Test your abilities

[politoxicomania]

For those who have just bought some flasks, chemicals and other lab-ware from an great german auction house and now want to try some reaktions at home.
To get familiar with preparative chemistry ull have to learn by doing. Heres a test-reaktion for those who plan to work with air-sensitive materials.

(Co(NH3)6)Cl2

Chemicals:
dest.Water
CoCl2*6H2O
konz. NH3

preparation:
10 g CoCl2*6H2O are soluted in little airfree water (cooked water). While heating penetrate this solution with konz. Ammoniak till everythings soluts. Filter the solution hot and add Ethanol (airfree!) till u can see first precipitate in the hot solution. Cool down under water and filter off the crystalls and wash first with konz.NH3/ethanol(airfree 1:1), the same mix but (1:2) and at least with airfree ethanol sattisfied with NH3.
 Dry the crystalls over KOH in vacuum.
The crystalls have caracteristical color.

Warning:
Dont try this at home. This is for hobby-chemists with a little lab, a smoke-outlet, the right glass-ware, knowledge
and (your neighbourhood will thank u) a system to collect inorganic garbage.

This is a normal reaktion for students in the first preparative semester and didactically well studied.

[Gringo]

Was wilslt du uns damit sagen?? Das wir alle hohl in der Birne sind odda was??

[politoxicomania]

Nein....  No

Das vorgestellte Präparat ist eine schöne Übung. Just practice.

Wie ich schon sagte ist dieser Versuch didaktisch gut gewählt für Anfänger.
Probiers doch einfach mal aus.
Die Chemikalien sind einfach und billig und es kann nix schlimmes passieren. Man bekommt durch diese Reaktion einen Eindruck wie sauber man arbeiten sollte bzw. muss.

Bevor sich ein newbee an gefährlichere Reaktionen traut sollte er doch erst mal was ungefährliches probieren .....

[Gringo]

Well... sounds good...Okay i'll give it a try! but the only problem is, the translation. verstehst du?

[politoxicomania]

[politoxicomania]

Here is the second reaktion SWIM can practice without destroying himself.

Representation of  benzyle alcohol.

Execution: A roundbottomflsk, with magnet agitator, reflux-condenser and dropping funnel becomes equipped with a mixture from 11 g (0,10mol) Benzaldehyd, 30 ml methanol and 13 g formaldehyde (30%ige solution; 0,13mol) fed and on 65° C heats up.
To this solution one drips a solution of 17 g (0,30mol)  potassium hydroxide in 10 ml water within 15 min.
The beginning is heated up still further 40 min. on 70° C and cooked in the end still 20 min to the return flow.
After the cooling one dilutes  with 50 ml water and extracts 3 time with ever 30 ml ether.
The united organic phases are dried afterwards over sodium sulfate and the solvent is destilled off.
The arrears are distilled in the water jet vacuum.

With the crossed Cannizaro reaction the alcohol function should develop mainly at the more highly substituted aldehyde; it is however not to exclude also methanol developed.

Analytic:
alphaD20 = 1,541
T~ 90°C at 17mmHg

Yields should be about 50-60%


And again:
Warning:
Dont try this at home. This is for hobby-chemists with a little lab, a smoke-outlet, the right glass-ware, knowledge
and (your neighbourhood will thank u) a system to collect organic garbage.

[hypo]

no offense, polytoxicomania, i really appreciate your effort,
but.... i guess in the eyes of most bees disproportionating
a benzaldehyde amounts to a pretty severe sacrilege.  

[politoxicomania]

I dont know but it seems to me that u ar no newbee.

This is the newbee forum and these tests are adressed to newbees.

I dont know on which gradates you work but im sure to know a reaktion to practice you fits.
Theorie is one thing but to do it practically is another thing.

[politoxicomania]

cis-Norboren-5,6-dicarbonacidanhydrid

Chemicals
Maleinacidanydrid
Acetic ester
Ligroin
Cyclopentadien

Cyclopentadien:
Dimer Cyclopentadien is distilled with Cu or FeCl2 as katalyst in a 100 ml flask equiped with 20 cm vigreux, claisen adapter and liebig condenser to yield monomer Cp.

Reaction
 An erlenmeyerflask equiped with 4 g (40mmol) maleinacidanhydrid in 20ml acetic ester and 13 ml ligroin is cooled to 0°C. Now 3,8g (60mmol) dried, monomer Cp from the above step is added while shaking. After the exothermic reaction a white product should krystalize over night.
Recrystalisation from acetic ester.
Yield should be 40-70%.
Fp=165°C

Lit.
O. Diels, K. Alder, Liebigs Ann. Chem. 460 (1928) 98.
L. F. Fieser und K. L. Williamson, 3.Edition.,P. 118, Lexington 1973.

[politoxicomania]

5,5´-Diphenylhydantoin

Chemicals:

Benzil (Dibenzoyl)
Harnstoff (H2NCONH2)
KOH
Ethanol
Methanol

Reaction:
A 250ml roundbottomflask equipped with stirrer, dropping-funnel and heater is filled with a solution of 4,2 g (20mmol) Benzil in 100ml Ethanol. Over the dropping funnel a solution of 5,61 g (0,1mol) KOH in 10 ml Water is added and the mixture is heated to reflux. After 2 hours the mixture is cooled down to RT and 300ml water is added. Filter the solution  and saturate it with solid CO2.
A precipetate should form, collected by sucktion filtration and recrystallized from minimum amount of methanol.

Analytic:
yield : 50-60%
FP: 293,5°C

Lit.:
R. C. Hayward, J. Chem. Educ. 60 (1983) 512.
H. Beyer und W. Walter, Lehrbuch der organischen Chemie, 19. Aufl., S.669, S. Hirzel Verlag, Stuttgart 1981.