Preparation of dimethylbutan, Chemistry

Assignment Help:

Preparation of dimethylbutan:

Procedure:

Prepare a mixture of 3,3-dimethylbutan-2-one (trivial name pinacolone; 20.0 g, 0.200 moles), redistilled benzaldehyde (24.0 g, 0.226 moles; see Note 1 if you need to redistil it yourself), 95% ethanol ( ‘rectified spirit'; 75 mL), water (26 mL) and 10% aqueous sodium hydroxide solution (20 mL) in a 500 mL round-bottomed flask equipped with a stirrer guide and overhead mechanical stirrer.

Stir for 6 hours at ambient temperature (this is important).

Dilute with an equal volume of water, and extract the organic product with three separate portions of diethyl ether (60 mL) using an appropriately sized separating funnel. Wash the combined ethereal extracts with water (4 x 60 mL; Note 3), then dry over anhydrous magnesium sulphate (Note 4).

Remove the desiccant by filtration (fluted filter paper, gravity) and the solvent by rotary evaporation over a water-bath using a tared RB flask (Note 5). Determine the mass of the crude product (Note 6).

It is critically important that you do the following distillation carefully: any residual starting materials will interfere with the next step in the reaction.

Purify your product by distillation under reduced pressure, using an efficient water-pump (Notes 7 and 8). Collect the lowish-boiling fore-run in receiver flask 1, and the constant-boiling pure product in receiver flask 2, over a temperature range of no more than 20.(See Note 6.) Record the bp/pressure at which the product distils, record its mass and calculate your percentage yield. Run a IR spectrum of your different fractions and check the purity of your product (marks will be awarded for purity and it will be worth repeating the distillation if your sample is contaminated).


Related Discussions:- Preparation of dimethylbutan

Chemical bonding, explain why carbon tetra-chloride does not dissolve in wa...

explain why carbon tetra-chloride does not dissolve in water?

What is the iupac name of carbon?, IUPAC name is given to compounds. Carbon...

IUPAC name is given to compounds. Carbon is an element so it will bw called as carbon only. eg. hydrocarbons - CH4=methane                            C2H6=Ethane

Physical properties of group 3 elements, Explain trend in variation of the ...

Explain trend in variation of the atomic size properties from Boron and Thallium

Chemical kinetics of the peroxodisulfate ion, Chemical Kinetics of the Pero...

Chemical Kinetics of the Peroxodisulfate Ion The peroxodisulfate  ion is one of the strongest oxidants that are  called, although the oxidation reaction is relatively slow.

Chemical change in matter, A chemical change takes place when one or more...

A chemical change takes place when one or more substances change into new substances. A chemical change is as well known as a chemical reaction. The emergence of new substances

Help!, Calculate the theoretical voltage of the following galvanic cell: Ni...

Calculate the theoretical voltage of the following galvanic cell: Ni|10^-3 mol/l Ni(NO3)2 || 1 mol/l AgNO3|Ag. Write the equations for the half reactions of this cell.

The electronic structure of four elements, The electronic structure of four...

The electronic structure of four elements A, B, C, D are: (1) 1s 2                   (2) 1s 2 , 2s 2, 2p 2 ,              (3)  1s 2, 2s 2 , 2p 5 ,

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd