Question

Carboxylic acids can be made by the hydrolysis of nitriles, which in turn can be made from an alkyl halide. Draw the structures of a starting alkyl bromide and the intermediate nitrile that would be used in the synthesis of 3-methylbutanoic acid (isovaleric acid) Do not show free ions.

alkyl bromide   nitrile isovaleric

                                                                                       acid

Answer 1

Concepts and reason

A chemical reaction involving the synthesis of a carboxylic acid (isovaleric acid) from a haloalkane (alkyl bromide) is given. The reagents are given and the structure of the starting alkyl bromide and the intermediate alkyl nitrile needs to be given.

A chemical reaction involves the reaction between two or more substances. The reaction process is helped by the reagents that help in bringing about the transformation of the reactant into product.

Fundamentals

The alkyl halides undergo substitution reaction when treated with cyanide ion as follows. The alkyl cyanide further undergoes hydrolysis to give carboxylic acid as shown below:

Thus, the addition of cyanide ion is a step-up reaction that is it increases the number of carbons in the carbon chain by one.

The structure of isovaleric acid is as follows:

The structure of the alkyl bromide is as follows:

The reaction is as follows:

Ans: