Ethane-1,2-diol is a diol which contains two carbon atoms and two hydroxyl groups. Both hydroxyl groups are attached to adjacent carbon atoms. In this tutorial, we are focusing to prepare ethane-1,2-diol from ethanol.
We will discuss two methods to convert ethanol to ethane-1,2-diol. Follow safety sheets to protect you and others. Hazards of chemicals used in this conversion are discussed later in this tutorial.
In this tutorial, we are going to look at two methods of preparing ethane-1,2-diol.
In both methods, first, we have to convert ethanol to ethene. For that, ethanol is heated with a dehydrator such as concentrated sulfuric acid or alumina. It will give ethene as the product.
When ethene reacts with basic potassium permanganate, ethane-1,2-diol is given. Basic potassium permanganate is prepared by dissolving little bit of anhydrous sodium carbonate in potassium permanganate solution. in this reaction, ethene is oxidized to ethane-1,2-diol.
CH2=CH2 + KMnO4 / OH- → HO-CH2-CH2-OH
Otherwise, we have an alternative way to prepare ethane-1,2-diol if we don't have basic potassium permanganate in the laboratory.
At that case, liquid bromine in CCl4 medium is added to ethene to produce 1,2-dibromoethane. Then, 1,2-dibromoethane reacts with dilute NaOH to get ethane-1,2-diol by replacing both bromine atoms.
Br-CH2-CH2Br + NaOH → HO-CH2-CH2-OH
Ethylene glycol is a toxic chemical. If it is injested into your body, it can damage your nervous system, heart and kidneys. If sufficient amount is ingested, it can be fatal.
Ethene is prepared in both methods we discussed in preparation of ethylene glycol. Exposure to Ethylene can cause headache, dizziness, fatigue, lightheadedness, confusion and unconsciousness. Ethylene is a highly combustible gas. Therefore, don't work with naked flames when ethene is prepared.
This is a single step reaction. Reaction between, ethene and Baeyer's reagent will give ethane-1,2-diol as the product. Baeyer’s reagent is an alkaline solution of cold potassium permanganate. Baeyer’s reagent is prepared by dissolving anhydride sodium carbonate in potassium permanganate solution. Solution should be cold.
When, ethene reacts with Baeyer’s reagent, it gives ethane,1-2-diol and brown colour manganese dioxide.
Questions
Ethane-1,2-diol has two acidic -OH groups which can react with more sodium metal than ethanol does.
ethane-1,2-diol can be used to prepare acetylene gas which is used welding purposes. ethane-1,2-diol is heated with concentrated sulfuric acid to prepare acetylene.
Yes.
Ethane is an alkane compound which are very less reactive. It is not simple to prepare ethane-1,2-diol from ethane.