synthetic routes Flashcards
what are the conditions for combustion?
heat and oxygen
What does radical substitution require?
UV light
what are the 3 steps for homolytic free-radical substitution
initiation- making free radicals
propagation- regeneration of free radicals
termination- two FRs join together to make a stable compound
why is the yield of homolytic free-radical substitution low?
multiple substitution/ substitution at different points on the carbon chain
what is required for hydrogenation?
high temperature and nickel catalyst
what can turn an alkene into an alkane?
hydrogenation
what is the test for unsaturation
bromine water decolourises
aklene + ? = haloalkane
halogen eg Br2/Cl2
what is required to turn an alkene to an alcohol
steam/ phosphoric acid
what is the name of the reaction which turns an alkene into an alcohol
hydration
what mechanism occurs when a hydrogen halide is added to an alkene
electrophilic addition
what is Markownikoff’s rule
hydrogen adds to the carbon with most hydrogens already attached
what are the conditions for addition polymerisation
Ni catalyst/ high temp and pressure
what is required for the dehydration of alcohols
reflux and concentrated acid
what are the products of the dehydration of an alcohol
alkene and water
what is the oxidising agent for alcohols
acidified potassium dichromate
primary alcohol + [O] —->
ketone (distillation)
carboxylic acid (reflux)
secondary alcohol —> ketone requires what reagents and conditions?
acidified potassium dichromate and reflux
what is the name of the mechanism that turns a haloalkane into an alcohol?
nucleophilic substitution
nucleophilic substitution (X-Cl bond takes longest as strongest BE)
what are the conditions for hydrolysis of haloalkanes
reflux and NaOH
what is the mechanism that breaks down the ozone layer
free radical substitution
what reaction allows the halogenation/ alkylation/ acylation of benzene?
Friedal Crafts
what is required for the halogenation of benzene
a halogen carrier such as AlBr3 or FeBr3 and room temperature and pressure
what are the steps of a friedal crafts mechanism?
halogen carried
mechanism
catalyst regenerated
what is required for the nitration of benzene
concentrated sulfuric acid calalyst and nitric acid.
what is the electrophile in the nitration of benzene
NO2+
phenol + base (eg NaOH) —–>
salt + water
what is required for the halogenation of phenol
room temperature and excess Bromine
phenol + 3Br2——>
phenol with Br substituted in the 2,4,6 position + 3HBr
(white ppt and bromine water decolourised)
what is required for the nitration of phenol
dilute nitric acid and room temp (no halogen carrier)
what is needed for the bromination of nitribenzene compared to phenylamine
for phenylamine, reaction is fast as the amine group activates the ring, rtp
nitrobenzene is fairly unreactive so requires a halogen carrier
what is the reagent for the reduction of aldehydes and ketones
sodium borohydride
what is the name of the mechanism for the reduction of aldehydes and ketones
nucleophilic addition
the nucleophile is the hydride ion
aldehyde —–>
( distill and NaBH4)
primary alcohol
ketone —–> secondary alcohol
NaBH4 and distill
how are nitriles made?
nucleophilic addition with the CN- nucleophile
how do you prepare acyl chlorides from carboxylic acids?
SOCl2
what is required for the esterification of carboxylic acids
warm concentrated sulphuric acid with alcohol
acyl chloride + alcohol or phenol —–>
(warm with conc H+)
ester + HCl
acid anhydryde + ____ —-> ester + ______
alcohol
carboxylic acid
how do you turn an acyl chloride to a carboxylic acid?
add water (byproduct HCl)
acyl chloride + NH3 —–> _____
amide + HCl
acyl chloride + _____ —-> N-substituted amide + HCl
R—NH2
what is required for the acid hydrolysis of esters?
what technique is used?
reflux/ water/ dilute acid
what is the hydrolysis of esters
spits up an ester
what are the products of acid hydrolysis of ester
alcohol and carboxylic acid
what is are the conditions and products of alkaline hydrolysis of an ester
reflux/ source of OH- eg NaOH
produces a salt and alcohol
why can an amine act as a base
the lone pair on the nitrogen can accept a proton to form a diative covalent bond
what is required to prepare a primary amine
react a haloalkane with excess ammonia and ethanol solvent
nitrobenzene + 6[H]—–> _____
and conditions
phenylamine and 2H2O
conditions: reclux/ conc HCl and tin catalyst
what two groups do amino acids have
NH2 and COOH
amino acid + acid —->____
(reacts with NH2)
amino acid + alkali —–>_____
salt + water ( reacts with COOH)
amino acid + alcohol —->___
conditions: conc acid and heat
ester + water
hydrolysis is the splitting up by water
what is required for the hydrolysis of nitriles?
dilute acid and water (alcohol and ammonium salt is made)
CH3CN +2H2 —->
(nickel catalyst)
what is produced and what is this reaction
CH3CH2NH2
reduction
what is an amide link
H
|
N – C
||
O
what must there be for condensation polymerisation?
two functional groups
