Question

Tyramine is an alkaloid found in mistletoe and ripe cheese. Dopamine is a neurotransmitter involved in the regulation of the central nervous system.

Tyramine Dopamine

a. How can tyramine be prepared from \({\bf{\beta }}\)-phenylethylamine?

b. How can dopamine be prepared from tyramine?

c. Give two ways to prepare \({\bf{\beta }}\) -phenylethylamine from \({\bf{\beta }}\)-phenylethyl chloride.

d. How can \({\bf{\beta }}\)-phenylethylamine be prepared from benzyl chloride?

e. How can \({\bf{\beta }}\)- phenylethylamine be prepared from benzaldehyde?

Short answer

a.

Reaction

b.

Reaction

c.

Reaction

d.

Reaction

e.

Reaction

Step-by-step solution

Tyramine and Dopamine

Tyramine is a compound containing a hydroxyl group and ethylamine cation substituted on a benzene ring. Dopamine is a compound containing two hydroxyl groups and ethylamine cation substituted on a benzene ring.

Subpart (a)

The reaction for the synthesis of tyramine from \({\bf{\beta }}\)-phenylethylamine is given below.

Reaction

Subpart (b)

The reaction for the synthesis of dopamine from tyramine is given below.

Reaction

Subpart (c)

The reaction for the preparation of \({\bf{\beta }}\)-phenylethylamine from \({\bf{\beta }}\)-phenylethyl chloride is given below.

Reaction

Subpart (d)

The reaction for the preparation of \({\bf{\beta }}\)-phenylethylamine from benzyl chloride is given below.

Reaction

Subpart (e)

The reaction for the preparation of \({\bf{\beta }}\)-phenylethylamine from benzaldehyde is given below.

Reaction