ORGANIC CHEM REACTIONS Flashcards
(29 cards)
How to prepare alkanes
Reduction of alkenes
H2 gas with Ni catalyst and heat or Pt/Pd catalyst at rtp
What do alkanes form
Halogenoalkanes
Excess halogen or alkane depending on product, UV light/heat
How to prepare alkenes
1.Dehydration of alcohols
Excess conc H2SO4 and heat or Al2O3 and heat
2.Dehydrohalogenation of halogenoalkanes
NaOH or KOH in alcohol and heat
What do alkenes form
1.Halogenoalkanes
HX at rtp
2.Di-substituted halogenoalkanes
X2 in CCl4 solvent at rtp
3.Alcohol with halogen subbed
X2 in water at rtp
4.Alcohol
cold conc H2SO4, followed by heat with water
5.Diol
KMnO4 in NAOH at cold or rtp
6.Carboxylic Ketone or CO2
KMnO4 in H2SO4 and heat
How to test for alkenes
Decolorization of a solution of orange-red Br2 in CCl4 or orange Br2 in H2O
What does benzene form
- Halogenation to form benzene with halogen sub
X2 gas with anhydrous FeCl3 at rtp - Alkylation to form methylbenzene for eg
RX with anhydrous AlCl3 at rtp
3.nitrobenzene
conc HNO3 acid with conc H2SO4 as catalyst heat at 60 degrees under reflux
4.cyclohexane
hydrogen gas with Ni catalyst at 150 degrees and high pressure
What does methyl benzene form that is diff from benzene
1.nitrobenzene can occur at lower temp of 30 degrees
2.side chain oxidation to aldehyde with weak OA and Carboxylic with benzylic H
KMnO4(aq) with H2SO4(aq)
How to prepare halogenoalkanes
- From alkenes
HX at rtp - From alcohols
PX3, SOCl2 and HX and heat under reflux or PCl5 at rtp
What can halogenoalkanes form
Nucleophilic sub
1. Form alcohol
NaOH or KOH with heat under reflux
- Form nitriles
alc KCN with heat under reflux - Form amine
alc NH3 in excess heated under pressure in a sealed tube
Elimination to form alkene
alc NaOH or KOH with heat under reflux
How to test for RX
1.Heat with NaOH(aq)
2.Acidify with dilute HNO3
3.Add aq AgNO3
white if Cl
cream if Br
yellow if I
How to form alcohols
1.From halogenoalkanes
NaOH(aq) or KOH(aq) and heat under reflux
2.From alkenes
cold conc H2SO4 followed by H2O warm
3.Reduction from carboxylic acids, aldehydes and ketones
LiAlH4 in dry ether (works for all), NaBH4 in methanol or H2 with Pt
What do alcohols form
- Halogenoalkanes
PX3, PCl5 and SOCl2 all with heat - Alkenes
excess conc H2SO4 and heat - Redox with reactive metal to give salt
- Carbonyl compounds and carboxylic acids
K2Cr2O7 and H2SO4 with heating under reflux (heat under immediate distillation for aldehyde) - Esters with Acyl chlorides and carboxylic acids
conc H2SO4 and heat - Tri-iodomethane formation
I2 in NaOH(aq) and heat
What do phenols form
- Salts with reactive metals or acid base
- mono or tri subbed nitrophenol
dilute HNO3 for mono and conc for tri - mono or tri subbed bromophenol or any halogen
Br2 in CCl4 solvent for mono and in aq for tri
How to test for alcohols
reactive metal producing hydrogen gas
How to test for phenol
aq FeCl3 forming a violet colouration
How to prepare aldehydes and ketones
- From Alcohols
For aldehydes - K2Cr2O7 in H2SO4(aq) and heat with immediate distillation
For ketones -K2Cr2O7 in H2SO4(aq) and heat under reflux - From oxidisation of alkenes
- hot acidified KMnO4
What can carbonyl compounds form
- Step up reaction
HCN with trace NaOH(aq) or with trace NaCN(aq) as catalyst
note that the product can undergo acid hydrolysis to form carboxylic or reduction
- React with 2,4 dinitrophenylhydrazine
Forms an orange ppt also the test for carbonyl compounds - Reduction to form alc
LiAlH4 in dry ether or … - Oxidation of aldehydes to carboxylic
K2Cr2O7 or KMnO4 both with H2SO4(aq) and heat under reflux - Tollens and Fehlings reagent with heat forming silver mirror and brick-red ppt
- tri-iodomethane formation
I2(aq) with NaOH(aq) and heat
How to prepare carboxylic acids
3 ways
1. Oxidation of aldehydes and primary alcohols
K2Cr2O7 and KMnO4 (aq) with H2SO4 and heat under reflux for K2Cr2O7
- Hydrolysis of nitriles
H2SO4(aq) and heat or NaOH(aq), heat, followed by H2SO4 - distinguishing test as NH3 is produced which turns red litmus blue - Side-chain oxidation of alkylbenzene
KMnO4(aq) and H2SO4 or in alkaline medium then add H2SO4 after
What do carboxylic acids form
5 diff products
1. Salt formation with reactive metal, alkali, carbonates and hydrogen carbonates
-distinguishing test form phenols and alc as CO2 gas is produced
- Ester with alcohols
concentrated H2SO4 and heat - Conversion to acyl chlorides
SOCl2 or PCl3 both w heat
PCl5 at rtp
PCl5 and SOCl2 with have white fumes - Reduction to primary alcohols
LiAlH4 in dry ether at rtp - Decarboxylation to alkanes
soda lime(CaO and NaOH mixture) and heat
How to form esters
From carboxylic acid/acyl chloride reaction with alcohol
concentrated H2SO4(aq) and heat
Reactions of esters
1.Carboxylic acid or carboxylic salt through acid or alkaline hydrolysis
H2SO4(aq) and heat or NaOH(aq) and heat
What reactions do Acyl chlorides undergo
- Forms carboxylic acid through hydrolysis
H2O at room temp - Condensation with alc and phenols to form esters
with alc: alcohol only no heating required
with phenol: requires phenol and NaOH to form stronger nucleophile C6H5O- - Condensation with Ammonia to form pri, sec and tertiary amides
pri: excess NH3
sec and tertiary: excess acyl chloride
How to prepare amines
- Nucleophilic sub of halogenoalkanes
Heat with alc NH3 in a sealed tube under pressure - Reduction of amides
LiAlH4 in dry ether at rtp - Reduction of nitriles
LiAlH4 in dry ether at rtp or H2 gas with ni…
How to prepare Phenylamine
- Reduction of nitrobenzene
Sn and concentrated HCl. heat under reflux followed by addition of alkali
btw how to form nitrobenzene
1.From benzene or alkyl benzene
conc nitric acid and conc H2SO4(aq) and heat at 60 and 30 degrees respectively
2.From phenols
dilute nitric acid or conc nitric acid forming mono and tri subbed
