Type of compound:Aldehyde
Alcohol
Amine
Ketone
Identify an Unknown
Procedure
1. Physical PropertiesMelting point or boiling point
2. Functional Group
Infrared spectrum
NMR Spectrum
Solubility
Classification Tests
3. Solid Derivative
Measure boiling point of liquids
Distill your unknown and note the boiling point
If can’t distill or not enoughsample use this technique.
Functional GroupCarbonyl Group (1650 - 1725 cm-1)?
Yes No
AldehydeKetone
NMR
Aldehyde Ketone+ -
AlcoholAmine
BroadOH in IR
Yes NoAlcohol Amine
(Basic?)3700 - 4000 cm-1
YesPrimary or Secondary
NoTertiary
2,4-dinitrophenylhydrazine test
NH2NH
NO2
NO2
Aldehyde or ketone
R-C-R
O+ NH2NH
NO2
NO2
NNH
NO2
NO2CR
R
2,4-dinitrophenylhydrazone
C
ONH2R C
OH
NHR
NRC
Iodoform TestReagent: NaOH and I2 (NaOI)
CCH3
O
RI2, NaOH
RCOOH + CHI 3Yellow
CCH3
O
RI2, NaOH
RCOOH + CHI3Yellow
Iodoform Test
CHCH3
OH
RI2, NaOH
RCOOH + CHI3Yellow
Ceric Nitrate Test for Alcohols
(NH4)2Ce(NO3)6 + ROH
(NH4)2Ce(NO3)5OR
+ HNO3
Amines
1. Odor
2. If not soluble in water they maydissolve in dilute aqueous acid (HCl).
3. Water solutions of amines arebasic to litmus.
Hinsberg Test for Amines
SO2Cl
Benzenesulfonyl Chloride
Hinsberg Test for Amines
Primary: Soluble. PPT if add HClSecondary: Insoluble
Tertiary: Tends not to react
DerivativesAldehydes and Ketones
1. 2,4-dinitrophenylhydrazone
2. Semicarbazone
NH2NHC
O
NH2
semicarbazide
+ RC
O
R NNHCNH2CR
RO
semicarbazone
Alcohol Derivative
O2N
O2N
C ClO
O2N
O2N
C OROROH
3,5-dinitrobenzoyl chloride
3,5-dinitrobenzoate
Amine DerivativesPrimary and Secondary Amines
CO
Cl + RNH2 CO
NHR
Benzoyl Chloride Benzamide
SO2Cl + RNH2 SO2NHR
Benzenesulfonyl Chloride Benzenesulfamide
Sample Unknown
B.p. =198-200o
DNP = 231-235o
C
O
CH3
acetophenone
Sample Unknown
B.p. = 80 - 85o
3,5-dinitrobenzoate= 119 - 121o
CCH3 CH3
H
OH
isopropyl alcohol
B.p = 106o
3,5-dinitrobenzoate85o
CH2OHCH
CH3
CH3
isobutyl alcohol
B.p. = 160o
3,5-dinitrobenzoate:108-110o
OH
H
cyclohexanol
B.p. = 155-157o
2,4-DNP = 158 -160o
B.p. = 180 -183o
Benzenesulfonamide110 - 112o
Benzamide 160 - 163o