18 - Amines And Their Reactions Flashcards
What can happen when you form an amine such as propylamine?
Ammonia has a lone pair of electrons which attack the carbon-halogen bond. The product, from the amine production, propylamine, also has a lone pair of electrons. Tree reform or can attack another molecule of 1-chloropropsne. For example: CH3CH2CH2NH2 + CH3CH2CH2Cl -> (CH3CH2CH2)2NH2 + HCl.
How do you prepare a primary aliphatic amine?
Halogenoalkane + excess Ammonia (+ ethanol solvent) -> primary aliphatic amine. An example: CH3CH2CH2Cl + NH3 -> CH3CH2CH2NH2 + HCl. Further ammonia ma then react with the HCl. NH3 + HCl -> NH4+Cl-.
How can nitrobenzene be reduced? What reaction is this? What symbol is used?
This is a reduction reacts. It’s reduced using a mixture of tin and HCl, under reflux, followed by the neutralisation of excess HCl. Tis forms an aromatic amine. The reducing agent is shown in the east ion as [H].
What are the two steps in the production of dyestuffs?
The two steps in the production of dyestuffs are diazotisation and coupling.
What happens in diazotisation?
A diazonium ion is formed. A mixture of nitrous acid and phenylamine kept below 10 C forms a diazonium salt. The nitrous acid involved in the reaction is generated in situ. Nitrous acid is formed by reacting tougher NaNO2 and excess HCl. NaNO2 + HCl -> HNO2 + NaCl. The cold nitrous acid reacts with aromatic amine to form a diazonium salt.
What happens in coupling?
The diazonium salt generated in diazotisation reacts with Phenol (or another aromatic compound such as an amine) under alkaline conditions. This results in the benzene rings joining together through an azo functional group, -N=N-.
