Synthesis Routes Flashcards
How do you test for what sort of alcohol you have and how do the different ones react?
warm with acidified potassium dichromate
PRIMARY- orang dichromate turns green as aldehyde forms (eventually carboxylic acid)
SECONDARY- orange dichromate turns green as ketone forms
TERTIARY- no change
How do you distinguish between an aldehyde and a ketone (two ways)?
TOLLENS’- aldehyde forms silver mirror, no reaction with ketone.
FEHLING’S-aldehyde gives brick red precipitate, no reaction with ketone.
What is the test for unsaturation (double bond)?
Shake with orange bromine solution. Solution will quickly decolourise if substance is unsaturated.
How do you distinguish between haloalkanes?
Remove halide ion by adding NaOH.
CH3CH2X + OH- = CH3CH2OH + X-
Add nitric acid (get rid of any ions that might interfere) and then add silver nitrate solution.
Precipitate of silver halide.
Colour tells you what halide it is and double check by seeing solubility in ammonia solution
What colour precipitate do the different silver halides make and what is their solubility in ammonia?
F- = no precipitate/ - Cl- = white precipitate/dissolves in dilute ammonia solution Br- = cream precipitate/ dissolves in conc. ammonia I- = yellow precipitate/ insoluble in conc. ammonia
What is percentage yield and how do you work it out?
How much product you expect to get from the reactants.
% yield= actual yield/theoretical yield X 100
What is atom economy and how do you work it out?
The proportion of reactant atoms that become part of the desired product.
% atom economy= mass of desired product/ total mass of reactants X 100
How do you make a haloalkane from and alkane?
free radical sub.
Cl2
U.V light
What are the conditions for making secondary/ tertiary amines, their salts and quarternary ammonium salts from a haloalkane?
ammonia, heat
What are the conditions for making a primary amine from a haloalkane?
ammonia, heat
What are the conditions for making a nitrile from a haloalkane?
KCN(aq), ethanol, reflux
What are the conditions for making a primary amine from a nitrile?
LiAlH4
dilute H2SO4
What are the conditions for making an alcohol from a haloalkane?
warm, NaOH(aq), reflux
What are the conditions for making and alkene from a haloalkane?
NaOH, ethanol, reflux
What are the conditions for making a haloalkane from an alkene?
HBr, 20C