1,1-diphenylethanol is an alcohol compound. Two benzene groups are attatched to the same carbon which has -OH group also. 1,1-diphenylethanol is a benzene substituted alcohol compound.
In this tutorial, we learn followings with preparing of 1,1-diphenylethanol.
Like aliphatic ethanols, we can prepare aromatic alcohols. Here we try to make benzene substituted alcohol compound using grignard reagent. In this example IUPAC name is given, then you have to draw the structure of molecule. We can understand this compound is an alcohol because IUPAC name ends with ol part. Two benzene molecules are bonded to a same carbon atom as substitutes (1,1-diphenyl). The root chain has two carbon atoms (eth). Also 1,1-diphenylethanol can be named as 1-Diphenyle-ethane-1-ol.
According to the IUPAC nomenclature, two phenyl groups are connected to the number one carbon atom of main chain. In the main chian, there are two carbon atoms with alcohol group. The carbon atom which hold the -OH group, taked the number one.
You can start your conversion from benzene and ethanol. Each step of benzene to 1,1-diphenylethanol is explained below.
Chlorobenzene is prepared by the reaction of benzene and chlorine gas ( Cl2 ) in the presence of AlCl3.
Next, chlorobenzene reacts with magnesium with dry ether and give grignard reagent (phenyl magnesium chloride) .
Ethanol is oxidized to ethanoic acid by strong oxidizing agent such as acidic potassium permanganate ( H+ / KMnO4 ). When oxidizing reaction is occurred purple colour of acidic potassium permanganate is reduced or become colourless because MnO4- is reduced to Mn2+.
When carboxylic acid chloride compound is treated with excess grignard reagent, two alkyl groups (in the grignard reagent) are added to the carboxylic acid chloride and forms tertiary alcohol when water is added.
Finally grignard reagent and ethanoyl chloride are mixed together and add water. Two phenyl groups are added to the ethanoyl chloride molecule. It gives 1-diphenylethanol which is a tertiary alcohol.
1,1-diphenylethanol is an tertiary alcohol. Acidity of 1,1-diphenylethanol is less than ethanol.