Use of the grignard solution, Chemistry

Use of the Grignard solution to prepare 2,2,6-trimethyl-5-phenylheptan-3-one:

Prepare a solution of your enone (5.64 g; 0.030 moles) in dry ether (30 mL) and add it to the dropping funnel. Add it dropwise, over 30 min, to the stirred and ice-cooled solution of 2-propyl magnesium bromide. When addition is complete, remove the slush-bath and continue stirring for a further 30 min.

Hydrolyse the mixture by pouring it cautiously onto a mixture of ammonium chloride (16 g) and crushed ice (70 g) in a beaker, stirring as you do so with a glass rod. When the ice has melted, separate the two layers and extract the aqueous layer with ether (2 x 50 mL; there is no need to use dry ether at this stage: why not?) keep the ether layer. Back-wash the combined ethereal layers with saturated brine (40 mL)

Dry the ether layer over anhydrous magnesium sulphate, filter and evaporate thoroughly (use a clean rotary evaporator!) to dryness, in a tared RB flask. Determine the weight of the crude product obtained.

Recrystallise your product (even if it is at present a liquid) from a mixture of ethanol/water (95:5, v/v), using 2 mL of solvent for each gram of product. If no crystals appear on cooling the filtered solution in ice, add a seed crystal of product (available from a demonstrator) to induce crystallisation. After allowing a thick precipitate to form, collect it on a Hirsch funnel, filtering rapidly to avoid redissolving. Pull the cake as dry as possible, then finally dry (24 hr) on a watch glass, in air, in a cupboard.

Posted Date: 2/11/2013 6:35:52 AM | Location : United States







Related Discussions:- Use of the grignard solution, Assignment Help, Ask Question on Use of the grignard solution, Get Answer, Expert's Help, Use of the grignard solution Discussions

Write discussion on Use of the grignard solution
Your posts are moderated
Related Questions
Metal ion configurations in high and low spin octahedral complexes(with)table

Define Colligative Properties of A Dilute Solution? The colligative properties of a solution are usually considered to be: 1. Freezing-point depression: the decrease in the

Free-radical mechanism: Free-radical polymerisation is started by organic peroxide or other reagents that decompose to give free radicals.


why pcl3 is less polar than sicl4

physical properties of salicylic acid?

Q. Explain Colligative properties of Solutions? Colligative properties  of solutions are those properties which depend on the concentration of the solution rather that the ty


Q. Explain the structure of Single covalent bonds? Ans. Atoms tend to achieve the stable electron configuration of a noble gas when forming a bond. In covalent bonding thi

Orthoboric acid H 3 BO 3 commonly known as boricacid and Meta boric acid HB0 3 , are two well-known and important oxoacids of boron. On a large scale, H 3 BO 3 is prepared by the