December Mocks - Reaction pathways/organic synthesis and qualitative analysis/identifying funtcional groups Flashcards
alkane —> haloalkane
Cl2/Br2
uv light
alkene —> alcohol
steam
H3PO4 catalyst
alkene —> haloalkane
what mechanism is this?
gaseous hydrogen halide
gases mixed if alkene is gas
bubble through alkene if alkene is liquid
electrophilic addition mechanism
alkene —> dihaloalkane
observations?
what mechanism is this?
Cl2/Br2
observations:
orange to colourless
electrophilic addition mechanism
alkene —> alkane
mixed with H2
423K
Ni catalyst
alcohol —> alkene
alcohol heated under reflux
presence of a conc. acid catalyst (conc. H2SO4 or conc. H3PO4)
primary alcohol —> aldehyde
alcohol gently heated
acidified potassium dichromate
aldehyde distilled off immediately
primary alcohol/aldehyde —> carboxylic acid
alcohol heated strongly under reflux
excess acidified potassium dichromate
observations:
orange to green
secondary alcohol —> ketone
alcohol heated under reflux
oxidising mixture such as aqeous solution of acidified potassium dichromate
alcohol —> haloalkane
alcohol heated under reflux
sodium halide
presence of acid catalyst (eg H2SO4)
hydrogen halide forms reacts with alcohol to produce haloalkane + water
haloalkane —> alcohol
what mechanism is this?
what is this reaction used for?
heat under reflux with:
aqeous alkali (NaOH)
or
water in the presence of AgNO3 and ethanol
nucleophilic substitution mechanism
(used to compare the rates if hydrolysis of diff H-X bonds)
benzene —> halobenzene
what mechanism is this?
Cl2/Br2
halogen carrier catalyst
electrophilic substitution mechanism
benzene —> nitrobenzene
what mechanism is this?
conc. HNO3
presence of conc. H2SO4
50 degrees water bath - reacts slowly
electrophilic substitution mechanism
benzene —> alkyl benzene
what mechanism is this?
excess benzene
chloroalkane
AlCl3 - halogen carrier catalyst
electrophilic substitution mechanism
benzene —> phenylethanone
what mechanism is this?
ethanoyl chloride AlCl3 - halogen carrier catalyst -60 degrees anhydrous conditions 30 mins reflux
electrophilic substitution mechanism
phenol —> 2,4,6 - tribromophenol
observations?
aqeous solution of bromine
observations:
white precipitate formed (2,4,6-tribromophenol)
bromine goes orange to colourless
phenol —> 2/4-nitrophenol
dilute HNO3
mixture of 2-nitrophenol and 4-nitrophenol formed
acyl chloride + ammonia —> ?
primary amide + hydrochloric acid
acyl chloride + primary amide —> ?
secondary amide + hydrochloric acid
acyl chloride + alcohol —> ?
ester + hydrochloric acid
acly chloride + phenol —> ?
phenyl -oate + hydrochloric acid
acyl chloride + water —> ?
carboxylic acid + hydrogen chloride gas
carboxylic acid —> acyl chloride
SOCl2
acyl chloride distilled off
+ SO2 + HCl
acid anhydride + alcohol —> ?
conditions?
acid anyhdride + alcohol —> ester + carboxylic acid
gentle heating
carboxylic acid + alcohol —> ?
conditions?
carboxylic acid + alcohol —> ester + water
alcohol warmed with carboxylic acid
conc. H2SO4 catalyst
aldehyde/ketone —> primary/secondary alcohols
conditions?
what mechanism is this?
warmed with NaBH4
aqeous conditions
reduction
nucleophilic addition mechanism
aldehyde/ketone —> hydroxynitriles
what mechanism is this?
(increasing the carbon chain)
KCN
dilute acid
aqeous conditions
nucleophilic addition mechanism
alkaline hydrolysis of esters
ester + NaOH—> carboxylate salt + alcohol
heat ester under reflux with aqeous NaOH/KOH
acid hydrolysis of esters
ester + H20 —-> carboxylic acid + alcohol
heat ester under reflux with dilute aqeous H2SO4 or dilute HCl
reversible
acid above reversible sign
haloalkane —> (aliphatic) amines
preparation of aliphatic amines
heated excess ethanolic ammonia >mixture of amines and their salts is formed aqeous alkali >amines produced
haloalkane + ammonia —> primary amine
haloalkane + primary amine —> secondary amine
haloalkane + secondary amine —> tertiary amine
haloalkanr + tertiary amine —> quaternary ammonium salt
nitrobenzene —> phenylamine
preparation of aromatic amines
heated under reflux tin + conc HCL(reducing agents) >forms phenylammonium chloride excess NaOH >forms phenylamine
amino acid + acid —> ?
ammonium salt
amino acid + alkali (NaOH/KOH) —> ?
carboxylate salt + water
amino acid + alcohol —> ?
conditions?
ester + water
heated with alcohol
conc. H2SO4 present
haloalkane —> nitrile
NaCN/KCN
ethanol
nitrile —> carboxylic acid
acid hydrolysis of nitriles
heat nitrile under reflux
dilute aqeous acid catalyst (eg HCl)
RCN + 2H20 + HCl —> RCOOH + NH4Cl
nitrile —> amine
reduction of nitriles
transition metal (eg Ni)
H2 (g)
150 degrees
how do you identify an alkene
add bromine water dropwise
observation:
bromine water decolourises from orange to colourless
how do you identify a haloalkane
add silver nitrate and ethanol and warm to 50 degrees in a water bath
observation:
chloroalkane - white precipitate forms slowly
bromoalkane - cream precipitate forms slower than iodo but faster than chloro
iodoalkane - yellow precipitate forms rapidly
how do you identify phenols
phenols acts as weak acids and react with solutions of strong bases (eg NaOH aq)
phenols don’t react with carbonates
how do you identify carbonyl compounds
add 2,4-dnp
observation:
orange/yellow precipitate forms
how do you identify aldehydes
Tollen's reagent aldehydes are oxidised to carboxylic acids silver ions reduced to silver solid observation: silver mirror forms
how do you identify primary and seconday alcohols and aldehydes
add acidified potassium dichromate
warm in water bath
observation:
orange to green
how do you identify carboxylic acids
add aqeous sodium carbonate
react to form carbon dioxide
observation:
effervescence
