1-Phenylethanol can be prepared by reaction of benzaldehyde witha)Meth...
Preparation of 1-Phenylethanol using benzaldehyde and methyl iodide with magnesium as a reagent is discussed below.
Explanation:
- The reaction is an example of Grignard reaction, where the organometallic compound is formed by the reaction of an organic halide with magnesium metal.
- In this case, benzaldehyde and methyl iodide are the reactants, and magnesium is the reagent.
- The reaction proceeds as follows:
- First, magnesium reacts with methyl iodide to form magnesium iodide and methyl magnesium iodide.
Mg + CH3I → MgI + CH3MgI
- Next, the methyl magnesium iodide reacts with benzaldehyde to form 1-phenyl-1-propanol, also known as 1-phenylethanol, and magnesium bromide.
CH3MgI + C6H5CHO → C6H5CH(OH)CH3 + MgBrI
- The product, 1-phenylethanol, is a clear, colorless liquid with a sweet floral odor. It is used in the perfume and flavor industries.
- The reaction is carried out in anhydrous conditions, and the reaction mixture is usually cooled to prevent excessive reaction or unwanted side reactions.
- The yield of the product can be improved by using excess benzaldehyde or by adding water or dilute acid to the reaction mixture to hydrolyze any remaining Grignard reagent.
Therefore, the correct option is D, methyl iodide and magnesium, for the preparation of 1-phenylethanol from benzaldehyde.