amines Flashcards
what are amines
compounds based on ammonia where one or more of the hydrogen atoms have been replaced by alkyl or aryl groups
what can amines be classified as
primary secondary or tertiary
Preparation of aromatic amines from nitrobenzenes: reagents and conditions
Conc hcl and tin catalyst
Preparation of aromatic amines from nitrobenzenes: equation
Benzene-NO2 + 6[H] > benzene-NH2 + 2H2O
Preparation of aromatic amines from nitrobenzenes: reaction type
Reduction
Preparation of aromatic amines from nitrobenzenes: uses of aromatic amines
Dyes and drugs
General formula aliphatic amines
CnH2n+3N
Preparation of primary aliphatic amines from halogenoalkanes: reagents and conditions
Excess ammonia in ethanol and warm
Preparation of primary aliphatic amines from halogenoalkanes: general equation
RBr + 2NH3 > RNH2 + NH4+Br-
Preparation of primary aliphatic amines from halogenoalkanes: mechanism
Nucleophilic substitution
Preparation of primary aliphatic amines from halogenoalkanes: why must excess ammonia be used
To prevent further substitution
Preparation of primary aliphatic amines from nitriles: reagents and conditions
H2 Ni catalyst
Preparation of primary aliphatic amines from nitriles: general equation
R-C(triple bond)N + 2H2 > RCH2NH2
Base
Substance that accepts H+ ions
Why are ammonia and amines weak bases
Lone pair of electrons on the nitrogen atom, which can accept a proton from an acid
What do amines dissolve in acids to give
The corresponding alkyl-ammonium salt
How can the amine be reformed from an alkylammonium salt
By adding an alkali
What is the ability of a substance to act as a base termed
Basicity
What is the order of basicity of amines
Primary amines>NH3>benzene NH2
Comparing primary aliphatic amines and ammonia: what does the alkyl group in primary amines release and why
Electron density towards the nitrogen atom due to positive inductive effect
Comparing primary aliphatic amines and ammonia: what does release of electron density towards nitrogen atom increase
Electron density on the nitrogen atom and the lone pair is more available to accept H+
Comparing primary aliphatic amines and ammonia: are aliphatic amines stronger bases than ammonia
Yes
Comparing primary aromatic amines and ammonia: where is the lone pair of electrons on the nitrogen atom of aromatic amines
Delocalised into the pi ring
Comparing primary aromatic amines and ammonia: what effect does the delocalisation of the lone pair have on the electron density of the nitrogen atom
Decreases it- lone pair less available to accept H+
Comparing primary aromatic amines and ammonia: are aromatic amines weaker bases than ammonia
Yes
What does relative basicity depend on
The availability of the lone pair on the N atom
The more available the lone pair is, the ? The base
Stronger
Why are amines nucleopgiles
Nitrogen atom of amines able to donate a lone pair of electrons
Nucleopgile
Electron pair donor
Reaction of ammonia with halogenoalkanes: general equation
R-Hal + 2NlpH3 > RNlpH2+ NH4+Hal-
Reaction of ammonia with halogenoalkanes: mechanism
Nuc substitution
Reaction of primary amines with halogenoalkanes: general equation
RHal + 2R1NlpH2 > RR1NH + R1NH3+Hal-
Reaction of secondary amines with halogenoalkanes: general equation
RHal + 2R1(sq)NH > RR1(sq)N + R1(sq)NH2+Hal-
Reaction of tertiary amines with halogenoalkanes: general equation
R-Hal + R1(cub)N > RR1(cub)N+Hal-
What are quaternary ammonium salts used as
Cationic surfactants in household products such as detergent and fabric softeners
What are surfactants
Compounds with regions which are partly soluble in water and partly insoluble
What charge do quaternary ammonium salts have
Positive- cationic
Which region of the quaternary ammonium salt is ionic
The N+
Soluble in water
Which part of the quaternary ammonium salt is not water soluble
The long non polar hydrocarbon region
Nucleophilic addition elimination reactions of ammonia with acyl chlorides: general equation
RCOCl + NH3 > RCONH2 + H+ + Cl-
Nucleophilic addition elimination reactions of ammonia with acyl chlorides: organic product
Amide
Nucleophilic addition elimination reactions of ammonia with acyl chlorides: mechanism
Nuc addition elimination
Nucleophilic addition elimination reactions of amines with acyl chlorides: general equation
RCOCl + R1NH2 > RCONHR1 + H+Cl-
Nucleophilic addition elimination reactions of amines with acyl chlorides: organic product
N substituted amide
Nucleophilic addition elimination reactions of ammonia with acid anhydrides: general equation
RCOOCOR + NH3 > RCONH2 + RCOOH
Nucleophilic addition elimination reactions of ammonia with acid anhydrides: organic product
Amide and carboxylic acid
Nucleophilic addition elimination reactions of amines with acid anhydrides:
RCOOCOR + R1NH2 > RCONR1H + RCOOH
Nucleophilic addition elimination reactions of amines with acid anhydrides: organic product
N substituted amide
equation for ethyl amine and acid (HCl)
CH3CH2NH2 + HCl > CH3CH2N+H3Cl-
equation for alkylammonium salt and alkali
CH3CH2NH3 + OH- > CH3CH2NH2 + H2O