Acetic anhydride may be prepared at home in a simple manner with the use of bromine and sulfur.
This method avoids the corrosive and highly toxic, although it is present and one such substance - bromo.
Due to the fact that the acetic anhydrideused for the production of drugs and explosives, to get it in a store of chemicals is not possible. As well as this is not possible, so it is difficult to get it at home. All industrial methods can not be applied at home. Therefore, there is needed a special way. Choose the method of using bromine.
The main reaction is:
8SN3SOONa + S + 3Br2 = 4 (CH3CO) 2O + Na2SO4 + 6NaBr
Equipment and Reagents
- Liebig condenser (used to thin sections)
- Sand Bath
- Bulb cone, heat-resistant, with thin sections
- pull out drobe
- Glass rod
- Flask with ground glass stopper
- Pan for calcination
- Technical scale
- Disposable syringe of 20 cm3
- Sulfur, 999
- Sodium acetate anhydrous
Before using laboratory glassware to heatto remove moisture. Even the slightest presence of unacceptable amounts of water, as a result of acetic anhydride enters it reacted to form acetic acid.
Sulphur and sodium acetate
In technical balance weigh 3.3 g of sulfur and placed in a flask stoppered with a lid. Set aside.
Sodium acetate should be calcined to melt,since it is hygroscopic. On the technical balance weigh 66.5 grams of salt, making the supply of 1-1.5 g, ie 67,5-68 total of placing it in the pan and ignited to melt. Fire make middle to avoid charring substances. Once the salt is dealt, pour it in a mortar and grind to a powder. We need to have time to do it until it solidifies. Ignited it in the pan to melt. Warming is not much else can char. Once it is completely melted, pour into a mortar and after the hardening, crushed into powder. Pour the powder into the reaction flask.
A solution of bromine in sulfur
Since bromine - a toxic substance, to prepare a solution of a hood is recommended. It can be made with your own hands.
Before preparing a solution of bromine to put on a few minutes in the freezer. Dial 15.5 cm3 of cooled bromine and pour into the flask with sulfur close stoppered. Chat flask to dissolve sulfur.
Preparation of acetic anhydride
The container with ice to put flask acetatesodium, insert a glass rod into it and slowly tide solution of sulfur in bromine. Must be stirred continuously. The solution may be warmed up. Strong heating unacceptable! After the bromine solution in sulfur flow to a solution of sodium acetate must be left in the container bottom flask with ice for a while. The process may appear bromine vapors. Do not pay attention to it. After 10 minutes, the mixture becomes pale cream color. Continue stirring for 30 minutes.
Acetic anhydride was distilled off
After this period of time appearvinegary smell. It is possible to start the distillation process. To do this, prepared a sand bath heated to 155-160 degrees Celsius, parallel mounting the installation: a refrigerator is connected to the flask using a nozzle wurtzite. anhydride boiling temperature is almost 140 degrees Celsius. It is important not to overheat! Temperature control is performed by using external thermocouple with digital tester. The stripped anhydride can once again surpass, adding a little sodium acetate.