Amides Flashcards
Are amides reactive or unreactive?
- Unreactive
Why are amides more stable than esters and are they more or less reactive ?
- lone pair on N is stabilised by resonance
- amides are less reactive than esters due to stabilisation
What are 1°, 2º, 3° amides?
1° has to 2h’s
2ºhas 1H
3°has no H
what is the “double whammy” effect in amides?
- amides exhibit both hydrogen bonding and strong dipole-dipole interactions
(between N and O) - contributing to higher boiling points.
how many electrons are shared in an amide’s π orbitals?
- an amide has 4 electrons shared between 3 π orbitals.
what is the hybridization of nitrogen in an amide?
- nitrogen is sp² hybridized
- planar
what is rotation around the amide bond like ?
- restricted allows cis and trans orientations
In which solvent is the rate of rotation fastest?
- the rate of rotation is fastest in cyclohexane
- least polar solvent.
how do solvents like water and DMSO interact with organic molecules?
- possess strong dipole moments
- interact with organic molecules through charges and dipoles.
why does cyclohexane facilitate faster rotation?
- cyclohexane has no dipole moment, leading to less interaction with organic molecules and faster rotation.
What is a common method for synthesizing amides from carboxylic acids?
- reaction can be facilitated by using coupling agents like DCC (dicyclohexylcarbodiimide).
what are the methods for synthesizing amides?
- Carboxylic Acid + Amine
- Acyl Chloride + Amine
- Acid Anhydride + Amine
- Reduction of Nitriles (using lithium aluminum hydride)
Acid hydrolysis of amines ?
- forms ammonium salt
what is the dehydration of amides?
- amides can be dehydrated to form nitriles by heating with dehydrating agents (e.g., POCl₃ , SOCL2
What is the general reaction for dehydrating an amide to a nitrile?
RCONH2 ——–> RCN+H20
