0.5 g of anhydrous sodium sulfate was added for precipitation for 10 minutes. Then, about 500 μL of a supernatant was taken and detected by .sup.1H NMR, and the yield was calculated.

[0042] This example illustrates a reaction when the chlorine-containing compound is sodium chloride and the acid is sulfuric acid.

Example 5

[0043] ##STR00009##

[0044] Methane was premixed with oxygen at a ratio of 2:1 to obtain a mixed gas. Sodium chloride (0.95 mmol) and sodium nitrite (0.0023 mmol) were added into a Schlenk tube in sequence, vacuumization was conducted for gas exchange, 35 mL of the mixed gas and trifluoroacetic acid (0.7 mL) were added in sequence, then a screw opening was screwed, and stirring was conducted under illumination of a 23-watt LED white lamp 1 cm away from the reactor. After a reaction was completed, 10 mL of CDCl.sub.3 was added and fully shaken, a quantitative internal standard (nitromethane) was added and stirred for 30 seconds, and 0.5 g of anhydrous sodium sulfate was added for precipitation for 10 minutes. Then, about 500 μL of a supernatant was taken and detected by .sup.1H NMR, and the yield was calculated.

[0045] This example illustrates a reaction when the chlorine-containing compound is sodium chloride, the acid is trifluoroacetic acid and no solvent is used, or a reaction when the chlorine-containing compound is sodium chloride, the solvent is trifluoroacetic acid and no additional acid is used.

Example 6

[0046] ##STR00010##

[0047] Methane was premixed with oxygen at a ratio of 2:1 to obtain a mixed gas. Sodium nitrate (0.0023 mmol) was added into a Schlenk tube, vacuumization was conducted for gas exchange, 35 mL of the mixed gas, 37% hydrochloric acid (1.91 mmol) and trifluoroacetic acid (0.7 mL) were added in sequence, then a screw opening was screwed, and stirring was conducted under illumination of a 23-watt LED white lamp 1 cm away from the reactor. After a reaction was completed, 10 mL of CDCl.sub.3 was added and fully shaken, a quantitative internal standard (nitromethane) was added and stirred for 30 seconds, and 0.5 g of anhydrous sodium sulfate was added for precipitation for 10 minutes. Then, about 500 μL of a supernatant was taken and detected by .sup.1H NMR, and the yield was calculated.

[0048] This example illustrates a reaction when the nitrogen-containing compound is nitrate.

Example 7

[0049] ##STR00011##

[0050] Methane was premixed with oxygen at a ratio of 2:1 to obtain a mixed gas. Vacuumization was conducted on a Schlenk tube for gas exchange, 35 mL of the mixed gas and a preprepared nitrogen oxide gas (0.0045 mmol), 37% hydrochloric acid (1.91 mmol) and trifluoroacetic acid (0.7 mL) were added in sequence, then a screw opening was screwed, and stirring was conducted under illumination of a 23-watt LED white lamp 1 cm away from the reactor. After a reaction was completed, 10 mL of CDCl.sub.3 was added and fully shaken, a quantitative internal standard (nitromethane) was added and stirred for 30 seconds, and 0.5 g of anhydrous sodium sulfate was added for precipitation for 10 minutes. Then, about 500 μL of a supernatant was taken and detected by .sup.1H NMR, and the yield was calculated.

[0051] This example illustrates a reaction when the nitrogen-containing compound is a nitrogen oxide.

Example 8

[0052] ##STR00012##

[0053] Methane was premixed with oxygen at a ratio of 2:1 to obtain a mixed gas. Sodium nitrite (0.0023 mmol) was added into a Schlenk tube, vacuumization was conducted for gas exchange, 35 mL of the mixed gas, 37% hydrochloric acid (1.91 mmol) and trifluoroacetic acid (0.7 mL) were added in sequence, then a screw opening was screwed, and stirring was conducted under illumination of a 10-watt 365-375 nm LED ultraviolet lamp 1 cm away from the reactor. After a reaction was completed, 10 mL of CDCl.sub.3 was added and fully shaken, a quantitative internal standard (nitromethane) was added and stirred for 30 seconds, and 0.5 g of anhydrous sodium sulfate was added for precipitation for 10 minutes. Then, about 500 μL of a supernatant was taken and detected by .sup.1H NMR, and the yield was calculated.

