28 Flashcards
What is a nitrile
Organic group of CN, triple bond
How to make nitrile
NACN/KCJN+ haloalkane = nitrile and nach
This is nucleophile subsition and increases chain lmebthjn
Aldehydes and ketones and nitriles?
Why isn’t HCN used fire time?
Will react with NaCN /h2sp4 basic,sly HCN overall to reduce and become nydroxynittiled
Why isn’t HCN used first time for these reduction reactions
Because HCN is poisonous , so NACN and H2so4 is used to improve safety
2 reactions nuture,s
One is nitrile and 2H2 = AN AMINE
Ni catalyst is needed
- check by seeing how many Hydrogens added on each atom, 2 in csbrinaCN 2 in amine
2) HYDROLYSIS OF NITRILE
Nitrile + 2 water + HCL = CARBOCYLIC ACID and Ammonium salt
The whole N gets cut
Two ways to add candies to be bend
Use alkylation of ACYLATION
Remmeber hydrolysis 2 water Rand HCL
2 h2 and in cat,ayt to become amine
What is filterstion under reduced pressure used for
Bsdicslly just s better way to filter solid then using filter paper alone
How to do it
Need a Büchner flask, funnel, filter paper, and access to a vacuum outlet t
1) connect one end of rubber tubing to a vacuum outlet and other to the ACTUAL BUCHNER FLASK
2) ATTSCH THE BUCHNER funnel to thr flask using s rubber Bing for tight fit
3) turn thr vacuums outler on, should feel good suction
4) out filter paper in and wet it with solvent , should suck down
5) now poor mixtures in and rinse
6) then allow the collecyed crustal to dry out under suction to form crystals
Yiu have no speedster the solid, but it’s still impure
How does recrystallisation work the idea?
Basically depends on if the DESIRED PRODUCT has a different solubility with a chosen solvent compared to the impurited
How to do
If solvent flammable snot
Solvent flammable like alchol, heat it up using a water bath, else if wster then can use Bunsen burner
Once not enoijhj tip it into the beaker containing impure sample
AIM IS TO SLOWLY TIP IT AND STIR, YOU WANT THR MINIMUM SMOUNT OF HOT SOLVENT TO DISSOLVE
Once dissolved, let it cool for crustal to form, these will be pure, when no more crystals form , this may still have liquid in it
NOW MUST RETRIEVE THESE HSIJG FILTERSTION UNDER REDUCED PRESSURE SGSIN!
Again recrystallisation summarise
Minimum amount of hot solvent to dissolve impure sample
Let it cool until no more cyestsls formed
Retdireve by filterstion under reduce dpressure again
How to and why do melting point determination
Melting point determination is for to check purity. If it is pure it will melt over a SHARP RANGE OF 1 OR 2 DEGREES compared to actual melting point
What si the melting range
How do you know fi pue the
When it starte to melt to when it’s fully melted
The organic pure will have a SHARP RSNGE
More impure, longer to melt, thus will melt over a LONGER RANGE
And of course had to coincide with actual melting pints
- also impure tends to have LOWER MELTING POINTS
Impure sample summarised
- not only longer melting point range
- lower melting point than what it should be
How to PREPARE FOR melting point determination
1) glass capillary and hold one end in Bunsen burner snd fotogene to melt snd SEAL THST END
2) let it cool, then dab it into sample to force solid in
3) place it in appears ist
