Midterm Key is in ERES file
Class Average: 75.5
High: 100 Low: 27
Today:
“Unknowns”:
- Brief Review of Preliminary tests and Solubilities
- Aldehydes and Ketones
- Alcohols and Phenols
(Unknown #1)
Family Science
Night Volunteers:
Please see me after
class
Next time:
Carboxylic acids
Esters
Amines
(Unknown #2)
Preliminary Tests
•
Mp. (range!) for solids
•
Bp., refractive index for liquids
•
Ignition test
•
Test for unsaturation
•
Beilstein test for halogen (p.626)
Solubility Tests
(pp. 626 – 627)
What type of information do you get if your unknown
1. is soluble in water?
2. is soluble in NaOH and in NaHCO3?
3. is soluble in NaOH only, not in NaHCO3?
4. is soluble in dilute HCl solution?
5. is soluble only in conc H2SO4?
6. is not soluble in any of the above solvents?
Aldehydes and Ketones
functional group?
• Preliminary tests
• Solubility
• Classification tests
• Derivatives
• Spectra
•Typical properties? Mp.? Bp.?
• Solubility?
Classification Tests for
Aldehydes and Ketones
• Preliminary tests
• Solubility
• Classification tests
• Derivatives
2,4-dinitrophenylhydrazone
• Spectra
also a good derivative!
1. What are desirable properties of a derivative?
2. What is the purpose of preparing a
derivative?
Aldehydes and Ketones
• Preliminary tests
To distinguish between aldehydes and ketones:
• Classification tests
• Solubility
• Derivatives
• Spectra
• Tollens Test:
• Jones (chromic acid): check reagent! Test is also positive for …..?
• Schiff reagent: check reagent!
Always do with a known compound to compare!
Aldehydes and Ketones
Derivatives
• Preliminary tests
• Solubility
• Classification tests
• Derivatives
Imines:
2,4-dinitrophenylhydrazone
oxime
semicarbazone
• Spectra
• Preliminary tests
• Solubility
• Classification tests
• Derivatives
• Spectra
Question….
• What characteristics would you look for
– in the IR spectrum of an aldehyde
– In the HNMR of an aldehyde
– In the CMR of an aldehyde?
Aldehydes and Ketones
IR:
H-NMR:
Alcohols and Phenols
Solubility distinction?
• Preliminary tests
• Solubility
• Classification tests
• Derivatives
• Spectra
Solubility:
Alcohols: “neutral”;
Phenols: very weak acids, pKa around 10, except nitrophenols!
Classification tests (many also positive with amines…):
• Jones
• Lucas test for 3o alcohols, 2o alcohols (slow):
• Phenols only: Complexation with Fe 3+
OCH 3
OH
Anthocyanin Colors
+
O
HO
OCH 3
O - glucose
OH
Cl
Malvidin
an anthocyanin in blue grapes
-
• Preliminary tests
Alcohol and Phenol Derivatives
• Solubility
• Classification tests
• Derivatives
• with 3,5-dinitrobenzoyl chloride
• Spectra
• urethanes
Similarly: Naphthyl urethanes
Phenols only: Bromoderivatives
• Preliminary tests
• Solubility
• Classification tests
• Derivatives
• Spectra
IR:
H-NMR:
Exchange with
D2O
Alcohols
Phenols
IR
H-NMR
Next time:
• Carboxylic Acids and Esters
• Amines
Review this class!