[0054] This example illustrates a reaction under illumination of the 10-watt LED ultraviolet lamp as a light source.

Example 9

[0055] ##STR00013##

[0056] Methane was premixed with oxygen at a ratio of 2:1 to obtain a mixed gas. Sodium nitrite (0.0045 mmol) was added into a quartz sheet, vacuumization was conducted for gas exchange, 50 mL of the mixed gas, 37% hydrochloric acid (4.40 mmol) and trifluoroacetic acid (1.6 mL) were added in sequence, then a valve was turned off, and stirring was conducted under illumination of a 23-watt LED white lamp 1 cm away from the reactor. 24 hours later, 10 mL of the mixed gas was supplemented. 24 hours later, 10 mL of the mixed gas was supplemented. 24 hours later, 10 mL of the mixed gas was supplemented. After a reaction was completed, 10 mL of CDCl.sub.3 was added and fully shaken, a quantitative internal standard (nitromethane) was added and stirred for 30 seconds, and 0.5 g of anhydrous sodium sulfate was added for precipitation for 10 minutes. Then, about 500 μL of a supernatant was taken and detected by .sup.1H NMR, and the yield was calculated.

[0057] This example illustrates a reaction when a material is continuously supplemented.

Example 10

[0058] ##STR00014##

[0059] Methane was premixed with oxygen at a ratio of 6:1 to obtain a mixed gas. Sodium nitrite (0.0045 mmol) was added into a quartz sheet, vacuumization was conducted for gas exchange, 50 mL of the mixed gas, 37% hydrochloric acid (4.40 mmol) and trifluoroacetic acid (1.6 mL) were added in sequence, then a valve was turned off, and stirring was conducted under illumination of a 23-watt LED white lamp 1 cm away from the reactor. 24 hours later, 10 mL of the mixed gas was supplemented. 24 hours later, 10 mL of the mixed gas was supplemented. 24 hours later, 10 mL of a mixed gas of methane and oxygen at a ratio of 2:1 was supplemented. After a reaction was completed, 10 mL of CDCl.sub.3 was added and fully shaken, a quantitative internal standard (nitromethane) was added and stirred for 30 seconds, and 0.5 g of anhydrous sodium sulfate was added for precipitation for 10 minutes. Then, about 500 μL of a supernatant was taken and detected by .sup.1H NMR, and the yield was calculated.

[0060] This example illustrates a reaction when the methane and the oxygen are used as initial raw materials at a ratio of 6:1 and then supplemented continuously.

Example 11

[0061] ##STR00015##

[0062] Methane was premixed with oxygen at a ratio of 2:1 to obtain a mixed gas. Sodium nitrite (0.0023 mmol) was added into a quartz sheet, vacuumization was conducted for gas exchange, 35 mL of the mixed gas, 37% hydrochloric acid (1.91 mmol) and trifluoroacetic acid (0.7 mL) were added in sequence, then a valve was turned off, and stirring was conducted under illumination of a 23-watt LED white lamp 1 cm away from the reactor. 24 hours later, 7 mL of the mixed gas and the 37% hydrochloric acid (1.91 mmol) were supplemented for six times repeatedly. After a reaction was completed, 10 mL of CDCl.sub.3 was added and fully shaken, a quantitative internal standard (nitromethane) was added and stirred for 30 seconds, and 0.5 g of anhydrous sodium sulfate was added for precipitation for 10 minutes. Then, about 500 μL of a supernatant was taken and detected by .sup.1H NMR, and the yield was calculated.

[0063] This example illustrates a reaction when materials are continuously supplemented for a long time.