Chapter 27 - Amines, Amino Acids, Polymers Flashcards
1° amines?
have one alkyl chain attached to the N (so 2H too)
2° amines?
have 2 alkyl chains attached to the N (so 1 H)
3° amines?
have 3 alkyl chains (so no H) attached to the N
how to name short primary amines?
- alkyl prefix
- then add ending amine
how to name short secondary and tertiary amines?
- di/tri alkyl ➡ how many alkyl groups attached to the N
- amine ending
how to name longer amines?
- amino prefix
- name the rest of the chain as usual
benzene and an amine gr is?
phenylamine
pH of amines?
- 9/10
- weak alkaline
amines solubility?
- can bond w water
- weak IDFs between molecules, easy to overcome
as C chain length ⬆, the solubility of the amine ?
solubility ⬇ as C chain length ⬆ as IDFs increase so the organic molecule stays bonded together
ammonia + water reversible ➡
NH4+ + OH-
formation of ammonia?
N2(g) + 3H2 (g) RA 2NH3(g)
- the haber process
- Fe(s) catalyst
ammonia acting a base equation?
NH3 + H2O ➡ NH4+
When ammonia acts as a base?
ammonium salt formed
structure of ammonia?
pyramidal, 107°
structure of methylamine?
pyramidal, 107°around N
109.5°, tetrahedral around C
Amines also react with acids to ?
form ammonium salts
amine groups mean?
H bonds between molecules
phenylamine?
has higher e- density than benzene bc of NH2
neutralisation?
if there r 2 N, then 2 protons (H+) are added
aliphatic =
chains and rings but NOT benzene rings
aromatic =
benzene ring
preparation of 1° aliphatic amines?
R: DRY (to stop alcohol formation) NH3 in excess (to prevent further subs)
C: in ethanol, reflux
CH3Cl + 2NH3 ➡ CH3NH2 + NH4Cl
preparation of 1° aliphatic amines: why is ammonia left w + charge?
one e- from lone pair went to C in bond
how do we prepare aromatic amines?
reduction (addition of H) of nitrobenzene
preparation of aromatic amine 1?
R: Sn (tin) and conc HCl
C: reflux
Eq: nitrobenzene + 6[H] ➡ phenylamine + 2H2O
preparation of aromatic amine 2?
phenylamine + HCl ➡phenylammonium chloride salt (C6H5NH3Cl)
Reverse the reaction:
C6H5NH3Cl + NaOH ➡ phenylamine + NaCl + H2O
Further nucleophilic substitution: preparation of a secondary amine?
CH3Cl + 2NH3 ➡ CH3NH3 + NH4Cl
ammonia is NOT in excess
Further nucleophilic substitution: preparation of a tertiary amine?
react a secondary amine with CH3Cl
why can’t be use ammonia and benzene to make phenylamine?
- NH3 = nucleophile
- Benzene takes part in electrophilic reactions
- phenyl is e- dense, repels nucleophiles
NS to form an amine always also forms?
an ammonium salt
v
vv
v
v
how many optical isomers does a molecule with 2 chiral carbon atoms have?
4
features that allow a molecule to be described as an AA?
amine group AND CA group
in an alpha amino acid?
NH2 and COOH bonded to the same C
when an AA is in alkaline conditions?
both COOH lose their H+ and react w the metal ion e.g. COO-Na+
when an AA is in acidic conditions?
NH2 gains a H+ to become N+H3 and reacts w negative ion
ethanoic acid vs glycine: solubility and pH
Ethanoic acid: ph4, red, soluble as 1 layer
gly: neutral - 5/6 (fewer H+) - dissolved
NH2 and COOH almost cancel out
ethanoic acid vs glycine: + Mg
Ethanoic acid: squeaky pop, vigorous reaction
gly: green quickly, little fizzing, no squeaky pop
ethanoic acid vs glycine: indicator and NaOH
Ethanoic acid: low pH - more H+
gly: more alkaline, higher pH - less H+
ethanoic acid vs glycine: + Na2CO3
Ethanoic acid: fizzing, limewater bubbling
gly: blue, no fizzing
ethanoic acid vs glycine: ethanol and conc H2S04?
Ethanoic acid: fizzing, strong smell
gly: milder smell, fewer COOH as internal ionisation
AA: phenol FG is ?
acidic
AA: whatever O does in an organic compound,
sulfur does too
NH2 is?
the amine group
amino acids reactions?
- nucleophilic
* neutralisation
Amine neutralisation reaction
CH3NH2 + HCl ➡ CH3NH3+Cl-